Download pdf - AMZ 1120LT08 LSF (Propulsion Motor)

User’s Manual

Serial no.ABB ref.Project:

ABB

Synchronous MachineAMG 1600LH14 LSE

4603047-95383HF101-103

May 2010 SHI HN1810 Ruan(Angola) LNG#1 Gen

6.Manual

Table of Contents1. Introduction ........................................................................................................ 1

1.1. General information ................................................................................... 11.2. Important note ........................................................................................... 11.3. Limitation of liability ................................................................................. 21.4. Site conditions .......................................................................................... 2

2. Transport and storage ............................................................................................ 32.1. Transport and unpacking ............................................................................. 3

2.1.1. Protective measures prior to transport .................................................. 32.1.2. Lifting the machine .......................................................................... 32.1.3. Lifting of unpacked machine ............................................................. 42.1.4. Checks upon arrival and unpacking ..................................................... 5

2.2. Storage .................................................................................................... 62.2.1. Short term storage (less than 2 months) ............................................... 62.2.2. Long term storage (2-6 months) ......................................................... 62.2.3. Very long term storage (over 6 months) ............................................... 82.2.4. Regular checks during storage ........................................................... 82.2.5. Storage and care after installation ....................................................... 8

3. Installation and alignment ...................................................................................... 93.1. Preparations for installation ......................................................................... 9

3.1.1. General ......................................................................................... 93.1.2. Check of foundation ....................................................................... 10

3.2. Installation .............................................................................................. 103.3. Alignment .............................................................................................. 11

3.3.1. Rough levelling ............................................................................. 113.3.2. Rough axial alignment .................................................................... 123.3.3. Air gap check ............................................................................... 123.3.4. Alignment .................................................................................... 133.3.5. Final alignment ............................................................................. 143.3.6. Correction for thermal expansion ...................................................... 16

3.4. Final inspection and installation .................................................................. 163.4.1. Covers and enclosures .................................................................... 16

4. Mechanical and electrical connections .................................................................... 174.1. General .................................................................................................. 174.2. Mechanical connections ............................................................................ 17

4.2.1. Connection of water pipes ............................................................... 174.3. Electrical connections ............................................................................... 17

4.3.1. General information ....................................................................... 174.3.2. Connection of main power cables ..................................................... 184.3.3. Earthing connection ....................................................................... 184.3.4. Insulation distances of main power connections ................................... 194.3.5. Connection of auxiliaries and instruments .......................................... 204.3.6. Automatic Voltage Regulator (AVR) ................................................. 204.3.7. Installation of Automatic Voltage Regulator (AVR) .............................. 22

5. Commissioning .................................................................................................. 235.1. General .................................................................................................. 235.2. Check of mechanical installation ................................................................. 235.3. Check of electrical installation .................................................................... 245.4. Insulation resistance measurements ............................................................. 245.5. Automatic Voltage Regulator (AVR) ............................................................ 255.6. Starting .................................................................................................. 255.7. Shut down .............................................................................................. 26

iii

Synchronous Machine AMG 1600LH14 LSESection 6 - Manual

6. Operation .......................................................................................................... 276.1. General .................................................................................................. 276.2. Normal operating conditions ...................................................................... 276.3. Protection of synchronous generators ........................................................... 286.4. Start-up procedure .................................................................................... 28

6.4.1. Start interlocking ........................................................................... 296.5. Continuous supervision ............................................................................. 296.6. Shut down procedures ............................................................................... 29

7. Maintenance ...................................................................................................... 317.1. Preventive maintenance ............................................................................. 317.2. Safety precautions .................................................................................... 317.3. Maintenance program ............................................................................... 32

7.3.1. Recommended maintenance program ................................................ 347.4. Maintenance of general construction ............................................................ 38

7.4.1. The tightness of fastenings .............................................................. 387.4.2. Vibration and noise ........................................................................ 407.4.3. Rotor construction control ............................................................... 407.4.4. Checks during running of the machine ............................................... 40

7.5. Maintenance of lubrication system and bearings ............................................. 437.5.1. Lubrication ................................................................................... 437.5.2. Sleeve bearings ............................................................................. 457.5.3. Oil leakage of sleeve bearings .......................................................... 467.5.4. Bearing insulation resistance check ................................................... 507.5.5. Bearing clearance measurements ...................................................... 51

7.6. Maintenance of stator and rotor winding ....................................................... 527.6.1. Particular safety instructions for winding maintenance .......................... 527.6.2. Timing of the maintenance .............................................................. 537.6.3. The correct operating temperature ..................................................... 537.6.4. Insulation resistance test ................................................................. 537.6.5. Polarization index .......................................................................... 587.6.6. High voltage test ........................................................................... 587.6.7. Fault searching methods .................................................................. 597.6.8. Tan delta-measurements .................................................................. 597.6.9. Surge comparison test ..................................................................... 597.6.10. Visual winding inspection .............................................................. 607.6.11. Cleaning the windings ................................................................... 617.6.12. Drying ....................................................................................... 647.6.13. Partial discharges ......................................................................... 657.6.14. Varnishing of the windings ............................................................ 667.6.15. Other maintenance operations ........................................................ 66

7.7. Maintenance related to electrical performance, excitation, control, andprotection ..................................................................................................... 66

7.7.1. Exciter insulation resistance measurement .......................................... 667.7.2. Protection trips .............................................................................. 677.7.3. Maintenance of Automatic Voltage Regulator (AVR) ............................ 677.7.4. Pt-100 resistance temperature detectors .............................................. 687.7.5. Insulation resistance measurement for auxiliaries ................................. 707.7.6. Diode fault ................................................................................... 70

7.8. Maintenance related to thermal performance and cooling system ....................... 717.8.1. Maintenance instructions for air-to-water heat exchanger ...................... 717.8.2. Disassembly and remounting of cooling system ................................... 73

8. Troubleshooting ................................................................................................. 788.1. Mechanical performance ........................................................................... 788.2. Lubrication system and bearings ................................................................. 79

iv


8.2.1. Lubrication system and sleeve bearings .............................................. 798.3. Thermal performance ................................................................................ 80

8.3.1. Thermal performance, air-to-water cooling system ............................... 808.4. Electrical performance .............................................................................. 81

8.4.1. Electrical performance and excitation system of generators .................... 819. After sales and spare parts .................................................................................... 82

9.1. After Sales .............................................................................................. 829.1.1. Site Services ................................................................................. 829.1.2. Spare Parts ................................................................................... 829.1.3. Support and Warranties ................................................................... 829.1.4. Support for Service Centers ............................................................. 829.1.5. After Sales contact information ........................................................ 82

9.2. Spare parts .............................................................................................. 839.2.1. General spare part considerations ...................................................... 839.2.2. Periodic part replacement ................................................................ 839.2.3. Need of spare parts ........................................................................ 839.2.4. Selection of the most suitable spare part package ................................. 849.2.5. Typical recommended spare parts in different sets ................................ 849.2.6. Order information .......................................................................... 86

10. Disposal and recycling instructions ....................................................................... 8710.1. Introduction .......................................................................................... 8710.2. Average material content .......................................................................... 8710.3. Recycling of material required for transport ................................................. 8710.4. Recycling of the complete machine ............................................................ 87

10.4.1. Dismantling of the machine ........................................................... 8710.4.2. Frame, bearing housing, covers and fan ............................................ 8810.4.3. Components with electrical insulation .............................................. 8810.4.4. Permanent magnets ...................................................................... 8810.4.5. Hazardous waste .......................................................................... 8910.4.6. Landfill waste ............................................................................. 89

v


Chapter 1 Introduction

1.1. General informationThis User's Manual contains information on the transport, installation, operation andmaintenanceof the synchronous machine manufactured by ABB.

This manual provides information regarding all aspects of operation, maintenance and supervisionof the machine. Careful study of the contents of this manual and other machine relateddocumentation before any actions are taken is necessary to ensure proper functionality and a longlifetime of the machine.

Actions shown in this manual are only to be performed by trained personnel with previousexperience in similar tasks, and authorized by the owner of the equipment.

This document and parts thereof must not be reproduced or copied without the express writtenpermission of ABB, and the contents thereof must not be imparted to a third party nor be usedfor any unauthorized purpose.

ABB constantly strives to improve the quality of the information provided in this User’s Manual,and will welcome any improvement suggestions. For contact information, see Chapter 9.1, AfterSales.

These instructions must be followed to ensure safe and proper installation,operation and maintenance of the machine. They should be brought to theattention of anyonewho installs, operates or maintains this equipment. Ignoringthe instruction invalidates the warranty.

NOTE:

1.2. Important noteThe information in this document may sometimes be of a general nature and applicable to variousmachines produced by ABB.

Where a conflict exists between the contents herein and the actual machinery supplied, the usermust either make an informed engineering judgement as to a course of action or, if any doubtexists, contact ABB.

The safety precautions shown in Section 1, Introduction must be observed at all times.

Safety is dependent on the awareness, concern and prudence of all those who operate and servicemachines. While it is important that all safety procedures be observed, care near machinery isessential - always be on your guard.

To avoid accidents, safety measures and devices required at the installationsite must be in accordance with the instructions and regulations stipulated forsafety at work. This applies to general safety regulations of the country inquestion, specific agreements made for each work site and safety instructionsincluded in this manual and separate safety instructions delivered with themachine.

NOTE:

Introduction - 1


1.3. Limitation of liabilityIn no event shall ABB be liable for direct, indirect, special, incidental or consequential damagesof any nature or kind arising from the use of this document, nor shall ABB be liable for incidentalor consequential damages arising from use of any software or hardware described in this document.

The warranty issued covers manufacturing and material defects. The warranty does not cover anydamage caused to the machine, personnel or third party by improper storage, incorrect installationor operating of the machine. The warranty conditions are in more detail defined according toOrgalime S2000 terms and conditions.

The warranty issued is not valid, if the operation conditions of the machineare changed or any changes in the construction of the machine, or repair workto the machine have been made without prior written approval from the ABBfactory, which supplied the machine.

NOTE:

Local ABB sales offices may hold different warranty details, which arespecified in the sales terms, conditions or warranty terms.

NOTE:

For contact information, see the back page of this User’s Manual. Please remember to providethe serial number of the machine when discussing machine specific issues.

1.4. Site conditionsThis machine is to be used on a site with environmental conditions according to ABB specifications(listed in Section 1, Introduction and Section 3, Technical Specification).

Please refer to the applicable certificate in Section 2, Certificates. Special conditions stipulatedin the certificate must be strictly followed.

Introduction - 2


Chapter 2 Transport and storage

2.1. Transport and unpacking

2.1.1. Protective measures prior to transportThe following protective measures are taken before delivery of the machine from the factory. Thesame protective measures should be taken, whenever the machine is moved:

• All synchronous machines delivered as a unit are provided with an axial movement lockingdevice protecting the bearings against damages during transport. The locking device must beattached whenever the machine is transported.

• Machined metal surfaces, such as the shaft extension, are coated with an anti-corrosive coatingbefore delivery.

• The bearings are flooded with oil during the tests prior to delivery. This gives sufficientprotection against corrosion.

• The cooler is drained.

During shipping the machine should be placed under deck.

2.1.2. Lifting the machineBefore the machine is lifted, ensure that suitable lifting equipment is available and that personnelis familiar with lifting work. The weight of the machine is shown on the rating plate, dimensiondrawing and packing list.

Use only the lifting lugs or eyes intended for lifting the complete machine.Do not use any small additional lifting lugs or eyes available, as they are thereonly for service purposes.

NOTE:

The center of gravity of machines with the same frame may vary due todifferent outputs, mounting arrangements and auxiliary equipment.

NOTE:

Check that eyebolts or the lifting lugs integrated with the machine frame areundamaged before lifting. Damaged lifting lugs must not be used.

NOTE:

Lifting eyebolts must be tightened before lifting. If needed, the position ofthe eyebolt must be adjusted with suitable washers.

NOTE:

2.1.2.1. Lifting the machine packageThe package has marks showing where the lifting wires are attached.

Lifting must be performed with great care and using long enough slings.

See Figure2-1, Lifting of the machine, lifting from belowFigure2-2, Lifting of the machine, liftingthrough the cover

For details, see the lifting drawing in Section 4, Mechanical Drawings.

Transport and storage - 3


Do not attempt to lift the machine from the red attaching points!NOTE:

If the ambient temperature is below -20 ºC, the machine must not be lifted oroperated without permission from the manufacturer.

NOTE:

Figure 2-1 Lifting of the machine, lifting from below

Figure 2-2 Lifting of the machine, lifting through the cover

2.1.3. Lifting of unpacked machineLifting must be performed with great care and using slings long enough to assure the lifting anglerequirements. If the requirements are not met, there is a risk of damage. See Figure 2-3, Liftingan unpackedmachine . For more details, see the lifting drawing in Section 4, Mechanical Drawings.

The machine must be lifted from its frame. Do not attempt to lift the machinefrom the top cover!

NOTE:



Figure 2-3 Lifting an unpacked machine

2.1.4. Checks upon arrival and unpacking

2.1.4.1. Check upon arrivalInspect the machine and the package immediately upon arrival. Any transport damage must bephotographed and reported immediately, i.e. within less than one (1) week after arrival, if thetransport insurance is to be claimed. It is, therefore, important that evidence of careless handlingis checked and reported immediately to the transport company and the supplier. Use checklistsin Section 9 COMMISSIONING REPORT.

A machine that is not installed immediately upon arrival must not be left without supervision orwithout protective precautions. For more details, see Chapter 2.2, Storage.

2.1.4.2. Check upon unpackingPlace the machine so that it does not hinder the handling of any other goods, and on a flat,vibration-free surface.

After the package has been removed, check that the machine is not damaged and that all accessoriesare included. Tick off the accessories on the packing list which is enclosed. If there is any suspecteddamage or if accessories are missing, take photographs thereof and report this immediately to thesupplier. For contact information see Chapter 9, After sales and spare parts. Use checklists inSection 9 COMMISSIONING REPORT.



2.2. Storage

2.2.1. Short term storage (less than 2 months)The machine should be stored in a proper warehouse with a controllable environment. A goodwarehouse or storage place has:

• A stable temperature, preferably in the range from 10 ºC (50 °F) to 50 ºC (120 °F). If theanti-condensation heaters are energized, and the surrounding air is above 50 ºC (120 °F), makesure that the machine is not overheated.

• Low relative air humidity, preferably below 75 %. The temperature of the machine should bekept above dew point to prevent moisture from condensing inside the machine. If the machineis equipped with anti-condensation heaters, they should be energized. Verify the operation ofthe anti-condensation heaters periodically. The anticondensation heaters shall be de-energisedwhen air temperature inside the machine enclosure exceeds + 40 ºC. If the machine is notequipped with anti-condensation heaters, an alternative method of heating the machine andpreventing moisture from condensing in the machine must be used.

• A stable support free from excessive vibrations and shocks. If vibrations are suspected to betoo high, the machine should be isolated by placing suitable rubber blocks under the machinefeet.

• Air which is ventilated, clean and free from dust and corrosive gases.

• Protection against harmful insects and vermin.

If the machine needs to be stored outdoors, the machine must never be left ‘as is’ in itstransportation package. To store the machine outdoors:

1. Take the machine out from its plastic wrap.

2. Cover the machine to prevent rain from entering it. The cover should allow ventilation ofthe machine.

3. Place the machine on at least 100 mm (4”) high rigid supports. This prevents moisture fromentering the machine from below.

4. Provide with good ventilation. If the machine is left in its transportation package, make largeenough ventilation holes in the package.

5. Protect from harmful insects and vermin.

2.2.2. Long term storage (2-6 months)In addition to the measures described in Chapter 2.2.1, Short term storage (less than 2 months),some extra measures needs to be taken depending on whether the machine is stored indoors oroutdoors.

Be careful not to damage the seals or the bearings.NOTE:

Storage indoors

To store the machine indoors:



1. If the machine is stored in its transportation package, make big enough holes on the sides ofthe transportation package so that the D-end and ND-end of the machine are accessible.

2. Protect the shaft and the sealing points, as well as all bearing parts against corrosion. Shaftand bearing seals should be treated with an anti-corrosive agent (e.g. LPS 3, Holt Lloyd,USA). The bearing should be filled with protective oil, for example

- Esso: Rust-Ban 623

- Gulf: Gulf No-Rust Engine Oil Grade 2

- Mobil: Mobilarma 524

- Shell: Shell Ensis Engine Oil 20

3. If the protection made by the manufacturer has been removed, protect the unpainted surfacessuch as shaft extensions, coupling halves and jacking screws with suitable anti-corrosionagent.

4. If the machine has been delivered in fully assembled condition, turn the rotor approximately10 revolutions once per every 3 months to maintain a protective oil film on the bearingsurfaces.

5. Fill self-lubricated bearings with oil, or connect flood lubricated bearings to the lubricationsystem. If this cannot be done, the bearing shells should be taken out, see Storage outdoors.

Storage outdoors

To store the machine outdoors:

1. Take all the measures described in Storage indoors.

2. Cover the machine completely with a big enough waterproof cover.

3. Remove the side and end covers of the machine.

4. Push strong cardboard pieces into the air gap between the main machine stator and rotor sothat the rotor may be supported by the stator.

5. Dismount the bearing instruments.

6. Dismount the seals and the upper parts of the bearing housings.

7. Remove the upper parts of the bearing shells and dismount the eventual oil rings.

8. Lift the rotor up (approximately 0.5 mm) until the bearing shells do not carry the weight ofthe rotor.

9. Turn the lower bearing shells 180 º over the shaft and remove them.

10. Lower the rotor so that it rests on the stator (cardboard pieces in between).

11. Protect the bare shaft surfaces and shells with anti corrosive agent.

12. Mount the bearing housings and seals (seals have to be loosened) and protect the seals withanti-corrosion agent.



13. Store the bearing shells in a clean and dry place.

2.2.3. Very long term storage (over 6 months)Clean all the protected surfaces listed in Chapter 2.2.1, Short term storage (less than 2 months)and Chapter 2.2.2, Long term storage (2-6 months), and renew the anti-corrosive treatment every12 months. Otherwise follow the instructions for shorter storage periods.

2.2.4. Regular checks during storageThe following checks should be made regularly during storage.

Every month:

• Check that the anti-condensation heaters are working.

• Check that the ventilation works.

Every 3 months:

• Check the insulation resistance, see Chapter 7.6.4, Insulation resistance test

• Check that there is no corrosion on the surfaces. If corrosion is observed, remove the corrosionand protect the surfaces.

• Check that the anti-corrosion agents have not cracked.

Every 6 months:

• Dismount the bearing housing upper cover and check the shaft and the bearing housinganti-corrosion protection.

2.2.5. Storage and care after installationIf the machine will not be in operation for a longer period of time after installation, the samemeasures as inChapter 2.2.1, Short term storage (less than 2months) should be applied. Rememberto rotate the shaft 10 revolutions at least every 3 months. Self-lubricated bearings must be filledwith oil.



Chapter 3 Installation and alignment

3.1. Preparations for installation

3.1.1. GeneralGood planning and preparation results in correct installation, assures safe running conditions andmaximum accessibility.

During installation, general as well as local safety instructions must be followed.

Install anti-condensation heaters to keep the machine interior dry when thereis a risk of condensation.

NOTE:

Protect the machine against dust and rain.NOTE:

Tools and materials

Suitable materials for set-up and shimming as well as other auxiliary tools for installation arenormally not included in the ABB delivery. Auxiliary tools for installation are to be supplied bythe customer.

The following should be available on site if required:

• attachments for gauges, extension brackets and other alignment tools

• a lever for turning the rotor

• other auxiliary tools and materials for the installation, such as hydraulic jacks and bracketplates with adjusting screws

• for suitable oil qualities, see Chapter 7.5.1, Lubrication.

Pouring oil into the bearings

Before turning the rotor, suitable bearing oil must be filtered through a 10 micrometer mesh, andpoured into the bearings.

To pour oil into the bearings:

1. Turn the rotor using a lever.

2. Pour oil continuously into the bearings at both ends of the machine while turning the rotor,see Figure 3-1, Pouring oil into the bearings.

Installation and alignment - 9


Figure 3-1 Pouring oil into the bearings

General tightening torques

General tightening torques for screws are given in Chapter 7.4.1, The tightness of fastenings. Usethese values if no specific tightening torques are given in this manual or in the mechanical andelectrical drawings (see Section 4, Mechanical Drawings and Section 5, Electrical Drawings).

3.1.2. Check of foundationThe structural design of the foundation is not included in the ABB scope, and the customer or athird party is therefore responsible for this.

The installation of the machine should be planned as early as possible. Before lifting the machineonto the foundation:

• Check that the position of the anchoring or fixing holes and the height of the foundation arein agreement with corresponding measurements on outline and foundation drawings in Section4, Mechanical Drawings.

• Check that the foundation is flat. If any inclination has been agreed upon, the permissibleinclination must be stated on the installation drawing.

• Sweep or vacuum-clean the foundation some days before installation.

3.2. InstallationThe machine is normally transported and lifted as one ready assembled unit onto the foundation,see Section 4, Mechanical Drawings.

To install the machine:

1. Mount the coupling halves, if applicable.

2. Mount the machine on the foundation.

3. Level and align the machine roughly in axial and horizontal directions.



4. Align and couple the rotor with the driven machine.

5. Fasten the machine initially to the foundation.

6. Check air gaps and adjust as necessary.

7. Re-check the alignment. Fine adjust if necessary.

8. Tighten and lock bolts and install dowel pins.

9. Install accessories.

More detailed instructions for installation are given in the following chapters or in instructionssupplied by driven/driving machine manufacturer.

Bearing sealings may have been loosened for transportation. Check the sealings and, if necessary,re-align them (see bearing documentation is Section 7, Accessory information).

3.3. AlignmentIn order to ensure a long and satisfactory lifetime of both the driving and driven machine, themachines have to be properly aligned to each other. This means that the radial, as well as theangular deviation between the two shafts of the machine has to be minimized. The alignment mustbe performed with great caution because alignment errors will lead to bearing and shaft damages.

Before alignment remove the transport locking device according to the instructions in the TransportLocking drawing in Section 4, Mechanical Drawings. The transport locking device is normallypainted red.

3.3.1. Rough levellingTo rough level the machine:

1. Remove the anti-corrosive coating from metal surfaces that have to be uncoated duringnormal operation.

2. Check the coupling instructions and fit. Preheat the coupling hub as necessary and mount iton the machine shaft.

3. Lift the machine up and move it onto the bed plate.

4. Align the machine visually and put pieces of sheet metal below the jacking screws to protectthe bed plate surface.

5. Turn the jacking screws until they carry the weight of machine.

Check that the machine is radially and axially leveled by placing a spirit level on the horizontalsurfaces of the frame and rotor shaft as shown in Figure 3-2, Placement of the spirit level. Makeadjustments by placing shims under the feet. The machine must be supported by all feet.



Figure 3-2 Placement of the spirit level

3.3.2. Rough axial alignmentIf the rotor has axial float, check the mechanical center position of the rotor.

The running center is not the same as the magnetic center because themachine's radial cooling fan has an axial component that will affect the rotorrunning position.

NOTE:

If there is no thrust bearing, the machine cannot withstand any axial force from the driven machine.In this case, the axial force must be carried by the driven machine, and the coupling must be oflimited axial float type.

If there is an axially locating bearing on the machine, make sure that continuous free axialmovement is possible between the coupling halves (excluding rigid couplings) in order to permitthermal expansion of the machine shaft without damaging the bearings.

When the machine stands axially in its right position, leave all adjusting jacking screws onlylightly tightened.

3.3.3. Air gap checkTo check the air gap of the electrical machine between the stator and the rotor:

1. Remove the side covers, or where applicable, the end covers of the machine frame.

2. Push a wedge-shaped measuring strip in the air gap at the middle of one pole in foursymmetrically chosen rotor positions.

3. Turn the rotor correspondingly.

Where applicable, there is a hole in the fan through which the measuring can be done.

Make sure that the bearings are filled with oil before turning therotor.

NOTE:

Centering of the rotor, i.e. the air gap, is adequate when a single measuredvalue does not deviate more than 10 percent from the mean value.

NOTE:

To adjust the air gap of the stator and the rotor of the electrical machine:

1. Loosen the bolts retaining the bearing housing to the bearing support.

2. Remove the dowel pins.



3. Move the complete bearing housing.

Adjustment is finalised by adding or removing shims between the bearing housing and thebearing housing support, i.e. the pedestal.

After the air gap of the stator and the rotor of the electrical machine have been checked andadjusted, the air gap between the exciter stator and rotor, at the ND-end of the machine, has to bechecked in four symmetrically chosen positions. The exciter air gap is adjusted by moving theexciter stator.

Figure 3-3 Air-gap between stator and rotor

After the adjustment of the air gap, tighten all the fastening bolts, see Table 7-2, General tighteningtorques . Verify the air gap once more where appropriate dowel pins are inserted.

3.3.4. AlignmentAfter the machine has been roughly positioned, as described in Chapter and 3.3.2, Rough axialalignment, the final alignment can start.

Alignment must be performed with great caution. Failure to do so can resultin serious vibrations and damage to both driving and driven machine.

NOTE:

The alignment is done in accordancewith the recommendations given by the couplingmanufacturer.Parallel, angular and axial alignment of the machine is required. Some standard publications giverecommendations for coupling alignment, see for example BS 3170:1972 "Flexible couplings forpower transmission".

In accordance with common practice, parallel and angular misalignment should not exceed 0.05- 0.10 mm and axial misalignment should not exceed 0.10 mm, see Figure 3-4, Definition ofmisalignment . The corresponding run-out is 0.10 - 0.20 mm for parallel and angular misalignment,and 0.20 for axial misalignment.



Figure 3-4 Definition of misalignment

Parallel misalignment Δr

Angular misalignment Δb

Axial misalignment Δa

Definite alignment tolerances are impossible to state as many factors influence the tolerances.Too large tolerances will cause vibration and may possibly lead to bearing or other damages.Therefore, it is recommended to aim at as narrow tolerances as possible. Maximum permissiblemisalignments are shown above. For definitions of misalignment, see Figure 3-4, Definition ofmisalignment .

The tolerances given by the coupling manufacturers indicate tolerances forthe coupling, not for the driving-driven machine alignment. The tolerancesgiven by the coupling manufacturer should be used as a guideline for thealignment only if they are narrower than the maximum permissiblemisalignments shown above.

NOTE:

3.3.5. Final alignmentTo align the machine:

1. Make sure that the machine stands on its jacking screws.

2. Rotate the rotor and check the axial end float, see Chapter 3.3.2, Rough axial alignment.

Lubricate the bearings at regular intervals during the final alignmentin accordance with Chapter 3.1, Preparations for installation.

NOTE:

3. Mount the alignment equipment. If gauges are used, it is practical to adjust the dial gaugein such a way that approximately half of the scale is available in either direction. Check therigidity of the gauge brackets in order to eliminate the possibility of sag, see Figure 3-5,Alignment check with gauges.



Figure 3-5 Alignment check with gauges

4. Measure and note readings for parallel, angular and axial misalignment in four differentpositions: top, bottom, right and left, i.e. every 90°, while both shafts are turnedsimultaneously. Record the readings in the Commissioning Report in Section 9.

5. Align the machine vertically by turning the jacking screws or the adjustment screws, or byjacking with hydraulic jacks.

To facilitate the alignment in the vertical plane, jacking screws are fitted to the feet of thehorizontal machine. See Figure 3-6, Vertical positioning of machine foot.

The alignment accuracy of the machine is sometimes affected by the thermal expansion ofits frame. See Chapter 3.3.6, Correction for thermal expansion.

Figure 3-6 Vertical positioning of machine foot

6. Measure the distance between the bottom of the machine feet and the bed plate and makecorresponding solid blocks or wedges or reserve a necessary number of shims.

7. Fit the solid blocks or shims under the stator feet. Slacken the jacking screws and tighten thefixing bolts.

8. Check the alignment again. Make corrections if necessary.

9. Check the air gap of the machine and the exciter.

10. Draw up a record for future checks (Section 9, Check Lists).

11. Re-tighten the nuts and lock them by tack welds or hitting sufficiently hard with a centerpunch.



3.3.6. Correction for thermal expansionThermal expansion should be taken into account when aligning the machine. The temperature ofthe machine is lower during installation than it will be during operating conditions. For this reasonthe shaft centre is going to lie higher when the machine is in operation.

Depending on the type of coupling, the distance between the machine and the driven equipmentmay have to be compensated because of thermal expansion.

The upward thermal expansion of the electrical machine can be estimated using the followingformula:

ΔH = a × ΔT × H [mm]a = 10 × 10-6 K-1whereΔT = 40 KH = shaft height [mm]

Due to the thermal expansion of the electrical machine, the vertical movement of the shaft isapproximately 0.1 mm for each 10 °C difference in temperatures as illustrated in Figure 3-7, Thecorrelation between thermal expansion and machine temperature.

Figure 3-7 The correlation between thermal expansion and machine temperature

3.4. Final inspection and installation

3.4.1. Covers and enclosuresAfter the machine has been erected and aligned, and its accessories have been installed, checkcarefully that no tools or foreign objects have been left inside the enclosures. Clean also any dustor debris.

When installing the covers, check that all sealing strips are intact before mounting them.

Store alignment and assembly accessories together with the transport locking devices for futureuse.



Chapter 4 Mechanical and electrical connections

4.1. GeneralMechanical and electrical connections are made after the installation and alignment procedures.The mechanical connections include the connection of air ducts, water tubes and/or oil supplysystem where applicable.

The electrical connections include the connection of main and auxiliary cables, earthing cablesand possible external blower motors.

In order to determine proper actions, see Section 4, Mechanical Drawings and Section 5, ElectricalDrawings.

Additional installation holes or threads should never be drilled through theframe, as this may damage the machine.

NOTE:

4.2. Mechanical connections

4.2.1. Connection of water pipesThe cooling water pipes should be laid so that they do not impede service andmaintenance. Installthe piping so that only a short part needs to be dismantled to clean the coolers and no stress isapplied to the connection flanges of the cooler. The cooling water pipes should be insulated, andthere should be a shut-off valve in the supply pipe. The pipes to and from the coolers must becleaned before they are assembled.

For more detailed information regarding the coolers, refer to Chapter 7.8.1, Maintenanceinstructions for air-to-water heat exchanger.

4.3. Electrical connections

4.3.1. General informationThe safety information in Section 1, Introduction, Chapter 5 Safety Instructions (High-voltageAC Machines) must be observed at all times. Study the connection diagrams delivered with themachine before starting the installation, see Section 5, Electrical Drawings.

Before you start the installation:

• Verify that the supply voltage and the frequency are the same as the values indicated on therating plate of the machine and in Section 3, Technical Specification.

• Make sure that the sizes of input cables are adequate for the maximum load current and inaccordance with local standards.

• Make sure that cable terminations are of appropriate type and of correct size.

• Check the connections of all devices, such as temperature probes.

Prior to installation it is important to check that the incoming cables are notconnected to the supply network. The cables should be grounded.

NOTE:

Mechanical and electrical connections- 17


4.3.2. Connection of main power cablesThe stator terminals are marked with the letters U, V and W according to IEC 34-8 or T1, T2,and T3 according to NEMA. Stripping, splicing and insulating of the high-voltage cables mustbe performed in accordance with the instructions delivered by the cable manufacturer. The lugsshould not be permanently tightened by busbars, but only attached (for checking of insulationresistance).

The cables must be supported so that no stress is applied to the busbars in the terminal box, seethe connection diagram in Section 5, Electrical Drawings.

When three-phase cables are used, the prescribed distance must be maintained between the leadsat intersections. Bracing and spacers should be used if necessary.

Check the phase sequence, see Figure 4-1, Phase sequence (IEC) and Figure 4-2, Phase sequence(NEMA) .

Figure 4-1 Phase sequence (IEC)

(CW = clockwise, CCW = counter clockwise)

Figure 4-2 Phase sequence (NEMA)

(CW = clockwise, CCW = counter clockwise)

4.3.3. Earthing connectionThe connection point for earthing can be found in a machine frame, see Figure 4-3, Connectionpoint for earthing cable. There are points for earthing of main cables and auxiliary cables interminal boxes. The machine earthing is designed so that the machine is safe when the earthingis done properly. The locations of the points can be found in main dimension and terminal boxdrawings in Section 4, Mechanical Drawings andSection 5, Electrical Drawings.

Do not remove or modify the internal earthings of themachine.Modificationsmay cause sparking or electric charges that can be dangerous.

NOTE:



Figure 4-3 Connection point for earthing cable

4.3.4. Insulation distances of main power connectionsThe connections of the main power cables are designed to withstand demanding operationconditions where the insulators can be subjected to dirt, humidity and surge voltages. In order toensure lasting and trouble-free running, it is therefore important that local requirements or otherapplicable standards for the insulation distances are met.

If no local requirements or other applicable standards are available, it is suggested that theminimuminsulation distances mentioned in Table 4-1, Recommended minimum insulation distances areused.

These distances apply both for insulation distances between two different phases, and for insulationdistances between one phase and the earth. Values for voltages not listed in the table can beobtained by interpolating.

The air insulation distance is the shortest distance through air between two points with differentelectrical potential (voltage). The surface insulation distance is the shortest distance along surfacesnext to each other between two points with different electrical potential (voltage).

Table 4-1. Recommended minimum insulation distances

Surface insulation distance (mm)Air insulation dis-tance (mm)

Main voltage (V)Finned surfaceEven surface

8106690121491000242717200036412630003945283300434931360050573641607080506000



Surface insulation distance (mm)Air insulation dis-tance (mm)

Main voltage (V)Finned surfaceEven surface

77895466008598597200120140801000014016392115001701981101380018621712015000

4.3.5. Connection of auxiliaries and instrumentsConnect the instruments and auxiliary equipment according to the connection diagram in Section5, Electrical Drawings. The locations of auxiliary terminal boxes are shown on drawings in Section4, Mechanical Drawings.

4.3.6. Automatic Voltage Regulator (AVR)

4.3.6.1. GeneralAVR (Automatic Voltage Regulator) is a device that continuously monitors the voltage at thevoltage regulating point of the system and automatically initiates corrective actions to maintainthe terminal voltage of the generator. AVR also controls that the synchronous generator operateswithin pre-set limits.

A three phase transformer supplies the excitation power to the field winding of the shaft drivenby a three phase exciter under the control of the AVR. A three phase voltage feedback is suppliedby the voltage transformer and a current feedback is provided by the current transformer. Thetransformers are installed in the generator.

Operational limits, such as over and under excitation, machine voltage and Volts/Hz, areimplemented in the AVR. Static reactive power compensation in parallel operation and severalother software functions are also available. The AVR is equipped with the PC software for theAVR.

More detailed information about the AVR used in the specific generator can be found in thefollowing sections:

• AVR manual, see Section 7, Accessory Information

• system description, see Section 3, Technical Specification

• layout and dimensions, see Section 4,Mechanical Drawings and Section 5, Electrical Drawings.

If the AVR is supplied as a loose item without the AVR plate, only the AVRmanual is included.

NOTE:



4.3.6.2. ConfigurationAVR is used as a single-channel system or a dual-channel system. AVR can function either inautomatic or manual mode in both systems.

Single-channel system

The voltage regulator with actual value reading and setpoint formation is active in the automaticmode. The limiter functions which protect the machine against excessive loads are also active inthe automatic mode. In addition to the actual voltage regulator function, reactive power or powerfactor regulators are also available. Reactive power and power factor regulators can be switchedon and off.

Reactive power and power factor regulators are not available in island systems.NOTE:

In the manual mode the actual value is formed from the measurement of the excitation currentand passed with the setpoint value to the excitation current regulator. The output from the regulatoris passed to a switch which is used to select the corresponding mode. This mode is only used fortest purposes and as an emergency regulator in the event of failure of the voltage regulator. Thelimiter functions are not active in this mode.

Dual-channel system

The dual-channel system increases the accessibility of the excitation system significantly. Thedual-channel system is equipped with two identical channels. Each channel has the same propertiesas a single-channel system. If one channel fails, the system switches to the other channel. Onlyone channel (main channel) is in operation at one time. The other channel (redundant channel) isin standby position and continuously monitors the active channel so that a smooth switchover ispossible at any time.

4.3.6.3. Boosting circuitIn case of short circuit in network or the generator bus bars, the stator voltage drops. Then it isprobable that the AVR loses its excitation power supply and is not able to provide desired amountof excitation current. It is, however, essential to excite the machine under short circuit to enablethe over current protection to trip the generator. For that reason there is a boosting circuit on theAVR plate.

The short-circuit current transformers (CTs) mounted inside the generator are wired to the boostinput. The CTs are rated for sustaining a short circuit current of at least 250 % of rated current inland applications and 300% in marine applications. In normal operation the boosting relay (NCcontacts) short-circuits the secondary of the CTs. If the AVR detects a short circuit (stator voltagedrops below a set level) it energizes the boosting relay. This opens the short circuit of the CTsand supplies current directly to the excitation field. Diodes are used parallel to the boosting circuitto ensure a free wheeling for the field current.

The excitation current limiter module is used to adapt the boosting current to a desired level. Seea separate instruction material.

Boosting circuit, including the CTs, must be dimensioned properly in orderto avoid harmful over voltages.

NOTE:



4.3.7. Installation of Automatic Voltage Regulator (AVR)

4.3.7.1. Mechanical installationFor fixing holes and dimensions, see AVR dimensions diagram in Section 5, Electrical Drawings.

The unit should only be installed in indoor areas which are dry and dust-free and do not containany gases, acid fumes or similar.

4.3.7.2. Earthing and wiringThe emission limits in accordance with standard EN 50081-2 (1993) will only be complied withif the connections for the power electronics supply and the field output are made using shieldedcables earthed at each end. We also recommend that shielded cables are used for the analog anddigital connections.



Chapter 5 Commissioning

5.1. GeneralCommissioning is not considered finalized before a commissioning report has been made anddistributed to all concerned parties (customer and supplier).

A commissioning report is a vital tool for future service, maintenance and troubleshooting.

The commissioning report has to be sent to ABB in order to obtain futurewarranty claims.

NOTE:

A recommended commissioning report can be found in Section 9, Check Lists.

General safety precautions must be followed during commissioning and all work has to beperformed by qualified personnel.

5.2. Check of mechanical installationBefore commissioning:

1. Check the alignment of the machine. Go through the alignment report and ensure that themachine is accurately aligned according to ABB alignment specifications in Chapter 3,Installation and alignment.

The alignment protocol should always be included in thecommissioning report.

NOTE:

2. Check that the machine is properly anchored to the foundation.

- Check for cracks in the foundation and the general condition of the foundation.

- Check the tightness of the fixing bolts.

3. Open the machine, and check that the air-gap is free. See Figure 3-3, Air-gap between statorand rotor and Chapter 3.3.3, Air gap check.

4. Before turning the rotor, check that the lubrication system is commissioned and running.

5. If possible, turn the rotor by hand and make sure that the rotor turns freely and that there areno abnormal sounds.

6. Check the assembly of the main terminal box and cooling system.

7. Check the connection of the oil and cooling water pipes. If applicable, check for leaks whenrunning.

8. Check the pressure and flow for oil and cooling water, if applicable.

9. Check that all transport locking devices are removed.

Commissioning - 23


5.3. Check of electrical installationThe power cables can be permanently connected to the terminals in the main terminal box afterthe stator insulation resistance has been measured, see Chapter 7.6, Maintenance of stator androtor winding.

Before commissioning, check the connection of power cables:

1. Check that the fixing bolts are tightened to the correct torque.

2. Check that the power cables are suitably routed and do not cause any additional strain to theterminal bars.

3. Check that the power cables are correctly stress-relieved.

4. Check the connections of the auxiliary equipment.

5. Check the tightness of the cable glands and enclosure sealing.

6. If the cable glands were delivered separately, check that the fixing bolts are tightened withthe correct torque.

5.4. Insulation resistance measurementsMeasure the insulation resistances of windings and all auxiliary equipment before making anyelectrical connections and applying voltage to the machine.

Measure the insulation of at least the following parts:

• stator and rotor winding

• exciter winding

• bearing insulation (if both bearings are insulated)

• Pt-100 detectors

• space heaters.

The measured values indicate the condition of the insulation between the winding (or other circuitto be tested) and the frame of the machine. For detailed information on how to conduct thesemeasurements see Chapter 7, Maintenance.

If the insulation resistance is under the specified value, it must be corrected before starting themachine. See Chapter 7, Maintenance for corrective actions.

Measure the insulation resistance well before the first start so you will have time for any necessarycorrective actions.

The winding must be dry during the test. Therefore the anticondensation heaters should be activeduring storage and installation.

Commissioning - 24


5.5. Automatic Voltage Regulator (AVR)

Pre-settings and testing by ABB

The AVR has been tested with the specific generator and all the basic settings have been modifiedand saved so that the AVR will also work at site. The correct AVR and the correct generator canbe identified by checking the serial numbers on the test report. See Section 8, Test Reports.

Settings used in testing can be found in Section 8, Test Reports.

Checking at site before first run

All the settings has to be checked once more at the site of the generator. If there is need to changethe settings it must be done by a qualified person such as an ABB or AVR representative.

Settings for the network must also be checked and verified.NOTE:

For detailed information about the settings and commissioning see Section 8,Test Reports and the system description in Section 3, Technical Specification.

NOTE:

5.6. Starting

Start-up of the machine

The starting of the machine depends on the application, but main guidelines are:

1. Switch the space heaters off if not operated by switchgear.

2. Start to rotate the machine.

3. Maintain rated speed.

4. Switch the machine excitation on.

5. Maintain rated voltage.

6. Check sychronizing parameters.

7. Synchronize the machine to the grid.

Recommended values for sychronizing are:

• ΔU = 2 %

• Δf = 0.7 %

• phase angle less than 15°

Maximum values ΔU = 4.5 %, Δf = 4.0 % should not be exceeded.

Operation of the machine at reduced speed under 75% of rated speed shouldbe avoided.

NOTE:

Commissioning - 25


5.7. Shut downThe shut-down of the machine depends on the application, but main guidelines are:

1. Reduce the output of the machine to zero.

2. Open the main breaker.

3. Switch the machine excitation off.

4. Stop the engine.

5. Switch the space heaters on if not automatically done by switchgear.

Commissioning - 26


Chapter 6 Operation

6.1. GeneralTo ensure trouble-free running, a machine must be looked after and carefully supervised.

Always before starting up the machine ensure that:

• the bearings are greased with oil to a correct level in accordance with the manufacturer'stechnical specifications and the dimensional drawing

• the cooling system is functioning

• the machine enclosure has been purged and is pressurized if applicable

• no maintenance is ongoing

• personnel and equipment associated with the machine are ready to start up the machine.

For the start-up procedure see Chapter 5.6, Starting.

In case any deviations from expected normal operation are noticed, for example elevatedtemperatures, noise or vibration, shut down the machine and find the reason for the deviations.If necessary, consult the manufacturer of the machine.

The machine may have hot surfaces when running with load.NOTE:

Overloading the machine may cause demagnetization of the permanentmagnets as well as winding damages.

NOTE:

6.2. Normal operating conditionsThe machines manufactured by ABB are individually designed to operate in normal operatingconditions according to the IEC or NEMA standards, customer specifications and internal ABBstandards.

The operation conditions, such as maximum ambient temperature and maximum operating height,are specified in the performance data sheet. The foundation should be free from external vibration,and the surrounding air free of dust, salt and corrosive gases or substances.

Operation - 27


6.3. Protection of synchronous generatorsRecommended protection of synchronous generators:

• Thermal overload in stator winding; I >

• Network short-circuit, I >>

• Stator interwinding short-circuit, differential protection relay

• Stator earth-fault, earth-fault relay

• Over voltage, Over voltage, relay

• Unbalanced load or shorted turns in the same phase, I2/In

• Under excitation and loss of synchromism, under-reactance relay

• Undervoltage and intermittent loss of voltage, undervoltage relay

• Temperature supervision of temperature detectors, PT-100 monitoring

• Inlet cooling air temperature high

• Leakage water detection (if applicable)

• Lubrication of jack-up pumps not in operation (if applicable)

Additional protection:

• Frequency disturbance

• Reverse power

• Diode fault

• Vibration level

6.4. Start-up procedureAlways before starting up the synchronous machine check that:

• the bearings are greased with oil to a correct level in accordance with the manufacturer'stechnical specifications and the dimensional drawing

• No shutdown procedures are in operation.

• Personnel and equipment associated to the machine are ready to start up the machine.

• Cooling water supply to the heat exchangers is in accordance with manufacturer’s technicalspecifications and outline drawing data. See Section 3, Technical Specification and Section4, Mechanical Drawings for details.

• The hydrostatic jacking system for the bearings is switched on. Switch off hydrostatic jackingwhen the machine has reached full speed.

For start-up procedure, see Chapter 5.6, Starting.

Operation - 28


6.4.1. Start interlockingIf the lubricating or cooling systems are provided with pressure or flow monitors, these shouldalso be included in the start interlocking.

A counter for the number of starts and a duty time meter should be included in the system.

6.5. Continuous supervisionThe operating personnel should inspect the synchronous machine at regular intervals. This meansthat they should listen to, touch and smell the synchronous machine and its associated equipmentin order to obtain a feeling for normal operating conditions.

The object of the supervision inspection is to thoroughly familiarize personnel with the equipment.This is essential in order to detect and fix abnormal occurrences in time.

It is therefore recommended that a supervision inspection sheet, preferably like the one in Table6-1, Recommended supervision inspection program is filled in. Data from the supervision inspectionshould be kept for future reference and can be of help in maintenance work, troubleshooting andrepairs.

The difference between supervision and maintenance is rather vague. Normal supervision ofoperation includes logging of operating data such as load, temperatures etc., and the commentsare used as a basis for maintenance and service.

• During the first period of operation (- 200 hours) supervision should be intensive. Bearingand winding temperatures, load, current, cooling, lubrication, and vibration should be checkedfrequently.

• During the following duty period (200 - 1000 hours) a check-up once a day is sufficient. Arecord of supervision inspection should be used and filed. If operation is continuous and stable,the time between inspections may be further extended.

6.6. Shut down proceduresTo stop the synchronous machine:

1. Switch the main breaker open.

2. Switch excitation off.

When the synchronous machine is not in operation, anticondensation heaters must be switchedon to avoid condensation inside the machine.

The cooling water supply must be switched off in order to avoid condensation inside the machine.

For detailed shut down instructions, see Chapter 5.7, Shut down.

Table 6-1. Recommended supervision inspection program

Serial number:Machine type:Date:Point of inspection:

kAStator currentAExcitation current°CBearing temperature, D-end°CBearing temperature, ND-end

Operation - 29


Serial number:Machine type:Date:Point of inspection:

°C°C°CWinding temperature, 1U°CWinding temperature, 1V°CWinding temperature, 1W°CWinding temperature, 2U°CWinding temperature, 2V°CWinding temperature, 2W°CCold air temperature, D-end°CCold air temperature, ND-end°CHot air temperature, D-end°CHot air temperature, ND-endVrms[mm/s]

Vibration level, D-end / axial

Vrms[mm/s]

/vertical

Vrms[mm/s]

/ horizontal /transversal

Vrms[mm/s]

Vibration level, ND-end / axial

Vrms[mm/s]

/ vertical

Vrms[mm/s]

/ horizontal /transversal

m3 / hQuantity of coolant(YES/NO)Water leakagel/min /bar

Oil flow/oil pressure

(YES/NO)Oil leakage(YES/NO)Fault indication

Other observations / comments:

Operation - 30


Chapter 7 Maintenance

7.1. Preventive maintenanceA synchronous machine often forms an important part of a larger installation and if it is supervisedand maintained properly, it will be reliable in operation and guarantee a normal life time.

The purpose of maintenance is therefore:

• To secure that the machine will function reliably without any unforeseen actions orinterventions.

• To estimate and plan service actions in order to minimize down time.

The difference between supervision and maintenance is rather diffuse. Normal supervision ofoperation andmaintenance includes logging of operating data such as load, temperatures, vibrations,as well as verification of the lubrication, and measurement of the insulation resistances.

After commissioning or maintenance, the supervision should be intensive. Temperature of bearingsand windings, load, current, cooling, lubrication and vibration shall be checked frequently.

This chapter presents recommendations regarding maintenance program, and work instructionshow to conduct common maintenance tasks. These instructions and recommendations should beread carefully and be used as a basis when planning the maintenance program. Note that themaintenance recommendations presented in this chapter represent aminimum level of maintenance.By intensifying maintenance and supervision activities, the reliability of the machine and thelong-term availability will increase.

The data obtained during supervision and maintenance is useful for estimating and planningadditional service. In case some of this data indicates something out of the ordinary, thetroubleshooting guides in Chapter 8, Troubleshooting, will aid in locating the reason for thetrouble. ABB recommends the use of experts in the creating maintenance programs, as well as inperforming the actual maintenance and possible troubleshooting.

The ABB After Sales organization is happy to assist in these issues. The ABB After Sales contactinformation can be found in Chapter 9.1.5, After Sales contact information.

An essential part of the preventative maintenance is to have a selection of suitable spare partsavailable. The best way to have access to critical spare parts is to keep them on stock. Ready-madespare part packages can be obtained from the ABB After Sales, see Chapter 9.2, Spare parts.

7.2. Safety precautionsBefore working on any electrical equipment, general electrical safety precautions are to be takeninto account, and local regulations are to be respected in order to prevent personnel injury. Thisshould be made according to instructions of the security personnel.

Personnel performing maintenance on electrical equipment and installations must be highlyqualified. The personnel must be trained in, and familiar with, the specific maintenance proceduresand tests required for rotating electrical machines.

For general safety instructions, see Section 1, Introduction.

Maintenance - 31


7.3. Maintenance programThis chapter presents a recommendedmaintenance program for ABBmachines. This maintenanceprogram is of a general nature, and should be considered as a minimum level of maintenance.Maintenance should be intensified when local conditions are demanding or very high reliabilityis required. It should also be noted that even when following this maintenance program, normalsupervision and observation of the machine's condition is required.

Please note that even though the maintenance programs below have been customized to matchthe machine, it might contain references to accessories not available on all machines.

The maintenance program is based on four levels of maintenance, which rotate according tooperating hours. The amount of work and down time vary, so that level 1 includes mainly quickvisual inspections and level 4 more demandingmeasurements and replacements.More informationabout the spare part packages suitable for this type of maintenance can be found in Chapter 9.2,Spare parts. The recommended maintenance interval can be seen in Table 7-1, Recommendedmaintenance program . The operation hour recommendation in this chapter is given as equivalentoperating hours (Eq. h), that can be counted by the following formula:

Equivalent operating hours (Eq. h) = Actual operating hours + Number of starts * 20

Level 1 (L1)

Level 1 or L1 maintenance consists of visual inspections and light maintenance. The purpose ofthis maintenance is to do a quick check whether problems are beginning to develop before theycause failures and unscheduled maintenance breaks. It gives also suggestions what maintenanceissues must be performed in the next larger overhaul.

The maintenance can be estimated to last approximately 4 - 8 hours, depending on the type andinstallation of the machine and the depth of the inspections. Tools for this maintenance includenormal servicing tools i.e. wrenches and screw drives. The preparations consist of opening theinspection covers. It is recommended that at least the safety package spare parts are availablewhen commencing this maintenance.

The first Level 1 maintenance should be performed after 4 000 equivalent operating hours or sixmonths after commissioning. Subsequently the L1 maintenance should be performed yearlyhalfway between Level 2 maintenance, see Table 7-1, Recommended maintenance program .

Level 2 (L2)

Level 2 or L2 maintenance consists mainly of inspections and tests and small maintenance tasks.The purpose of this maintenance is to find out whether there are problems in the operation of themachine and to do small repairs to ensure uninterrupted operation.

The maintenance can be estimated to last approximately 8 - 16 hours, depending on the type andinstallation of the machine and the amount of servicing to be done. Tools for this maintenanceinclude normal servicing tools, multi meter, torque wrench and insulation resistance tester. Thepreparations consist of opening the inspection covers and bearings if necessary. Spare parts suitablefor this level of maintenance are included in the maintenance package.

Maintenance - 32


The first Level 2 maintenance should be performed after 8 000 equivalent operating hours or oneyear after commissioning. Subsequently the L2 maintenance should be performed yearly or afterevery 8 000 equivalent operating hours, see Table 7-1, Recommended maintenance program .

Level 3 (L3)

Level 3 or L3 maintenance consists of performing extensive inspections, tests and largermaintenance tasks that have come up during L1 and L2 maintenance. The purpose of thismaintenance is to repair encountered problems and replace parts subjected to wear.

The maintenance can be estimated to last approximately 16 - 40 hours, depending on the type andinstallation of the machine and the amount of repairs and replacements to be done. Tools for thismaintenance include the same tools as for L2 and in addition an endoscope and an oscilloscope.The preparations consist of opening the inspection covers, the bearings and the water cooler, ifapplicable. Spare parts suitable for this level of maintenance are included in the maintenancepackage.

The Level 3 maintenance should be performed after every 24 000 equivalent operating hours orat a three to five year interval. When L3 maintenance is conducted it replaces the L1 or L2maintenance otherwise scheduled, and it leaves their rotation unaffected, see Table 7-1,Recommended maintenance program .

Level 4 (L4)

Level 4 or L4 maintenance consists of performing extensive inspections and maintenance tasks.The purpose of this maintenance is to restore the machine into a reliable operating condition.

The maintenance can be estimated to last approximately 40 - 80 hours, depending mostly on thecondition of the machine and the needed reconditioning actions. Tools for this maintenance includethe same tools as for L3, and in addition, the rotor removal equipment. The preparations consistof opening the inspection covers, bearings and water cooler, if applicable, and the removal ofrotor and exciter, if applicable.

The amount of spare parts required for this level of maintenance is difficult to determine. At leastthe maintenance package is recommended, but spare parts included in the capital spare part packagewould ensure a fast and successful execution of this maintenance.

The Level 4 maintenance should be performed after every 80 000 equivalent operating hour.When a L4maintenance is conducted it replaces the L1, L2 or L3maintenance otherwise scheduled,and it leaves their rotation unaffected, see Table 7-1, Recommended maintenance program .

Table 7-1. Recommended maintenance program 1

L4L3L2L1Interval (Eq. h)X4000

X8000X12000

X16000X20000

X24000X28000

(one complete cycle)

Maintenance - 33


L4L3L2L1Interval (Eq. h)X32000

X36000X40000

X44000X48000

X52000X56000

X60000X64000

X68000X72000

X76000X80000

7.3.1. Recommended maintenance programAbbreviation used in maintenance program:

• V = Visual checking

• C = Cleaning

• D = Disassembling and assembling

• R = Reconditioning or replacement

• T = Testing and measurement

Not all options are applicable for all machines.NOTE:

MAINTENANCE INTERVAL

Check / Test

In equivalent operating hours or time period, which ever comesfirst

Maintenanceobject

L4L3L2L180000 Eq. h24000 Eq.h8000 Eq. h4000 Eq. hOverhaul3 - 5 yearsAnnual½ year

7.3.1.1. General construction

Check / TestL4L3L2L1Maintenance ob-ject

Starting, shut down,vibration measure-ment, no-load point

V/TV/TV/TV/TMachine operation

Maintenance - 34



Cracks, rust, align-ment

V/T/DV/TV/TVMounting andfoundation

Rust, leakage, condi-tion

VVVVExterior

Tightness of allfastenings

V/TV/TV/TVFastenings

Fastening, conditionV/TV/TVVAnchor bolts

7.3.1.2. High voltage connection


Wear, fasteningV/T/DV/TV/TVHigh voltagecabling

Oxidation, fasteningV/T/DV/TV/TVHigh voltage con-nections

General conditionVVVVTerminal box ac-cessories, i.e.surge capacitorsand arresters

Condition of cablesentering the ma-

VVVVCable transits

chine and inside themachine

7.3.1.3. Stator and rotor


Fixing, cracks,welds

V/CVVVStator core

Wear, cleanliness,insulation resist-

V/T/CV/T/CV/TVStator winding in-sulation

ance, turn insulationtest, (high voltage

test)Insulation damagesVVVVStator coil over

hangsInsulation damagesVVVVStator coil sup-

portsMovement, tight-

nessVVVVStator slot wedges

Fixing, insulationVVVVStator terminalbars

Maintenance - 35



Tightness, conditionV/TV/TV/TVStator cable ter-minal fasteningsand crimps

Condition of cablesand cable ties

VVVVInstrumentation

Movement, tight-ness, fixing*

V/TV/TV/TVRotor poles

Wear, cleanliness,insulation resist-

V/T/CV/T/CV/TVRotor winding in-sulation

ance, voltage droptest

Movement, bendingVVVVRotor coil sup-ports

MovementVVVVRotor balancingweights

Cracks, corrosion,ultra sound andknocking test

V/TV/TV/TVDamper bars

Cracks, corrosionVVVVShaft and rotorcenter

EqualityV/T/DV/TV/TVAir gapFixing, general con-

ditionV/TV/TVVConnections in ro-

torOperation and gener-

al conditionVVVVEarthing brushes

General condition,insulation resistance

V/TV/TVVRotor shaft insula-tion

* Tightness of possible dovetail connection wedges to be tested

7.3.1.4. Excitation system, control and protection


Cleanliness, opera-tion

V/T/CV/T/CV/T/CVExciter diodebridge

Operation, fixingV/T/CV/T/CV/T/CVExciter semicon-ductors

Fixing, general con-dition

V/T/CV/T/CV/T/CVExcitation connec-tions

Wear, cleanliness,insulation resistance

V/TV/TV/TVExciter windinginsulation

EqualityV/T/DV/T/DV/TVExciter air gap

Maintenance - 36



Operation, settings,stability test

V/TV/TV/TVAVR unit

Operation, connec-tions

V/TV/TV/TVAVR board

Operation, connec-tions

V/TV/TVVPMG

Operation, cleanli-ness

V/TV/TV/TVVoltage trans-former (VT)


V/TV/TVVShort circuit cur-rent transformer

(CT)Operation, cleanli-

nessV/TV/TVVActual value CT


V/TV/TVVMeasurement andprotection CTs

Resistance, insula-tion resistance

V/TV/TV/TVPt-100 elements(stator, coolingair, bearing)

Operation, insula-tion resistance

V/TV/TV/TVAnticondensationheaters

General condition,terminals, wiring

condition

V/TV/TV/TVAuxiliary terminalboxes

General condition,cracks

VVVVmmExciter stator fix-ing

7.3.1.5. Lubrication system and bearings


Fixing, general con-dition

V/TV/TV/TVBearing assembly

General condition,wear

V/T/DV/T/DVVBearing shells

LeakageV/T/DV/T/DVVSeals and gasketsCondition, insula-tion resistance

V/T/DV/T/DV/TVBearing insulation

Leakage, operationV/T/DV/T/DVVLubrication pipingQuality, quantity,

flowV/RV/RV/RV/RLubrication oil

OperationVVVVOil ringOperationV/T/DV/TV/TVOil flow regulator

Cleanliness, leakageV/CV/CV/CVOil tank

Maintenance - 37



OperationV/TV/TV/TVJack-up systemOil temperatureTTTTOil cooler / heater

7.3.1.6. Cooling system


Leakage, operation,pressure test

VVVVHeat exchanger

Operation, conditionVVVVFanCleanliness, corro-

sionV/CV/CV/CVTubes

Cleanliness, opera-tion

V/CV/CV/CVDucts

Leakage, conditionV/CV/CV/CVEnd casesLeakage, conditionV/CV/CV/CVSeals and gasketsGeneral conditionV/CV/CV/CVPlate finsCondition and pro-

fileVVVVVibration dampers

Condition, activityV/CV/CProtective anodesOperationV/TV/TV/TV/TWaterflowregulat-

or

7.4. Maintenance of general constructionTo ensure a long life span for the general construction of the machine, the machine exterior shouldbe kept clean and should periodically be inspected for rust, leaks and other defects. Dirt on themachine exterior exposes the frame to corrosion and can affect the cooling of the machine.

7.4.1. The tightness of fasteningsThe tightness of all fastenings should be verified regularly. Special focus should be given to thegrouting, the anchor bolts and the rotor parts, which must remain correctly tightened at all times.Loose fastening in these parts can lead to sudden and severe damage to the entire machine.

Maintenance - 38


General values for tightening torques are presented in Table 7-2, General tightening torques .

Table 7-2. General tightening torques 2

Tightening forcekN

Tighteningtorque Nm

Tightening forcekN

Tighteningtorque NmProperty class 8.8

µ = 0.16µ = 0.16µ = 0.14µ = 0.14Screw3.33.03.32.7M44.95.55.05.0M57.19.57.59M613241422M821462344M1031803375M124313045120M145920060180M169139095360M 20130660140610M 24170980180900M 2721013002101200M 3030023003102100M 3637030003902800M 3941036004403400M 4256056005805200M 4877090008008300M 56100014000110012000M 64130020000140018000M 72 x 6170027000170024000M 80 x 6220040000220036000M 90 x 6270055000280050000M 100 x 6

The values in Table 7-2, General tightening torques are general, and do notapply to various items, such as diodes, support insulators, bearings, cableterminals or pole fastenings, surge arrester, capacitors, current transformers,rectifier and thyristor bridges, or if some other value is given elsewhere inthis manual or in the mechanical and electrical drawings, see Section 4,Mechanical Drawings and Section 5, Electrical Drawings.

NOTE:

The thread and screw base should be lightly oiled to get a low friction coefficient, µ = 0.14. If oiling is not possible µ =0.16 is used as a friction coefficient.

Maintenance - 39


7.4.2. Vibration and noiseHigh or increasing vibration levels indicate changes in the machine's condition. Normal levelsvary greatly depending on the application, type and foundation of the machine. The vibrationmeasurements and levels are discussed in detail in Chapter 5, Commissioning. Some typicalreasons that might cause high noise or vibration levels are:

• Alignment, see Chapter 3, Installation and alignment

• Air gap, see Chapter 3, Installation and alignment

• Bearing wear or damage, see Section 7, Accessory Information

• Vibration from connected machinery, see Chapter 5, Commissioning

• Loose fastenings or anchor bolts, see Chapter 3, Installation and alignment

• Rotor imbalance

• Coupling

7.4.3. Rotor construction controlParticular attention should be paid to rotor construction, because even small damages in the rotorcan lead to severe damages in the stator. In addition, mechanical problems in the moving partssuch as the rotor, have a tendency to develop faster than in the stationary parts of the machine.

Therefore, rotor construction should be checked yearly, preferably using an endoscope andultrasonic equipment. The condition and tightness of the fastenings should be checked carefully.

7.4.4. Checks during running of the machineDuring the first days of running it is important to keep the machine under close surveillance incase any changes occur in the vibration or temperature levels or there are abnormal sounds.

7.4.4.1. Normal vibration levelsThe following instructions are part of the following two ISO standards:

1. ISO 10816-3:1998Mechanical vibration - Evaluation of machine vibration by measurementson non-rotating parts: Part 3: Industrial machines with nominal power above 15 kW andnominal speeds between 120 r/min and 15 000 r/min when measured in situ.

2. ISO 8528-9:1995 Reciprocating internal combustion engine driven alternating currentgenerating sets: Part 9: Measurement and evaluation of mechanical vibrations.

7.4.4.1.1. Measurement procedures and operational conditions

General procedures described in ISO 10816-1 are used, subject to the recommendations listedbelow.

Measurements are usually made when the rotor and the main bearings have reached their normalsteady-state operating temperatures and the machine running under specified conditions, forexample at rated speed, voltage, flow, pressure and load.

Maintenance - 40


Onmachines with varying speeds or loads, measurements should bemade under all those conditionsat which the machine is expected to operate for prolonged periods. The maximummeasured valueunder these conditions is considered representative of vibration severity.

If the measured vibration exceeds the acceptance criteria and excessive background vibration issuspected, measurements should be made with the machine shut down to determine the degreeof external influence. If the vibration with the machine stationary exceeds 25 % of the valuemeasured when the machine is running, corrective actions may be necessary to reduce the effectof background vibration.

Measurement equipment

The measurement equipment must be capable of measuring broad-band r.m.s vibration with flatresponse over a frequency range of at least 10 Hz to 1000 Hz, in accordance with ISO 2954.Depending on the vibration criteria, this may require measurements of displacement or velocityor combinations of these (see ISO 10816-1). However, for machines with speeds approaching orbelow 600 r/min, the lower limit of the flat response frequency range should not be greater than2 Hz.

Measurement locations

Use a measurement location that is exposed and accessible during normal operation. Make surethat there are no local resonances or amplification so that the final measurements will reasonablyrepresent the vibration of the bearing housing. The locations and directions of vibrationmeasurements should provide adequate sensitivity to the machine´s dynamic forces. Typically,this will require two orthogonal radial measurement locations on each bearing cap or pedestal, asshown in Figure 7-1, Measuring points. Place the transducers at any angular position on thebearing housings or pedestals. Vertical and horizontal directions are usually preferred forhorizontally mounted machines. For vertical or inclined machines, the location that gives themaximum vibration reading, usually in the direction of the elastic axis, is usually used. In somecases it may be recommended to measure the vibration also in the axial direction.When recordingthe results of the measurements, record the specific locations and directions with the actual values.

Figure 7-1 Measuring points

7.4.4.1.2. Evaluation of RIC engine generating sets

The main excitation frequencies of the RIC engine (Reciprocating Internal Combustion) are inthe range of 2 Hz to 300 Hz. However, when considering the overall generating set structure andcomponents, a range of 2 Hz to 1000 Hz is required to evaluate the vibration.

Experience has shown that with a standard design of generating set structure and components,damage would not be expected if vibration levels remain below value 1.

Maintenance - 41


If the vibration levels fall between values 1 and 2, assessment of the generating set structure andcomponents may be required along with an agreement between the generating set manufacturerand the component supplier in order to ensure reliable operation.

In some cases vibration levels can be above value 2 but only if individual special designs ofgenerating set structure and components are applied.

In all cases the generating set manufacturer remains responsible for the compatibility of thegenerating set components (see ISO 8528-5:1993, 15.10).

Table 7-3. Vibration velocity, Vrms

Value 2 [mm/s]Value 1 [mm/s]Declared engine speed [rpm]2820≥1300 but <20002218>720 but <13002015≤720

Additional information

For more details about vibration measuring, see the following International Standards whereapplicable:

• ISO 2954 Mechanical vibration of rotating and reciprocating machinery - Requirements forinstruments for measuring vibration severity

• ISO 5348 Mechanical vibration and shock - Mechanical mounting of accelerometers

• ISO 7919 Mechanical vibration of non-reciprocating machines - Measurements on rotatingshafts and evaluation criteria

• ISO 8528 Reciprocating internal combustion engine driven alternating current generating sets

• ISO 10816 Mechanical vibration - Evaluation of machine vibration by measurements onnon-rotating parts

7.4.4.2. Temperature levelsThe temperatures of the bearings, stator windings and cooling air should be checked when thesynchronous machine is running.

The bearings might not reach a stable temperature until after several (2 - 6) hours, when runningat full speed.

The stator winding temperature depends on the load of the machine. If full load cannot be reachedduring or soon after commissioning, the present load and temperature should be noted and includedin the commissioning report.

The settings for temperature detectors can be found on the main connection diagram in Section5, Electrical Drawings.

The temperature alarm levels for resistance temperature detectors (RTD, Pt-100) should be set aslow as possible in order to detect any rapid abnormalities and trend changes as early as possible.A suitable level can be determined based on the test results, or preferably based on the observedoperating temperatures. It is recommended that the temperature alarm be set 10K (20°F) higherthan the operating temperature of the machine during maximal loading at the highest coolanttemperature.

Maintenance - 42


Recommended procedure for alarm value setting based on site conditions:

1. Initially set the alarm value according to the Main Connection Diagram

2. Run the machine for a minimum of 6 hours at the intended operation point

3. Measure the temperature values related to the alarms and the cooling media. (i.e. the coolingair or the cooling water or cooling oil)

4. Evaluate the maximum temperature variation in the cooling media

5. Consider other possible sources of higher machine temperatures, such as higher load, higherspeed, different power factor etc.

6. Calculate the alarm value as follows: start with the measured temperature at the operationpoint, add in temperature variations in the cooling material as well as those of other possiblesources of higher machine temperatures. In order to obtain the alarm value, add an additional10 degrees C to the previously calculated value

7. Compare the above alarm value to themaximumvalue given in theMain ConnectionDiagram,and choose the lower value as the alarm set value

Do not change the trip limits. If the typical operation point values change,re-set the alarm values.

NOTE:

Example:

Measured stator Pt-100 value at operation point: 107 degrees C. Potential increase in ambient airtemperature: 7 degrees C. Increase in temperature as a result of lower power factor: 4 degrees C.

The calculated alarm set point is: 107 + 7 + 4 + 10 = 128 degrees C. As this value is lower thanthe value in the Main Connection Diagram, it will be used as the alarm set point.

7.5. Maintenance of lubrication system and bearingsThis section covers the most important maintenance tasks for the bearings and the lubricationsystem. Other relevant information about bearing and lubrication can be found in Section 7,Accessory Information and Section 4, Mechanical Drawings.

7.5.1. LubricationThe machines are equipped with sleeve bearings that have a very long service life provided that:

• the lubrication functions continuously

• the oil type and quality are as per ABB recommendations

• the oil change instructions are followed, seeMainDimensionDrawing in Section 4, MechanicalDrawings.

Maintenance - 43


7.5.1.1. Lubrication oil temperatureThe correct lubrication oil temperature is essential in keeping the bearing at the correct operatingtemperature, and in ensuring sufficient lubrication effect and the correct viscosity of the lubricationoil. For machines equipped with oil supply, the poor operation of oil cooler or heater and incorrectoil flow can cause oil temperature problems. For all bearings, the correct oil quality and quantityneed to be checked if temperature problems appear. For more information see Chapter 7.5.1.2,Condition of the lubricant and Chapter 7.5.1.3, Oil qualities.

7.5.1.2. Condition of the lubricantCheck the oil with respect to color, smell, turbidity and deposits in a test bottle.

The following requirements must be fulfilled:

• The oil should be free from debris, and its cleanliness according to ISO 4406 class 18/15, orNAS 1638 class 9.

• The quantity of metal impurities should be less than 100 PPM.

• The oil should be clear or negligibly turbid. The turbidity may not be caused by water.

• Strong acid or burnt smell is not acceptable.

The original viscosity must be maintained within a tolerance of ± 10 - 15%.

The original acid number should not be exceeded by more than 1 mg KOH pergram oil.

An oil check should be performed a few days after the first test run of the machine and subsequentlyas required. If the oil is changed shortly after commissioning, it can be used again after removingwear particles by filtering or centrifuging.

In doubtful cases an oil sample can be sent to a laboratory to determine viscosity, acid number,foaming tendency, etc.

7.5.1.3. Oil qualitiesThe oils listed below are lubricants based on paraffin that have a high viscosity index value (VI> 90) and a particularly low fluid temperature. The oils listed below include the following additives:

• oxidation and rust inhibitor

• anti-foaming agent

• mild EP action, anti-wear additive.

Maintenance - 44


Unless otherwise stated on ABB drawings, the bearings are designed for any of the oil qualitiesdescribed below.

ISO VG 68

Viscosity 68 cSt at 40 °C

Environmentally Benign Oils

Enersyn RC-S 68BP:Summit SH 68Klüber:SHC 626Mobil:Turwada Synth 68Panolin:Corena AS 68Shell:

Mineral Oils

Degol CL 68Aral:Energol CS 68BP:PERFECTO T 68Castrol:MECHANISM LPS 68Chevron:Astron HL 68DEA:TERESSO 68Esso:RENOLIN 207, RENOLIN DTA 68Fuchs:LAMORA HLP 68Klüber:Mobil Oil Heavy MediumMobil:Tellus Öl C 68Shell:Azolla ZS 68Total:

7.5.1.4. Oil change schedule for mineral oilsFor self-lubricated bearings cleaning intervals with oil changes of approximately 4000 operatinghours are recommended and approximately 20000 operating hours for bearings with oil circulationsystems.

Shorter oil change intervals may be necessary in case of frequent start-ups, high oil temperaturesor excessively high contamination due to external influences.

7.5.2. Sleeve bearingsIn normal operating conditions sleeve bearings require little maintenance. To ensure reliableoperation the oil level and the amount of oil leakage should be regularly checked. For more detailedinformation about the bearings see Section 7, Accessory Information.

Maintenance - 45


7.5.2.1. Oil levelThe oil level of a self-lubricated sleeve bearing needs to be checked regularly. The nominal oillevel and maximum and minimum oil level limits can be found either from Section 7, Accessoryinformation or from Section 4, Mechanical Drawings depending on the bearing type. Typicallythe nominal oil level is in the middle of the sight glass, the minimum oil level is the bottom ofthe oil sight glass and the maximum oil level is in the top of the oil sight glass.

If necessary, refill with a suitable lubricant, see Section 4, Mechanical Drawings, Chapter 3.1.1,General and Chapter 7.5.1.3, Oil qualities.

The correct oil level of a flood-lubricated sleeve bearing is the same as for a self-lubricated bearing.In flood-lubricated bearings, the oil sight glass might be exchanged for an oil outlet flange. Drysump type bearings have no oil reservoir inside the bearing and therefore oil sight glass is notneeded.

7.5.2.2. Bearing temperatureThe bearing temperatures are measured by Pt-100 resistance temperature detectors. The normalbearing temperature should be 65 - 85 °C. Since a temperature rise above the alarm limit can becaused either by increased losses in the bearing, or by decreased cooling capacity, it often indicatesa problem somewhere in the machine or in the lubrication system, and should therefore be closelymonitored. The factory set alarm and trip limits are stated in theMain Connection Diagram, seeSection 5, Electrical Drawings.

The reasons for abnormal bearing temperature vary, but for some possible reason see Chapter7.5.1, Lubrication orChapter 8, Troubleshooting. If the temperature rise is followed by an increasein vibration levels, the problem might also be related to the machine's alignment, see Chapter 3,Installation and alignment or to a damage in the bearing shells in which case the bearing needsto be dismantled and checked, see Section 7, Accessory Information.

7.5.3. Oil leakage of sleeve bearingsThe construction of a sleeve bearing is such that it is very difficult to avoid oil leakage completely,and therefore small amounts of leakage should be tolerated.

However, oil leakage can also appear because of reasons other than the bearing design, such asincorrect oil viscosity, over pressure inside the bearing, under pressure outside the bearing, orhigh vibration levels at the bearing.

Maintenance - 46


If excessive oil leakage is noted, please check/verify the following:

• Verify that the oil used is according to specifications

• Re-tighten the bearing housing halves, and the labyrinth seal cover. This is especially important,if the machine has been stopped for a long time

• Measure the vibrations of the leaking bearing in three directions under full load. If the vibrationlevel is high, the bearing housing might "loosen" just enough to permit the oil to wash awaythe sealant between the housing halves

• Open the bearing, clean the surfaces and apply new sealant between the bearing housing halves

• Verify that there is nothing, which might cause low pressure next to the bearing. A shaft orcoupling cover can for instance be designed so that it will cause low pressure near the bearing

• Verify that there is no over pressure inside the bearing. Over pressure may be entering thebearing through the oil outlet piping from the oil lubrication unit. Apply breathers or vents tothe bearing housing as to relieve the over pressure from the bearing

• In case of a flood bearing lubrication system, check that the slope of the oil outlet pipes issufficient.

If excessive oil leakage is found even after all of the above and belowmentioned things have beenchecked and verified, please fill in the form Oil Leakage's at RENK Sleeve Bearings and send itto the after sales and market support department.

7.5.3.1. OilIn order for the bearings to function as expected, the oil has to meet certain criteria like viscosityand cleanliness.

Viscosity

The bearings are designed to run with an oil of a certain viscosity, which is mentioned in thedocumentation provided with the electrical machine. Incorrect viscosity will lead to lubricationfailures, and can damage the bearings, as well as the shaft.

7.5.3.2. Sleeve bearingsThe sleeve bearings used in rotating electrical machines are often 'standard bearings' used in anumber of applications. Therefore, the bearing design in itself is normally not the cause of bearingleakages, and the reason for the leakage should be found elsewhere.

However, the bearing is assembled from several parts, and the joints between the parts can leakdue to faulty assembly or lack of sealing compound.

Bearing housing

The bearing housing consists of an upper and lower half, which are joined together. In addition,labyrinth seals are mounted at the bearing housing entrance of the shaft. This construction is notcompletely hermetic, and therefore very small leakages have to be tolerated.

A tolerable amount of leakage for self-lubricating bearings is such that the bearing does not needa top-up between the oil change intervals.

Maintenance - 47


The oil can leak from the bearing in two ways:

• Past the labyrinth seals

• Through the split line of the bearing housing.

Sealant

In order to prevent the oil from leaking from the bearing through any split lines, sealant is appliedon the split lines. ABB recommends the Hylomar Blue Heavy sealing compound. Curil T or othersimilar compounds can be used as well.

7.5.3.3. Bearing verificationIn case the oil leakage is suspected to originate from the bearing housing itself, the followingsteps can be taken:

1. Re-tighten the bearing housing

This is especially important during the commissioning of the machine, or if the machine hasbeen standing still for a longer period, as the parts may set.

If the bearing housing halves are not in a tight fit in respect to each other, the oil might washaway the sealant from the split line. This in turn will cause oil leakage.

2. Open the bearing housing

The bearing housing can be opened, and new sealant applied on the split lines. Care has tobe taken that no dirt or foreign matter enter the bearing during this procedure. The split lineshave to be completely re-greased before a thin layer of sealant is applied.

7.5.3.4. Oil container and pipingA separate oil container and piping is used only for flood-lubricated bearings.

Oil container

The oil container can be either a separate container, or in some cases, the crankcase of a dieselengine. In both cases, the container has to be well below the bearings, in order for the oil to flowto the container from the bearing.

The oil container should be constructed in such a way that no pressure can enter the oil returnpiping from the container towards the bearing.

Oil piping

The function of the oil return piping is to allow the oil to return to the oil tank with as little offriction as possible. This is normally obtained by choosing a piping diameter of a large enoughdiameter, so that the flow of the oil in the return line does not exceed 0.15 m/s (6 inch/s) basedon the pipe cross section.

Install the oil outlet pipes downwards from the bearings at a minimum angle of 15° whichcorresponds to a slope of 250 - 300 mm/m (3 – 3½ inch/ft).

The assembling of the piping must be performed in such-a-way that above mentioned slope ispresent at all points of the piping.

Maintenance - 48


7.5.3.5. Oil container and piping verificationIn case the oil leakage is suspected to originate from the construction of the oil container or theoil piping, the following steps can be taken:

Pressure in oil container

The atmospheric pressure inside the oil container must be verified. The pressure may not be largerthan the pressure outside the bearing. If this is the case, a breather must be installed to the oilcontainer.

Oil piping

It should be verified that the piping has a sufficient diameter, is not clogged, and that the slope isdownward and sufficient throughout the oil return piping.

7.5.3.6. UseCauses for bearing leakages, apart from being installation-related, some causes are 'use' related.

Oil pressure

The inlet oil pressure for each bearing is calculated according to the desired oil flow, and thereforethe oil pressure should be adjusted accordingly during commissioning. The specific oil pressurevalue for each machine must be verified from the documentation provided with the machine.

Oil temperature

The correct lubrication oil temperature is essential in keeping the bearing at the correct operatingtemperature, in ensuring sufficient lubrication effect, and correct viscosity of the lubrication oil,see Chapter 7.5.1.1, Lubrication oil temperature.

Vibrations

All machines are subjected to, and designed to withstand vibrations. Large vibrations might causethe various parts in the bearing to function different as intended.

Heavy vibrations can cause different phenomena in the oil film between the shaft and the whitemetal, but this will rather seldom lead to oil leakages. Instead, vibrations might cause bearingfailures.

Heavy vibrations can cause the bearing housing parts to set, or to 'loosen up' just enough to allowthe oil to enter the split surface between the upper and the lower bearing housing halves. Thevibrations will cause the bearing housing parts to move in respect of each other. This can causea 'pumping' effect in such a way, that oil will be pumped in and out from the split surface. Thiswill eventually remove the sealant, and cause the bearings to leak.

Over pressure inside the bearing

The bearing housing is not a hermetic compartment, and therefore any over pressure inside thebearing housing will escape the bearing housing via the labyrinth seals. In escaping, the air willbring oil mist with it, thus causing the bearing to leak.

Maintenance - 49


Over pressure inside the bearing is normally caused by other components than the bearing itself.The most common reason for over pressure inside the bearing is over pressure in the oil returnpiping.

Under pressure inside the bearing

Similar to over pressure inside the bearing, under pressure outside the bearing will 'suck' air outfrom inside the bearing, thus bringing oil with it, and causing the bearing to leak oil.

Under pressure inside the bearing is normally not caused by the bearing itself, but by parts outsidethe bearing.

Under pressure near the bearing housing is caused by rotational parts moving the air next to themin such a way that a local under pressure is formed next to the exit of the shaft of the bearing.

7.5.4. Bearing insulation resistance checkThe bearing insulation resistance check is a maintenance operation done primarily in the factoryduring the final assembly and testing. It should also be made during all comprehensive overhaulsof the machine. Good insulation is necessary in order to eliminate the possibility of circulatingbearing currents, which might be induced by shaft voltages. The insulation of the non-drive endbearing cuts the path of the bearing current and thus eliminates the risk of bearing damages dueto bearing currents.

The drive-end shaft of an electrical machine must be earthed, because an unearthed shaft wouldhave an unknown electrical potential compared to the surroundings and would therefore be apotential source of damage. However, to make the testing of the non-drive end bearing insulationeasier, the drive end bearing is also often insulated. This insulation is short-circuited by an earthingcable during normal operation; see Figure 7-2, D-end bearing earthing cable.

Machines with insulated bearings have a sticker indicating the insulatedbearing.

NOTE:

Variable speed drive (VSD) motors that are fed by a converter, have both adrive end and non-drive end bearing insulated and the shaft earthed by brushesat the drive end.

NOTE:

7.5.4.1. ProcedureFor machines with an insulated drive end bearing, the short-circuit earthing cable in the drive endbearing (or earthing brushes on shaft) must be removed prior to commencing the non-drive endbearing insulation resistance test. If the drive end bearing is not insulated, the non-drive endbearing insulation resistance test requires the removal of the drive end bearing, or the removal ofthe bearing housing cover, and lifting of the shaft, so that there is no electrical contact betweenthe shaft and any other part, for example frame or bearing housing. Therefore, when the drive endbearing is insulated, the measurement of the non-drive end bearing should only be conducted byqualified personnel.

Maintenance - 50


Figure 7-2 D-end bearing earthing cable

For all machines any optional shaft earthing brush, rotor earth fault brush and coupling (if it ismade out of conductive material) must be removed. Measure the insulation resistance from theshaft to earth using no more than 100 VDC, see Figure 7-3, The testing of bearing insulationresistance.

Insulation resistance is acceptable if the resistance value is more than 10 kΩ.

Figure 7-3 The testing of bearing insulation resistance

7.5.5. Bearing clearance measurementsThe bearing clearance is measured by opening the upper bearing shell, which makes it possibleto measure the clearance with for example a lead wire at the top and at the sides of the shaft. Themeasuring at the top of the shaft is carried out by placing 40...50 mm pieces of about 1 mm thicklead wire on top of the shaft and on the split surfaces at both sides of the lower bearing shell. Theupper bearing shell is then lowered to rest on the wires and pressed lightly. The thickness of thepressed wires is measured with a micrometer.

The bearing clearance is calculated from the formula:

S = A - [(B1 + B2) ÷ 2]

(mm)bearing clearanceS =where(mm)thickness of lead wire on top of shaftA =(mm)thickness of lead wire on split surfaceB1 =(mm)thickness of lead wire on split surfaceB2 =

The clearance values are given on the dimension drawing or they can be roughly estimated fromthe formula:

S = (n × D)¼ × (D ÷ 14500)

Maintenance - 51


(mm)bearing clearanceS =where(mm)shaft diameter at the bearingD =(r/min)rotating speedn =

7.6. Maintenance of stator and rotor windingThe windings of rotating electrical machines are subjected to electrical, mechanical and thermalstress. The windings and insulation gradually age and deteriorate due to the stress. Therefore, theservice life of the machine often depends on the insulation durability.

Many processes leading to damages can be prevented or at least slowed down with appropriatemaintenance and regular testing. This chapter offers a general description on how to perform basicmaintenance and tests.

In many countries, ABB Service also offers complete servicemaintenance packages, which includecomprehensive testing.

Before conducting any maintenance work on the electrical windings, general electrical safetyprecautions are to be taken and local regulations are to be respected in order to prevent personnelaccidents. See Chapter 7.2, Safety precautions for more information.

Independent test and maintenance instructions can also be found in the following internationalstandards:

1. IEEE Std. 43-2000, IEEE Recommended Practice for Testing Insulation Resistance ofRotating Machines

2. IEEE Std. 432-1992, IEEE Guide for Insulation Maintenance for Rotating ElectricalMachinery (5 hp to Less Than 10 000 hp)

7.6.1. Particular safety instructions for winding maintenanceSome of the hazardous works of the winding maintenance include:

• Handling of hazardous solvents, varnishes, and resins. Hazardous substances are required forcleaning and re-varnishing windings. These substances can be dangerous if inhaled, swallowedor in any contact with skin or other organs. Seek proper medical care if an accident occurs.

• Dealing with flammable solvents and varnishes. Handling and use of these substances shouldalways be by authorized personnel and proper safety procedures must be followed.

• Testing at high voltage (HV). High-voltage tests should only be conducted by authorizedpersonnel and proper safety procedures must be followed.

Dangerous substances used in winding maintenance are:

• white spirit: solvent

• 1.1.1-trichloroethane: solvent

• finishing varnish: solvent and resin

• adhesive resin: epoxy resin

Maintenance - 52


There are special instructions for handling dangerous substances duringmaintenance work. Important handling instructions can also be found onwarning labels of the packing.

NOTE:

Some general safety measures during winding maintenance are as follows:

• Avoid breathing air fumes; ensure proper air circulation at the work site or use respirationmasks.

• Wear safety gear such as glasses, shoes, hard hat and gloves and suitable protective clothingto protect the skin. Protective creams should always be used.

• Spray-varnish equipment, the frame of the machine, and the windings should be earthed duringspray-varnishing.

• Take necessary precautions when working in pits and cramped places.

• Only personnel trained to do high voltage work can carry out a voltage test.

• Do not smoke, eat, or drink at the work site.

For a test record for winding maintenance, see Section 9, Check Lists.

7.6.2. Timing of the maintenanceThere are three main principles for timing the winding maintenance:

• Maintenance of the windings should be arranged according to other machine maintenance.

• Maintenance should be performed only when necessary.

• Important machines should be serviced more often than the less important ones. This alsoapplies to windings that become contaminated rapidly and to heavy drives.

As a rule of thumb, an insulation resistance test should be done once a year.This should suffice for most machines in most operating conditions. Othertests should only be conducted if problems arise.

NOTE:

A maintenance program for the complete machine, including windings, is presented in Chapter7.3, Maintenance program. This maintenance program however, should be adapted to thecustomer's particular circumstances, i.e. servicing of other machines and operating conditions aslong as recommended servicing intervals are not exceeded.

7.6.3. The correct operating temperatureThe correct temperature of the windings is ensured by keeping the exterior surfaces of the machineclean, by seeing to the correct operation of the cooling system and by monitoring the temperatureof the cooling agent. If the cooling agent is too cold, water may condense inside the machine.This can wet the winding and deteriorate the insulation resistance.

7.6.4. Insulation resistance testDuring general maintenance work and before the machine is started up for the first time or afterlong standstill period, the insulation resistance of stator and rotor windings must be measured.

Maintenance - 53


The insulation resistance measurement provides information about the humidity and dirtiness ofthe insulation. Based upon this information, correct cleaning and drying actions can be determined.

For new machines with dry windings, the insulation resistance is very high. The resistance can,however, be extremely low if the machine has been subjected to incorrect transportation andstorage conditions and humidity, or if the machine is operated incorrectly.

Windings should be earthed briefly immediately after measurement in orderto avoid risk of electric shock.

NOTE:

7.6.4.1. Conversion of measured insulation resistance valuesIn order to be able to compare measured insulation resistance values, the values are stated at 40°C. The actual measured value is therefore converted to a corresponding 40 °C value with thehelp of the following diagram (see Figure 7-4, Correlation between the insulation resistance andthe temperature). The use of this diagram should be limited to temperatures fairly near to thestandard value of 40 °C, since large deviations from it could result in errors.

Figure 7-4 Correlation between the insulation resistance and the temperature

R = Insulation resistance value at a specific temperature

R40 = Equivalent insulation resistance at 40 °C

R40 = k x R

Example:

R = 30 MΩ measured at 20 °C

k = 0.25

R40 = 0.25 x 30 = 7.5 MΩ

Table 7-4. Temperature values 3

1101009080706050403020100°C23021219417615814012210486685032°F

in degrees Celsius (°C) and degrees Fahrenheit (°F)

Maintenance - 54


7.6.4.2. General considerationsThe following consideration should be noted, before deciding any actions based upon the insulationresistance tests:

• If the measured value is considered too low the winding must be cleaned and/or dried, seeChapter 7.6.11, Cleaning the windings andChapter 7.6.12, Drying for details. If thesemeasuresare not sufficient, expert help should be acquired.

• Machines, that are suspected to have amoisture problem, should be dried carefully independentof the measured insulation resistance value.

• The insulation resistance value will decrease when the winding temperature rises.

• The resistance is halved for every 10 - 15 K temperature rise.

The insulation resistance indicated in the test report is normally considerablyhigher than the values measured on site.

NOTE:

7.6.4.3. Minimum values for insulation resistanceThe following criteria apply to windings in a normal condition.

Generally, the insulation resistance values for dry windings should exceed the minimum valuessignificantly. Definite values are impossible to give, because resistance varies depending on themachine type and local conditions. In addition, the insulation resistance is affected by the age andusage of the machine. Therefore, the following values can only be considered as guidelines.

The insulation resistance limits, which are given below, are valid at 40 °C, and when the testvoltage has been applied for 1 minute or longer.

1. Rotor

For rotors or synchronous machines: R(1 - 10 min at 40 °C) > 1.5 MΩ

Carbon dust on slip rings and naked copper surfaces lower the insulation resistance values of therotor.

1. Stator

For new stators: R(1 - 10 min at 40 °C) > 1000 MΩ

For used stators: R(1 - 10 min at 40 °C) > 100 MΩ

If the values indicated here are not reached, the reason for the low insulation resistance shouldbe determined. A low insulation resistance value is often caused by excess humidity or dirt, theactual insulation being intact.

Maintenance - 55


7.6.4.4. Stator winding insulation resistance measurementThe insulation resistance is measured using an insulation resistance meter. The test voltage is1000 VDC. The test time is 1 minute, after which the insulation resistance value is recorded. Beforethe insulation resistance test is conducted, check that:

• The secondary connections of the current transformers (CT's), including spare cores are notopen. SeeFigure 7-5, Connection of the stator windings for insulation resistancemeasurements.part a).

• All power supply cables are disconnected.

• The frame of the machine and the stator windings not being tested are earthed.

• Winding temperature is measured.

• All resistance temperature detectors are earthed.

• Winding temperature is measured.

• Possible earthing of voltage transformers (not common) must be removed.

The insulation resistance measuring should be carried out in the terminal box. The test is usuallyperformed to the whole winding as a group, in which case the meter is connected between theframe of the machine and the winding. See part A and part B of Figure 7-5, Connection of thestator windings for insulation resistance measurements. . The frame is earthed and the three phasesof the stator winding remain connected at the neutral point, see part A of Figure 7-5, Connectionof the stator windings for insulation resistance measurements. . In the figure MΩ represents theinsulation resistance tester.

If the measured insulation resistance of the whole winding is lower than specified, and the phasewindings can easily be disconnected from each other, each phase can also be measured separately.This is not possible in all the machines. In this measurement, the tester is connected between theframe of the machine and one of the windings. The frame and the two phases not measured areearthed, see part C of Figure 7-5, Connection of the stator windings for insulation resistancemeasurements. . In the figure MΩ represents the insulation resistance tester.

When phases are measured separately, all star-points of the winding systemmust be removed. If the star-point of the component cannot be removed, asin a typical triphase voltage transformer, the whole component must beremoved.

NOTE:

Maintenance - 56


Figure 7-5 Connection of the stator windings for insulation resistance measurements.

A) Insulation resistance measurement for star connected winding, B) Insulation resistancemeasurement for delta connected winding and C) Insulation resistance measurement for onephase of the winding. MΩ represents insulation resistance meter.

After the insulation resistance measurement the winding phases must beearthed to discharge them.

NOTE:

7.6.4.5. Insulation resistance measurements of the rotor field winding andexcitation machine

The test voltage for the rotor windings and excitation machine is 500 VDC.

When testing the windings of the rotors:

• Disconnect the brush from the slip ring of the earth fault detector if applicable.

• Short circuit the rectifier before measuring.

• Ensure that the stator winding temperature values have been measured. They should be usedas a reference value for the rotor winding temperature.

• Connect the insulation resistance meter between the rotor windings and the shaft of the rotorsas shown inFigure7-6, Connections for insulation resistancemeasurements. . Themeasurementcurrent must not go through the bearings.

• After the insulation resistance measurement, discharge the windings by earthing them.

When testing the stator winding of the excitation machine:

• Disconnect the power supply cables from the voltage source.

• Connect the insulation resistance meter between the stator winding and the frame of themachine as shown in Figure7-6, Connections for insulation resistance measurements. .

Maintenance - 57


SHAFT

2.

1.

Rectifier

Excitation machine

Rotor of synchronous machine

-

+Synch. motor: Thyristors, firing units, protective circuits, starting resistors

MΩ

ROTOR

ROTOR

STATOR

MΩ

Figure 7-6 Connections for insulation resistance measurements.

1. Measurement of windings of the rotors. 2. Measurement of the stator winding of the excitationmachine. MΩ represents the insulation resistance meter

7.6.5. Polarization indexFor the polarization index test the insulation resistance is measured after the voltage has beenapplied for 15 seconds and 1 minute (or 1 minute and 10 minutes). The polarization index test isless dependent on the temperature than the insulation resistance. When the winding temperatureis below 50 °C (122 °F), it may be considered independent of temperature. High temperaturescan cause unpredictable changes in the polarization index, therefore the test should not be usedin temperatures above 50 °C (122 °F).

Dirt and humidity accumulating in the winding normally reduces the insulation resistance, andthe polarization index, as well as their dependence on temperature. Thus, the line in Figure 7-4,Correlation between the insulation resistance and the temperature becomes less steep. Windingswith open creepage distances are very sensitive to the effects of dirt and humidity.

There are several rules for determining the lowest acceptable value with which the machine canbe safely started. For the polarization index (PI), the values usually range between 1 and 4. Valuesclose to 1 indicate that the windings are humid and dirty.

The minimum PI value for class F stator winding is more than 2.

If the insulation resistance of the winding is in the range of several thousandsof MΩ, the polarization index is not a meaningful criterion of the conditionof the insulation, and it can be disregarded.

NOTE:

7.6.6. High voltage testA voltage test is used to check for electrically weak spots in the windings that may lead to insulationfailure during servicing. It is carried out during major inspections, troubleshooting and repairs.DC or AC voltage is used for the high voltage test.

Maintenance - 58


7.6.6.1. High voltage test for stator windingAn AC voltage test is performed using the following test voltages:

• 1.5 × U[V]

where U = rated line-to-line rms voltage of the stator winding [V].

A DC voltage test is performed using the following test voltage:

1.6 x (1.5 x U)

7.6.7. Fault searching methods

7.6.7.1. Voltage drop test (Rotor winding impedance test)Themain rotor field winding can be tested by applying 100-200 VAC over the entire rotor winding.The voltage drop across the total winding and each pole winding is measured. The voltage dropover each pole winding should be the test voltage divided by the number of poles in series. If thevoltage drop measured over the pole windings varies significantly, it may be an indication of apossible turn-to-turn short circuit, connection error or broken lead.

7.6.8. Tan delta-measurementsTan delta -measurements are performed only to the stators whose rated line-to-line rms voltageis more than 4.2 kV.

Tan delta, representing the dielectric and discharge energy losses, is in general measured in stepsof 0.2 U up to the main voltage U. The rate of rise of tan delta as a function of voltage describesthe average partial discharge level both inside and on the surface of the insulation. Thus it isdifficult to determine the condition inside the insulation.

The tan delta test is done using special equipment and should be performed by experiencedpersonnel.

Tan delta measurements cannot be used to estimate the age or predict failureof the insulation. Only regular trend measurements can reveal moreinformation.

NOTE:

7.6.9. Surge comparison testThe surge comparison test detects short circuits or weak points in the turn-to-turn insulation. Steepvoltage pulses are sent to the winding and the oscillations are observed and compared to the resultsof other phases. The test should be done only when it is assumed that there is a weak point in theturn insulation. The test is done using special equipment and should be performed by experiencedpersonnel.

Maintenance - 59


7.6.10. Visual winding inspectionWinding inspections give information on:

• the rate of contamination; presence of dirt and humidity

• radiator condensation and leakage

• stability of bracings, vibration marks, and cracking

• marks of overheating

• marks of movement

• tightness of the slot wedges

• winding overhangs and their supports,

The results of all inspections should be recorded in the check list supplied in Section 9, Checklists.

When examining the contamination, particular attention should be paid to the open creepagesurfaces, as the insulation resistance is easily affected by the dirt accumulating there. There areopen creepage surfaces for example in the brush gear and in connections.

Accumulating dirt blocks the coil gaps and air ducts, and thus diminishes the cooling capacity ofthe machine. As a result, the winding temperature rises, and aging may speed up considerably.

Mechanical strain, vibration, and shocks may cause cracks on the edges of the supports, tyings,and around slot ends. Loose supports and slot wedges are signs of further deterioration. Checkfor abrasion marks and powder near the supports, tyings, and at the slot ends. Complete looseningof the slot wedges and bent coils are serious problems that must be rectified immediately.

Hair cracks and fractures in metal parts such as supporting bolts and squirrel cage windings arealso signs of deterioration, but they take longer to develop into a failure.

Humidity in the winding often causes for example rust on iron, drop marks, dripping, and wettingmarks on dirt layers. Bush-shaped patterns, often charred and left behind by the tracking currents,warn of an approaching failure. In rare cases, the conductors are corroded.

Marks of the electrical effects (apart from tracking current marks), are usually hidden inside theslot and conductor insulations.

Over temperatures that last only for a short period of time can leave marks all over the machine.The following are marks of overheating:

• Copper in the squirrel-cage windings grows darker (darkening may also be due to the gasesin the environment), and it oxidizes.

• Core laminations of the rotor become blue (over 350 °C [662 °F]) if the temperature rises dueto a jam or an exceedingly heavy start.

• There are color differences in the fastening bolts of synchronous machines.

• Insulation may shrink or split (usually over 200 °C [392 °F]), tyings may crack (over 220 °C[428 °F]), and polyester film or fibers may melt (over 250 °C [482 °F]).

• Swelling of the slot insulation is also possible.

Maintenance - 60


Prolonged periods over temperatures cause premature ageing. The insulating materials becomebrittle and darken in the early stages. As a result, the windings split, disintegrate, and fracture.

7.6.10.1. Corrective actions based upon the observationsAccording to the observations the following conclusions can be drawn for necessary actions:

ActionObservationDegree of contamination

- cleaning and drying, if necessary- a lot of dirt, cooling ducts about to be clogged- cleaning and drying, if necessary- conductive dirt, low insulation resistance- drying- humidity, low insulation resistance

Finishing varnish:- cleaning and revarnishing- mat, worn, cracked- removing old varnish and revarnishing- coming off

Supporting parts:- tightening *- loose slot wedges- tightening, strengthening and revarnishing *- vibration marks- strengthening or rewinding *- bent coils

Ageing:- cleaning and revarnishing- darkening, slight embrittlement- rewinding*- embrittlement, loose insulation layer

* = A statement from an expert is needed

7.6.11. Cleaning the windingsIf dirt has accumulated in the open creepage surfaces, it should be removed. This should alwaysbe done when re-varnishing the windings because a new varnish coat will trap any existing dirtbeneath it.

Maintenance - 61


7.6.11.1. Cleaning methodsThe windings can be cleaned using the following methods.

Blowing and vacuuming

Blowing and vacuuming are used if the dirt is dry and can be removed easily. Vacuuming isrecommended, since blowing tends to redistribute the dirt or move it deeper between the insulationlayers.

Wiping

Wiping is used when spray-wash is not possible. Wipe the surfaces that can be reached easilywith a cloth dampened with detergent. In cramped areas of the windings, a special brush may bemore effective. Low insulation resistance is often caused by dirty slip rings and brush gear, sothe creepage surfaces on these components should be carefully cleaned.

Spray wash

A spray wash is carried out with an airless high-pressure spray or a conventional spray. Ahigh-pressure spray is more effective in removing dirt. The detergent used should remove the dirtwithout softening or damaging the insulation. Use large amounts of cleaning agent.

Dip wash

A dip wash can be used if the chosen detergent does not soften or damage the insulation. Sincethe dirt is not removed mechanically, a very effective cleaning and scouring agent must be used.A long dipping time may be required.

Water wash

A water wash involves rinsing with water to prevent the detergents from penetrating into placesfrom where they cannot be removed. Do not wash with water before all other cleaning methodsdescribed above have been tried. A list of suitable detergents can be found in Chapter7.6.11.2, Cleaning agents.

After washing, rinse the windings with pure water several times. It is recommended to use distilledor deionized water for the last rinse

Dry the windings after the water wash.

7.6.11.2. Cleaning agentsSome features of recommended detergents are described in Table 7-5, Features of the detergentsfor the winding.

Before any cleaning agent is used, its damaging effect on the old winding surface should bechecked. A suitable test can be performed as follows:

1. Rub the tested surface for five minutes using a cloth and the cleaning agent. Make sure thatthe surface remains completely wet during this time.

2. Try to remove the varnishing using for example your thumb nail.

3. For comparison, try to remove the varnishing on a dry part of the surface

Maintenance - 62


If the surface layer feels soft or can be removed easily, the cleaning agent is too strong.

For minimal environmental loading, water or water-detergent mixtures should be used whenpossible. If the dirt contains water soluble agents, water must be used.

Substances that improve the cleaning power should be added to the water to dissolve grease-containing dirt. Make sure that a detergent does not leave electrically conductive residues on thesurfaces.

Water soluble solvents, such as acetone and isopropyl alcohol, can also be used to improve thecleaning effect. Note that such solvents increase the flammability of the mixture.

If organic solvents must be used, cleaning agents based on aliphatic hydrocarbons arerecommended. Several manufacturers of cleaning solvent mixtures are presently developing suchhalogen-free cleaning agents to replace the chlorinated solvent mixtures used in the past.

White spirit is themost common organic solvent. It is a good solvent for greases but quite inefficientfor pitch-like dirt on the windings (produced by coal and burning residues of diesel oil andhumidity). White spirit is also flammable (flash point 30 - 40 °C [86 - 104 °F]). The cleaningcapacity of white spirit can be improved by adding 1.1.1-trichlorethane to the solvent. However,the use of chlorinated solvents is no longer recommended.

Table 7-5. Features of the detergents for the winding

Empty: Doesnot resist thesolvent

212333Siliconerubber

VAR-NISH ORRESIN 33333333Epoxy

and poly-ester resin

1: Poor resist-ance of solvent

2: Satisfactoryresistance ofsolvent

dissolvingor soften-ing effect 22223333Redfinish-

ing var-nish(epoxy, al-kyd) 3: Good resist-

ance of solventEmpty: Doesnot clean

1333221 - 31Pitcheddieselgrime,fats, oils

DIRT dis-solving

or redu-cing ef-fect

1: Removes dirtpoorly

2: Cleans reas-onably

33Salts2222212Greasy

woodpulp3: Cleans well

3333322Greasycoaldust

32113132Normaldust

2002001001000200400Allowed concentra-tion in air,

ppm or cm3/m3

Maintenance - 63


EXPLANA-TIONS

11 Not re-commen-ded

Incombust-ible

Not re-commen-ded

111111Incombust-ible

Incombust-ible

Class of flammableliquids

1:1(volume)

1:20(volume)

Proportion / Consist-ency

Whitespirit

1.1.1-tri-chloroeth-ane

XyleneAcetoneWhitespirit140/200

Isopropyl-enealco-hol

Water(hot)

+ deter-gent

Water(hot)

Detergent

+ 1.1.1-trichloro-ethane

7.6.12. DryingThe windings must be dried:

• after washing (especially a water wash and rinse)

• if they have become humid in use or during a standstill.

Drying should always be started with an external blower or warm air. Other means should beattempted, only if blower and warm air do not suffice.

During drying, the rate of temperature rise of the winding should not exceed 5 K (9 °F) per hour,and the final temperature should not exceed 105 °C (220 °F). A sudden temperature rise or a toohigh final temperature can cause steam to be formed in the cavities of the windings, which in turncan destroy the windings. During the drying process, the temperature should be monitoredperiodically, and the insulation resistance should be measured at regular intervals.

A very wet machine should be dismantled and the windings dried in an oven. Every part shouldbe checked. If the machine is not very wet, the winding can be dried by passing a current throughit.

If the winding is dried by passing a current through it, the source of electricity can be for examplea welding machine or a similar device.

Direct current or alternate current can be used. The current must not exceed25 % of the nominal current, which is indicated on the rating plate on themachine. The winding temperature should also be continuously monitored.

NOTE:

When drying in an oven, the temperature rise and the maximum temperature should be monitoredcarefully. The oven temperature should be around 90 °C (194 °F) for 12 to 16 hours and then 105°C (220 °F) for six to eight hours. These times can vary, and the correct time should be monitoredwith an insulation resistance test.

Effective drying is achieved with the right balance of heat and ventilation. The air circulationinside the machine should be as effective as possible.

Drying in an oven with good ventilation is the most effective technique. Unfortunately, this is notusually possible at the machine's operating site. Therefore, either hot-air-blow or heating thewindings with current should be used. Adequate fresh-air circulation is essential, whatever heatingmethod is used.

Maintenance - 64


An insulation resistance test should be performed after drying the windings. When drying isstarted, the insulation resistance decreases due to the temperature rise. As the drying continues,however, the insulation resistance increases until it reaches a stable value.

7.6.13. Partial dischargesPartial discharges (PD) are a normal phenomenon in medium and high voltage rotating electricalmachines (rated voltage several kV). The thickness of insulation in rotating electrical machinesis relatively small compared to the voltage stress, which leads to a relatively high electrical fieldstrength. The breakdown strength of gas (air) can be locally exceeded on the surface of theinsulation and on small gas filled cavities that can be left inside the insulation layers and materials.This can lead to some sparking in the gas, known as partial discharge. As a result of PD, insulationmaterials that are able to withstand partial discharge should be used. A mineral called mica iswidely used in the insulation systems of rotating electrical machines.

A very high partial discharge level can be a symptom of a problem in insulation, for examplecontamination of the end winding surfaces made of electrically conductive or hydroscopic material.

When running at very high voltages, semiconducting taping should be used in addition toconductive taping. The semiconductive tape is applied on coil ends as an extension to the conductivetaping. The length of the conductive taping area depends on the rated voltage of the machine. Thesemiconductive taping should be applied so that it is in contact with the end of the conductivetaping. This prevents sparking on the end of the conductive taping by affecting the surface potential(voltage) distribution on the surface of the coil.

At low rated voltages the conductive and semiconductive tapings are not needed.

When conductive taping is used, part of it is visible near the slot ends of the stator core. Theconductive tape is black. The semiconductive tape is usually not visible because it is covered bythe red surface tape of the coil.

In some cases it is possible that patterns caused by partial discharge can be seen on the coilsurfaces. If this happens, the conductive tape used on the slot sections of the coils, or the redsurface tape used on coil ends, has been partly eroded by partial discharge. This can be causedby:

1. inadequate contact between conductive and semiconductive taping

2. inadequate contact of the conductive tape outside the stator slot to ground (stator core)

3. grounded metallic parts too close to the coil surface (for example a dislocated stator coreend support plate "finger")

The eroded area is typically gray or white and dusty. The netlike polyester fabric of the conductiveor surface tape is also usually visible.

Normally there is no need for immediate actions. Even though the conductive tape or surface tapeis eroded, the mica insulation of the coil is not damaged, and the reliability of the insulation innot affected. The local erosion is limited to conductive or surface tape.

It is recommended that the eroded conductive tape is replaced within a few years, for exampleduring a scheduled service stop, to reduce the discharges. If the eroded tape is not replaced anddischarges are intensive, the insulation might in the long run be affected or the metal parts corrodeddue to the ozone created by the discharges. In case of 1) or 2) (see list above) the eroded conductivetaping can be repaired with semiconductive or conductive paint. In case 3) the metallic part shouldbe bent back to the right position and any sharp edges should be rounded. Detailed repairinstructions are available from ABB by request, for contact information see Chapter 9.1.5, AfterSales contact information.

Maintenance - 65


7.6.14. Varnishing of the windingsA finishing varnish is a varnish or a resin coat that is sprayed or brushed on the insulation. It is aprotective layer that seals the windings, improves tracking resistance and makes cleaning easier.In new machines a finishing varnish treatment is optional.

The finishing varnish can crack or peel after a long operating time. Re-varnishing is necessarywhen:

• the old finishing varnish flakes, cracks or peels off.

• the surface of the winding is rough (dirt sticks to it easily).

The windings should be cleaned carefully before a new coat of varnish is applied, so that no dirtwill be left under the new coat. Old finishing varnish that can come off easily should be removedbefore re-varnishing.

Varnish is usually applied with a spray (one or two coats suffices). If the windings are still warmafter drying, wait until the temperature of the windings is below 40 °C (104 °F). Apply the varnishbetween the coils and other parts that are not easily reached. Avoid thick coats of varnish as theydry slowly. Rotating parts should be left to dry for at least 24 hours at room temperature beforebringing them into use. Solvent fumes from the varnishes are generally poisonous and flammable,so safety at work should be taken into account.

7.6.15. Other maintenance operationsUsually, ABBmade winding are trouble-free and in addition to periodical monitoring they requireonly occasional cleaning and drying as described above. If extraordinary circumstances occur andother maintenance is required, it is best to acquire professional help. The ABB After Salesorganization is happy to assist in questions regarding maintenance of electrical machine windings,for contact information see Chapter 9, After sales and spare parts.

7.7. Maintenance related to electrical performance, excitation, control, andprotection

The electrical performance of a synchronous machine is mostly defined by the condition of therotor and stator windings and the operation of the excitation system. The main machine windingmaintenance is described inChapter 7.6, Maintenance of stator and rotor winding. In this chapterthe focus is on the maintenance of the excitation system and the control and protection systems.

7.7.1. Exciter insulation resistance measurementThe insulation resistance in the exciter can be tested with the winding insulation resistance test.The procedure is described in detail in Chapter 7.6, Maintenance of stator and rotor winding.The test voltage for the exciter stator should be 500 VDC and the test should be performed in theterminal box after the cables have been disconnected. The connection is shown in Figure 7-7,Connection for exciter stator insulation resistance test .

The resistance of the exciter rotor is usually measured jointly with the rotor of the main machine,see Chapter 7.6.4.5, Insulation resistance measurements of the rotor field winding and excitationmachine. The resistance of the exciter rotor can also be measured separately, but this requiresspecial arrangements.

Maintenance - 66


Figure 7-7 Connection for exciter stator insulation resistance test

(MΩ represents insulation resistance tester)

7.7.2. Protection tripsThe synchronous machine needs to be protected with alarms and trips in case of abnormal runningconditions, both electrical and mechanical. Some of these protections can be reset and the machinerestarted directly as the fault is located.

Alarms or trips in the following protections should be further investigated:

• Diode fault protection, see Chapter 7.7.6, Diode fault.

• High temperature in bearing, seeChapter 7.5, Maintenance of lubrication system and bearings.

• High temperature in winding or in cooling air, see Chapter 7.6, Maintenance of stator androtor winding and Chapter 7.7, Maintenance related to electrical performance, excitation,control, and protection.

• Over current, current unbalance, bus bar voltage.

• Vibration protection, see Chapter 5, Commissioning.

7.7.3. Maintenance of Automatic Voltage Regulator (AVR)When the systems is at a standstill the screwed terminals should be checked for tightness. Dustycooling flanges should also be cleaned.

Unit must not be opened. Defective unit should be sent to the manufacturer for repairing. In thatcase the following information should be attached:

• the serial number of the AVR

• the serial number of the generator in which the AVR is installed

• the problem noticed in the AVR

• which operation condition is concerned

• which operation mode is concerned.

Maintenance - 67


7.7.4. Pt-100 resistance temperature detectorsPt-100 resistance temperature detectors are an essential part of the machine's monitoring andprotection system. They are used to measure the temperature of the windings, bearings and thecooling air. The Pt-100 detectors use a fine platinum filament for measuring the temperature. Theyshould be handled carefully as they can be damaged for example by incorrect handling or excessivevibration.

The following symptoms might suggest a problem in a Pt-100-detector:

• Infinite or zero resistance over the detector.

• Disappearance of measurement signal during or after start up.

• A significantly different resistance value one of the detectors.

If a Pt-100 failure is suspected, always confirm the finding from the connection box. This can bedone by measuring the resistance over the detector. Register the findings in the Pt-100 FailureInspection Protocol found in Section 9. For the correct measuring current and resistance valuesat different temperatures see Section 7, Accessory Information and the appropriate Pt-100 detector.

There are two possible remedies for a Pt-100 detector damage. If there are operational sparedetectors remaining in the stator winding, they can be taken into use. If all the working factoryassembled detectors are in use a new detector can be retrofitted in the winding end. Contact ABBfor further information.

7.7.4.1. Pt-100 temperature detector retrofitting

Introduction

The temperature detectors for form wound stator windings are typically installed between the twocoils of the stator slot. Because of this the detectors are not replaceable, and additional identicaltemperature detectors cannot be added. For more information, see Section 7, Accessory Informationand the Pt-100 elements.

However, in some cases additional temperature detectors of a different design may be installed.The instructions below describe how to add extra detectors to the stator winding head area.

Installation place

The copper lead in the stator winding is fully insulated through the whole coil, and the surfacepotential of the coil inside the stator core is very close to the potential of the stator core. However,the surface potential of the stator winding increases rapidly after the coil exits the stator core, andtherefore it is important to try to place the temperature detector as close to the stator core aspossible.

If the nominal voltage of the stator winding is 1 kV or more, the temperature detector shouldpreferably be installed on the coil, which is electrically close to the stator winding star point. Thisis particularly important when the nominal voltage of the stator windings is 10 kV or more.

Installation

Before installing a temperature detector, verify that it functions properly.

Temperature detectors, for example the Pt-100, should be installed near thestator core, see Figure 7-8, Temperature detector installation place.

NOTE:

Maintenance - 68


Figure 7-8 Temperature detector installation place

To install the temperature detector:

1. Choose a coil of preferred phase. The coil should be electrically close to the stator windingstar point.

2. If the nominal stator voltage is more than 4.2. kV, scratch the red and/or brown surface tapeslightly so that the black conductive tape ends, or the grey semiconductive tape start pointis visible.

3. Paint a small area, approximately 30 mm with conductive paint. The overlap of the paintwith the conducive tape should be at least 5 mm, see Figure 7-9, Conductive painting.

Figure 7-9 Conductive painting

Contact with the winding

A good contact between the coil and the detector is essential when the temperature detector isplaced on the stator winding, as the purpose of the temperature detector is to monitor thetemperature of the coil, not the surrounding air. Therefore the temperature detector should beplaced as close to the coil surface as possible.

To install the temperature detector:

1. Place the temperature detector on the coil using silicone padding 10 mm around the detector.

2. Cover the temperature detector with polyester felt with a total thickness of approximately 6mm. This ensures that the detector is not cooled by the ambient airflow.

3. Bind and impregnate the felt using glass or Terylene tape and air-dry polyester or epoxyresin, see Figure 7-10, Temperature detector and cover should be impregnated and boundedtightly.

Maintenance - 69


Figure 7-10 Temperature detector and cover should be impregnated and bounded tightly

7.7.5. Insulation resistance measurement for auxiliariesTo ensure correct operation of the machines protections and other auxiliaries, their condition canbe determined by an insulation resistance test. The procedure is described in detail in Chapter7.6, Maintenance of stator and rotor winding. The test voltage for the space heater should be 500VDC and for other auxiliaries 100 VDC. The insulation resistance measurement for Pt-100detectors is not recommended.

7.7.6. Diode faultIf a diode in the rotating rectifier fails, the generator must be tripped. To determine and locate afaulty diode:

1. Open the covers at the non-drive end of the machine and measure the insulation resistancewith an ohm-meter over one of the diodes.

2. If diode failure is detected, disconnect all diodes and test them separately to locate the faultydiode.

Do not open the service covers or end shields unless it is certain that themachine is isolated from its driving source.

NOTE:

To replace faulty diodes:

1. Open the service doors at N-end shield of the machine.

2. Disconnect the wires connected to the diodes and exciter winding connection cables. Seethe diode bridge/thyristor bridge drawing in Section 5, Electrical Drawings.

3. Check the condition of the diodes by measuring the resistance over a diode in both directions.

4. Replace the damaged diode(s).

5. Clean the contact surfaces, and apply electric joint compound.

6. Fasten the diode(s). Bind the connection leads of the diodes as on original assembly.

7. Check fastening and locking of all rectifier bridge components.

8. Make sure that no tools etc. are inside the machine and close the service covers.

Maintenance - 70


Figure 7-11 LND SD600N22P diode in the rectifier bridge

After replacing the diodes, the condition of the diodes can be checked by comparing no-loadexcitation current to commissioning values. A diode failure results as a significant increase inexcitation current.

7.8. Maintenance related to thermal performance and cooling systemAn increase in the machine's temperature is usually caused by:

• a decline in the effect of the cooling system

or

• excessive amounts of heat produced by the machine.

If the machine temperature exceeds normal values, determine which of these two causes isresponsible for the increase in the temperature. Excessive heat production might be caused forexample by a winding problem or by network unbalance and in these cases corrective actions onthe cooling system would be ineffective or harmful.

7.8.1. Maintenance instructions for air-to-water heat exchangerIf the temperature detectors show normal temperature, and the leakage detectors indicate no leaks,no additional supervision is required for the cooling system. If the coolers have to be cleaned, seeinstructions in Chapter 7.8.1.3, Cleaning.

If the winding or cooling air temperature detectors show an abnormal temperature, the coolingsystem has to be checked. Either of the following two reasons could be causing the problem inthe cooling system:

• incorrect operation of the heat exchanger

Ensure that the operation of the heat exchanger is uninterrupted and correct. The heat exchangershould be cleaned periodically and it should be checked for leakage. For more informationsee Chapter 7.8.1.3, Cleaning. Check also that air flow through the heat exchanger isuninterrupted.

• problems in the primary cooling circuit

Maintenance - 71


Ensure good air circulation in the primary cooling circuit inside the machine. The machineinterior should be cleaned and checked during overhauls or if problems arise.

Other possible causes for poor heat exchanger performance include elevated ambient temperature,coolant water flow or temperature abnormality.

In addition, a lubrication or bearing malfunction might lead to high bearing temperatures. Aseemingly high temperature might also be caused by a problem in the temperature measurementsystem, see Chapter 7.7.4, Pt-100 resistance temperature detectors.

7.8.1.1. InstallationThe cooler can be installed both for vertical and horizontal air flow. The cooler is a standarddesign with a crossflow water circuitry. The direction of air flow is not relevant.

7.8.1.2. Starting upThe supply and return pipes should be flushed before they are connected to the cooling element.

If the pipework is pressure tested with the cooling element connected, the test pressure shouldnot exceed the value specified on the rating plate of the cooling element.

During pressure testing and when starting up the system, back off the vent plugs to release anyair in the pipework. Venting should be carried out frequently during the initial period of operation.

Adjust the water flow to the required level. If the flow is too low, the cooling capacity of the coilwill be impaired and deposits may occur on the insides of the tubes. If the flow is too high, thecooling capacity will be increased, but erosion may occur on the insides of the tubes.

7.8.1.3. CleaningEven if air and water filters are used, some fouling of the cooling surface and the tube wall willoccur. This fouling reduces the cooling capacity. The cooling element should therefore be cleanedat regular intervals, to be determined from case to case, depending on the quality of the air andwater. During the initial period of operation, the coil should be inspected frequently.

To clean the water side:

1. Drain the cooling element thoroughly.

2. Remove the cooling element from the system if this will make cleaning easier.

3. Remove the chambers and mark up the location of the chamber to ensure correct mounting.

4. Clean the inside of the tubes using a brush. Flush with water.

5. Remove the old gasket and clean the inside of the chamber.

6. A new self-adhesive gasket (QLKZ-01) can be stuck on the chamber. The gasket is made ofEPDM cellular rubber 9x3 mm. (neoprene rubber).

7. Mount the chamber to a correct location.

Maintenance - 72


8. Tighten the screw joint with a torque wrench.

- Torque: 80 Nm

- (8 kmp or 708 Lbf.in)

To clean the air side:

1. Blow the cooling element clean with compressed air or flush it carefully with water.

2. Add detergent to the water if the surface is coated with fatty deposits.

7.8.1.4. Risk of freezingIf a water-filled coil is not in service and the temperature drops below freezing point, the finnedtubes may burst and the chambers may be deformed.

If there is a risk of freezing, all water should be drained from the coil by removing the drain andbent plugs.

7.8.1.5. Inoperative coilsA cooling element that is not in use should be completely drained of water to prevent damage dueto corrosion or freezing. This is particularly important if coils with cupro-nickel tubes are used,since this material is particularly susceptible to corrosion caused by deposits.

Do not refit the drain plugs after the cooling element has been drained, since the shut-off valvesmay leak and fill the coil with water.

To ensure that the cooling element is completely drained, remove one water box.

When the cooler is installed for vertical air flow, the bottom row of tubes cannot be completelydrained. In order to avoid the risk of freezing when the cooling element is out of operation, oneof the chambers should always be removed.

7.8.2. Disassembly and remounting of cooling system

The cooling unit should be disassembled following these steps:

• Turn off the cooling water circulation in the cooling unit.

• Disconnect the water pipes from the heat exchanger.

• Empty the heat exchanger.

Maintenance - 73


Figure 7-12 Water pipe connections in heat exhanger

• Disconnect the earthing wire.

Figure 7-13 Earthing connection between the machine and the cooling unit

• Disconnect the leakage water sensors from the cooling unit.

Maintenance - 74


Figure 7-14 Leakage water sensor connections

• Unscrew the fixing bolts.

Maintenance - 75


Figure 7-15 Fixing bolt

• Lift and remove the cooling unit.

The cooling unit should be reinstalled following these steps:

• Check the condition of the seal and replace if needed.

• Lower the cooling unit on the top of the machine.

• Attach the bolts and tighten them. Correct tightening torques can be found in Chapter7.4.1,The tightness of fastenings.

• Connect the earthing wire.

Maintenance - 76


Figure 7-16 Mounting of the cooling unit

Part list: 1 Screw; 2 Washer; 3 Nut; 4 Seal

Remember to insert the washer between the machine and the coolingunit fastening brackets as shown in the figure 7-16, Mounting of thecooling unit . The cooling unit should rest on the washers instead ofthe seal. Incorrect installationmight damage the seal causing unwantedleakages.

NOTE:

• Connect the leakage water sensors.

• Connect the water pipes to the heat exchanger.

• Turn on the cooling water circulation in the cooling unit.

Maintenance - 77


Chapter 8 Troubleshooting

This chapter is intended as a help in the event of an operational failure with an ABB deliveredmachine. The troubleshooting charts given below can aid in locating and repairing mechanical,electrical and thermal problems, and problems associated with the lubrication system. The checksand corrective actions mentioned should always be conducted by qualified personnel. If in anydoubt, the After Sales of ABB should be contacted for more information or technical assistanceregarding troubleshooting and maintenance.

8.1. Mechanical performance

Vibr

atio

n

Noise

Corrective actionx x Check lubricant quality and quantity and lubrication

system functionx x Damaged bearing parts Check bearing condition and replace bearing partsx x Faulty bearing assembly Open and readjust the bearing

x x Faulty cooling fan(s) Imbalanced or damaged fan(s) Check and repair cooling fan(s)

x Inspect and repair cooling systemx Inspect and repair excitation system

x x Check machine alignmentx x Rebalance rotor

x x Check rotor wedges, poles etcx, repair and rebalance rotor

x x Check the balance of connected machinery and coupling type

x x Check alignment and coupling function and typex x Check coupling functionx Reinforce foundation as per ABB instructions

x Check main machine and excitation machine windingsx x Check that network balance fulfils requirements x x Check bearing pedestal alignment

x Check and clean machine interior, dry windingsx x Measure and adjust airgap

Malfunctioning excitation system

Mechanical performanceTroubleshooting

Lubrication malfunction

Malfunctioning cooling system

Bearing malfunction

Experienced malfunction

Possible cause

Machine misalignmentRotor or shaft imbalance

Loose parts in rotor

Vibration coming from connected machinery

Axial load coming from connected machineryFaulty or incorrectly assembled couplingInsufficient foundation strengthMain machine or excitation machine winding faultExcessive network unbalanceBearing misalignmentForeign material, moisture or dirt inside the machineAirgap not uniform

Troubleshooting - 78


8.2. Lubrication system and bearings

8.2.1. Lubrication system and sleeve bearings

High

bea

ring

tem

pera

ture

Oil le

aks

Oil in

side t

he m

achi

neBe

arin

g no

ise o

r vib

ratio

nVi

sibly

poor

oil q

ualit

y

Corrective actionx x x Oil flow malfunction Check oil pump, oil reduction valve and oil filterx Oil viscosity too high Check oil temperature and oil typex x x x Check ABB oil recommendationsx Check lubrication system and adjust oil temperaturex x Oil quality is reduced Incorrect oil change period Clean bearing and change oilx x x x Excessive axial load Faulty coupling or mounting Check coupling, mounting and alignmentx x x Realign machinex x Verify correct bearing assemblage and adjustments

x x x Oil impurities Change oil, check bearing condition, replace bearing shells

x x Bearing currents Restore bearing insulation, replace bearing shellsx x Complete bearing failure Replace bearing partsx x Normal wearing Replace bearing shellsx x Operating speed too low Check the operating speed range of bearingx Faulty instrumentation Faulty temperature detector Check bearing temperature measurement system

x Replace bearing sealsx Oil flow too high Faulty regulator settings Check and correct oil flowx Problem in oil return flow Faulty oil piping Check oil return pipe inclinationx External vacuum Rotating equipment nearby Check pressure levels, relocate rotating equipmentx x Internal over pressure Pressure compensation failure Remove cause for internal over pressure

x Replace or repair machine sealx Check pipeline connections and oil filter tightness

x x Clean bearing and check seal condition

Damaged or worn-out bearing seals

Damaged machine sealFaulty assembled or maintained lubrication pipingForeign matter inside the bearing

Troubleshooting

Unsuitable oil qualityOil inlet temperature too high

Machine misalignment

Lubrication system and sleeve bearings with oil supply

Damaged bearing shells


Possible causeInsufficient lubrication

Incorrectly assembled bearing



8.3. Thermal performance

8.3.1. Thermal performance, air-to-water cooling system

High

win

ding

te

mpe

ratu

reHi

gh co

olin

g air

te

mpe

ratu

reW

ater

leak

age

alarm

Corrective actionx x Damaged cooling fan Replace fan

x x Fan rotating in wrong direction Change shaft mounted fan or correct external blower motor operation

x x Dirty machine interior Clean machine parts and air gapsx x Coolant pipes are blocked Open cooler and clean pipesx x Faulty coolant pump Check and repair the pumpx x Faulty flow regulator settings Check and adjust coolant flowx x x Leaking cooler header Replace the cooler headerx x Air inside the cooler Bleed the cooler through bleeder screwx x Emergency cooling hatch open Close emergency cooling hatch tightlyx x Adjust cooling water temperaturex Overload Control system setting Check machine controls, eliminate overloadx Check that network balance fulfils requirements x x x Check measurements, sensors and wiringx Let the machine cool down before restartingx Check main machine and excitation machine windings

Cooling water inlet temperature too high

TroubleshootingThermal performance, air-to-water cooling system

Main machine or excitation machine winding fault


Possible causeLow primary cooling circuit performance

Low secondary cooling circuit performance

Faulty instrumentation or measurement systemToo many starts

Network unbalance

For high bearing temperature, see Table 8.2, Lubrication system and bearings.NOTE:



8.4. Electrical performance

8.4.1. Electrical performance and excitation system of generators

Lost

excit

atio

nIn

crea

se in

excit

atio

n cu

rrent

Malfu

nctio

n du

ring

star

t-up

Perfo

rman

ce d

eviat

ion

Oper

atio

n no

t adj

usta

ble

Faul

ty p

arall

el op

erat

ion

Corrective actionx x Abnormal speed Faulty speed control Check speed control of operating machine

x x Check that network balance fulfils requirements x Check speed control of operating machine

x x Faulty settings Check excitation panel relay and voltage regulator settingx x Faulty wiring Check excitation panel control cubicle and generator

x x Demagnetised excitation magnet See main connection diagram to restore permanent magnet excitation

x x x x Check transformer winding insulation resistance and connectionsx x x x x Check transformer winding insulation resistance and connectionsx x Check transformer winding insulation resistance and connectionsx x Check operation of short circuit excitation system

x Check main machine winding and insulation resistancesx x Check exciter winding and insulation resistancesx x x x x Check connection and condition of rectifier componentsx x x x Check electrical connections in excitation system

x xExcitation equipment fault Excitation panel equipment Check and replace excitation panel equipment

x x x x x x Check and adjust voltage regulator settings

xBad AVR tuning parameters Voltage oscillation, poor response Check AVR tuning (PID parameters)

x x x x x x Check and replace voltage regulatorx x x x x x Check AVR wiring and connections

x Check AVR conditionx x x Check connections and condition of voltage reference

x xCheck actual value measurement system and electrical connections

Troubleshooting

Network phase unbalanceSpeed variation of operating machine

Defective voltage transformer

Electrical performance and excitation system of generators with transformer excitationExperienced malfunction

Possible Cause

Field application failure

Defective parallel operation transformerDefective current transformerShort circuit excitation system failureMain generator winding faultExcitation system winding faultFaulty rotating rectifier Faulty wiring in excitation system

Faulty AVR settings

No actual value information for AVR

Defective AVRFaulty AVR wiring or incorrect connectionsPower factor variation over permitted valuesFaulty external voltage reference system



Chapter 9 After sales and spare parts

9.1. After SalesThe After Sales support for rotating electrical machines manufactured by ABB and Strömberg,has been located in Helsinki, Finland since 1889.

9.1.1. Site ServicesThe Site Services department provides:

• Installation and commissioning

• Maintenance and inspections

• Troubleshooting and service

• Upgrading and modifications.

9.1.2. Spare PartsThe Spare Parts department:

• Co-ordinates spare parts packages delivered with the machine

• Sells genuine spare parts after the machines have been delivered.

For spare part packages, see Chapter 9.2, Spare parts.

9.1.3. Support and WarrantiesThe Support department:

• Handles warranty issues under warranty period based on written claims

• Makes warranty determination

• Decides about corrective actions

• Provides technical support.

9.1.4. Support for Service CentersThe Service Center Support provides help for authorized Service Centers in questions concerningthe mechanical construction as well as in electromagnetic and insulation technology issues.

9.1.5. After Sales contact informationContact the After Sales department by:

+358 (0)10 22 11Phone 7 am - 5 pm (GMT+2):

After sales and spare parts - 82


+358 (0)10 22 2710024-Hour Support Line:+358 (0)10 22 22544Fax:[email protected] for spare parts:[email protected] for site services:[email protected] for warranties and technical support:

If available, please add the serial number of the machine (seven digits, startingwith 45#####) to your e-mail for reference information.

NOTE:

9.2. Spare parts

9.2.1. General spare part considerationsThe machines manufactured by ABB are designed and manufactured to provide reliable andtrouble-free operation for decades. This requires, however, that the machines are properlymaintained and operated. This maintenance includes changing of parts subjected to normal wear.

There is always an inevitable amount of uncertainty related to wearing. The wear rates of theseparts vary greatly according to application, environment and particular conditions. Therefore, thecondition of these parts should be checked regularly and a sufficient amount of spare parts shouldbe kept in stock. These spares help to minimize down time if the need appears. The extent of thestock should be decided based upon the importance of the application, the availability of theparticular spare part and the expertise of the local maintenance personnel.

9.2.2. Periodic part replacementThere is always mechanical wearing when two moving surfaces are in contact with each other.In electrical machines most of the mechanical wearing occurs between the rotating shaft andstationary parts. The bearing parts, such as bearing shells and oil rings in sleeve bearings, willeventually wear out and need to be replaced, even if correct lubrication is maintained. Otherwearing parts include seals that are in constant contact with the rotating shaft, and the brushes,brush gears and slip rings of the slip ring unit.

The parts mentioned abovemake an extensive, but not a complete, list of the mechanically wearingparts. These parts have an estimated life span, but as mentioned earlier, their actual durability canvary significantly. For this reason, at least these parts should be kept in stock. It should also benoted that the replacement of these parts, due to normal wearing, is not covered by the warranty.

9.2.3. Need of spare partsOther types of wear occur due to elevated temperatures, electrical disturbances and chemicalreactions. The wear of the diodes in the rectifier bridge is usually related to abnormal electricaloperating conditions. It is usually a slow process, but it is strongly dependent on the operationconditions of the machines and system disturbances.

Air filters, which protect the machine interior from contamination, become themselves saturatedwith air impurities and need to be replaced to ensure the correct operation of the cooling unit, andthe continuous protection of sensitive machine parts.

The electrical windings of the ABB machines have good protection against wear, but only ifcorrect maintenance and operating conditions are followed. The correct operating temperaturemust not be exceeded and the windings must be cleaned from dirt regularly. The winding can alsobe subjected to accelerated wear due to a number of electrical disturbances.



There are stator winding Pt-100 temperature detectors located inside the stator core slots. Thesedetectors cannot be replaced. Therefore, spare Pt-100 detectors are ready installed in the statorwinding. These spare detectors can be taken into use if the primary detector fails. If also the sparedetector should fail, the possible corrective action is to add Pt-100 detectors into the stator windingend. Contact ABB for further information.

9.2.4. Selection of the most suitable spare part packageABB provides three level of ready made spare part packages. The personnel best informed of themachine's operational conditions should select the most suitable package based on criticality ofthe application and on the financial risk related to the duration of downtime and loss of production.

Safety parts for commissioning and to ensure usability

• These are the most essential spare parts that you should have always available.

Maintenance parts for troubleshooting and scheduled maintenance

• These parts should be available while doing medium term maintenance.

• These parts also enable fast recovery in case of failure in the most of the accessories.

Capital spare parts to reduce repair time in case of serious damage

• These spare parts are recommended when the machine is a part of an essential processes.

• These spare parts enable fast recovery even in case of a serious damage.

9.2.5. Typical recommended spare parts in different setsBelow is presented a general recommendation of the typical spare parts for different packages.To receive a quotation for specific parts for a specific machine, please contact the ABB Aftersales organization.

Please note that even though ABB has customized the spare part sets to match the machine, theymight contain references to accessories not found on all machines.



9.2.5.1. Safety package

Main machine

AmountSpare part1 pc.Automatic voltage regulator (AVR)3 pcs.Rectifier diodes1 pc.VaristorSetAir filters1 pc.Pt-100 for cooling air

Lubrication system and bearings

AmountSpare part1 pc.Bearing RTD2 pcs.Bearing labyrinth seal1 pc.Bearing shell, for D-end and ND-end1 pc.Bearing oil ring

9.2.5.2. Maintenance package

Main machine

AmountSpare part1 pc.Safety package (without AVR)1 pc.AVR with board1 pc.Voltage transformer3 pcs.Short circuit current transformers1 pc.Actual value current transformer3 pcs.Stator current measurement transformers1 pc.Space heater

9.2.5.3. Capital spare parts

AmountSpare part1 pc.Exciter rotor1 pc.Exciter stator1 pc.Rectifier bridge2 pcs.Rotor pole1 pc.Rotor (complete)1 pc.Stator with frame



AmountSpare part1 pc.Water cooler element

9.2.6. Order informationTo ensure fast and correct spare part order and delivery, our After sales personnel should beprovided with the serial number of the machine in question. The serial number can be found eitheron the rating plate fixed to the machine frame, or stamped on the machine frame, and is also givenin this manual.

In addition, provide specific and detailed information about the parts ordered (in most cases thisinformation can be found in Section 7, Accessory Information. The contact information of ABB'sAfter sales organization can be found in Chapter 9, After sales and spare parts.



Chapter 10 Disposal and recycling instructions

10.1. IntroductionABB Oy is committed to its environmental policy. We strive continuously to make our productsenvironmentally more sound by applying results obtained in recyclability and life cycle analyses.Products, manufacturing process as well as logistics have been designed taking into account theenvironmental aspects. Our environmental management system, certified to ISO 14001, is thetool for carrying out our environmental policy.

These instructions are trendsetting and it is on the customer’s responsibility to ensure that localthe legislation is followed.

10.2. Average material contentThematerial content (average percentage of the mass) which have been used in the manufacturingthe electrical machine is the following:

Fabricated steel frame synchronousmachines (AMGandAMZ)81 %Steel13 %Copper2 %Cast iron3 %Insulation materials1 %Other

10.3. Recycling of material required for transportAfter receiving the machine into the site, the package and the transportation locking have to beremoved.

• The transportation locking is made of steel and can be recycled.

• The package is made of wood and can be burned.

• The sea trial package to some countries like Australia have special requirements, and is madeof impregnated wood that must be recycled according to local instructions.

• The plastic material around the machine can be recycled.

• The rust protection material covering the machined surfaces can be removed with petrolbasedsolvent detergents and the cleaning rags are hazardous waste which have to be handledaccording to the local instructions.

10.4. Recycling of the complete machine

10.4.1. Dismantling of the machineBecause of the weight of the components, the personwho does the dismantling has to have adequateskills to handle heavy components to prevent dangerous situations.

Disposal and recycling instructions - 87


10.4.2. Frame, bearing housing, covers and fanThese parts are made of structural steel, which can be recycled according to local instructions.All the auxiliary equipment, cabling as well as bearings have to be removed before melting thematerial.

10.4.3. Components with electrical insulationThe stator and the rotor are the main components, which include electrical insulation materials.There are, however, auxiliary components which are constructed of similar materials and whichare hence dealt with in the same manner. This includes various insulators used in the terminalbox, excitation machine, voltage and current transformers, power cables, instrumentation wires,surge arrestors and capacitors. Some of these components are used only in synchronous machinesand some are used only in very limited number of machines.

All these components are in an inert stage once the manufacturing of the machine has beencompleted. Some components, in particular the stator and the rotor, contain a considerable amountof copper which can be separated in a proper heat treatment process where the organic bindermaterials of the electrical insulation are gasified. To ensure a proper burning of the fumes theoven shall include a suitable after burning unit. The following conditions are recommended forthe heat treatment and for the after burning to minimize the emissions from the process:

Heat treatment380…420 °C (716…788 °F)Temperature:After receiving 90 % of the target temperature the object shall stay aminimum of five hours at this temperature

Duration:

After burning of the binder fumes850…920 °C (1562…1688 °F)Temperature:The binder fumes shall stay a minimum of three seconds in the burningchamber

Flow rate:

The emission consists mainly of O2-, CO-, CO2-, NOx-, CxHy-gases andmicroscopic particles. It is on the user’s responsibility to ensure that the processcomplies with the local legislation.

NOTE:

The heat treatment process and the maintenance of the heat treatmentequipment require special care in order to avoid any risk for fire hazards orexplosions. Due to various installations used for the purpose it is not possiblefor ABB Oy to give detailed instructions of the heat treatment process or themaintenance of the heat treatment equipment and these aspects must be takencare by the customer.

NOTE:

10.4.4. Permanent magnetsIf the permanent magnet synchronous machine is melted down as a whole, nothing needs to bedone to the permanent magnets.

If the machine is dismantled for more thorough recycling and if the rotor must be transported afterit, it is recommended that the permanent magnets are demagnetized. The demagnetization is doneby heating the rotor in the oven until the permanent magnets reach a temperature of 300 °C (572°F).



Magnetic stray fields, caused by an open or disassembled permanent magnetsynchronous machine or by a separate rotor of such a machine, may disturbor damage other electrical or electromagnetic equipment and components,such as cardiac pacemakers, credit cards and equivalent.

NOTE:

10.4.5. Hazardous wasteThe oil from the lubrication system is a hazardous waste and has to be handled according to localinstructions.

10.4.6. Landfill wasteAll insulation material can be handled as a landfill waste.

