Draft Tap changer Spec 0039, Rev 2 - Indian Railways · 2019-02-04 · technical specification for no-32 tap changer for 25 kv ac conventional locomotives specification no. elrs/spec/gr/0039

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Issued on Nov. 2009 Dec.2018

ELRS/SPEC/GR/0039(Rev’1’2)

Prepared by Checked by Issued by

lR;eso t;rs

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

TECHNICAL SPECIFICATION

FOR

NO-32 TAP CHANGER

FOR 25 KV AC CONVENTIONAL LOCOMOTIVES

SPECIFICATION NO. ELRS/SPEC/GR/0039 (Rev. ‘2’)

December, 2018

Approved by Signature

PEDSE

ELECTRICAL DIRECTORATE

RESEARCH, DESIGNS & STANDARD ORGANISATION MANAK NAGAR, LUCKNOW-226 011

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Status of Revision

S.N. Date of Revision Page No. Revision Reasons for Revision

1. - All 0 First Issue

2. 23.11.2009 Top cover, 2,7,8,9,10,11,14,15

1 Revision 1

3. 28.12.2018 Top cover, 4,19 2 Revision 2

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Index

Forward

1.0 Scope

2.0 Service Conditions

3.0 Submission of Tender Quotation

4.0 Technical Documents and Drawing to be supplied as a Part of the Contract

5.0 Guarantee

6.0 Technical Specification

7.0 Standards

8.0 Drawings

9.0 Tests

Annexure - A : Three (3) Sheets

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FOREWORD

(A) Specification No ELRS/SPEC/GR/0039(Rev 0) of Dec 2005 was prepared by RDSO for indigenous development of NO-32 tap changer (Ganz type) initiated by Railway Board. The equipment has been indigenized by M/s AAL, Noida under MOU with M/s Ganz, Hungry.

(B) Presently, CLW is procuring NO-32 tap changer for WAG-7/WAP-4 locomotives as per CLW specification No. CLW/ES/T-28 or RDSO’s specification No. ELRS/SPEC/GR/0039(Rev 0). RDSO’s specification No. ELRS/SPEC/GR/0039 (Rev 1). Based on the request of CLW vide their letter No. ELDD/3252/AKM dt. 05.10.2009 Eastern Railway Workshop, Kanchrapara’s letter no ERWK/EPD/KED/6/SD/1914 dated 03.12.2018, it is considered to use a common specification amend functional test requirement for Ganz type NO-32 tap changer and accordingly RDSO’s existing specification ELRS/SPEC/GR/0039(Rev 1 2) has been prepared.

(C) The equipment to be manufactured indigenously and supplied as per revised RDSO specification No. ELRS/SPEC/GR/0039(Rev 1 2) will be same as supplied by M/s BTIL and AAL to IR so far and it will be completely interchangeable and comparable in all respects with the N-32 tap changers procured by CLW/IR for BG AC 25 KV Electric Locomotives.

1.0 SCOPE

1.1 This specification covers the manufacture & supply of single phase High voltage ON-LOAD Tap Changer to be used in conjunction with locomotive transformers in 25KV ac locomotives to regulate the voltage up and down on the high voltage side of the transformer through 32 working taps. The Tap Changer must be capable of operation in service in the voltage range of 17.5 to 30 KV and for high switching frequencies. The tap changer will be directly mounted on the transformers. Typical connection diagram of Tap Changer with Locomotive Transformer is represented in DRG. NO. CLW/ES/SK-1/T-28.

1.2 Scope of supply of this tap changer shall essentially comprise of the following Items:

(i) Tap Changer complete with circuit breaker (C.G.R.)

(ii) Air Servomotor with Aux. Cam switches.

(iii) Pneumatically operated oil pump, oil filter, oil flow indicator with complete with 3-Way oil cock and nipples for pipe connection.

(iv) Oil level gauge and breather with silicagel.

(v) Transition Resistances (RGR) with support.

(vi) Relays for interlocking and synchronism during multiple operation of electric locomotives (Relay Q46, Q52, and Q49).

(vii) Air control panel (ZSM) complete with pressure reducing valve, Air pressure gauge

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with cock, 3-Way air cock, electro pneumatic valve for supplying compressed air to oil pump and auxiliary switch, programme switch for change-over from Master Controller to push Buttons switches and mechanically interlocked handle for manual drive.

(viii) Tap Changer Notch Indicator.

(ix) Selsyn Notch Indicators (2 Nos.) for Driver’s Desk ,one selsyn transformer and selsyn Transmitter mounted on the servo-motor. Angular displacement between two taps is 10º.

(x) Total Notch operation recorder/counter.

(xi) Manual Hand drive complete consisting of –

(a) One gear box.

(b) One disc scale position indicator

(c) One Cardon shaft

(d) One crank

(e) One coupling flange

(xii) The tap changer & Air servomotor with aux. Cam switch box cover shall be finished with light gray colour paint (Colour No. 638 of IS 5-1994).

(xiii) Two free wheeling silicon diodes for electro magnetic valve (progression & regression).

(xiv) In addition to the above accessories, the following components/Hardware will also be supplied along with each tap changer suitably for installation and commissioning.

(a) Gasket

(b) Lock Pin

(c) RGR – CGR support complete.

(d) Insulation plate

(e) Silicagel

(f) Cork grain

(g) Hex, Screw – M8x30

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(h) Bel. washer dia 9 x 18

(i) Hex nut dia 0.8 x m8

(j) Plain washer dia 8.4 /18x2

(k) Instruction slip

(xv) 4 number coupling nut and nipple (As per M/s Ganz Drg. No. 383740002 and 383741 for Electro Magnetic tap changer )

(xvi) Installation manual

(xvii) Maintenance manual

Note : A list of spare parts required for periodical maintenance may be indicated with periodicity along with their offer. The consumable & other spares requirement shall be of the existing design as far as possible to minimize stocking problems in the sheds.

2.0 SERVICE CONDITIONS

2.1 The tap changer and other accessories covered in this specification shall be suitable for service in ambient temperatures varying from 0°C to 55°C with maximum relative humidity of 100% in altitudes upto 1000 metres above mean see level and in dusty atmospheric conditions.

2.2 All the components of the tap changer and other accessories shall satisfactorily withstand the vibration and buffing shocks that are encountered during normal working of the locomotives, Values shall be as indicated below:-

Maximum vertical acceleration - 1.0 g

Maximum Longitudinal acceleration due to shocks. - 3.0 g

Maximum transverse acceleration (‘O’ being acceleration due to gravity) - 0.5 g

3.0 SUBMISSION OF TENDER QUOTATION

All tender quotations must be submitted in quadruplicate. The tenderer shall inter-alia furnish the following along with their quotation.

(i) Full technical particulars of the offer as described in para 6.2 and Annexure ‘A’ in four copies.

(ii) Technical literature describing construction, principle of operation, maintenance instructions with illustrations etc. to have a general idea of the equipment offered in six copies.

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(iii) Detailed dimensional drawings indicating overall and mounting dimensions including full details to clearly demonstrate its suitability for transformer arrangement of auxiliary contact arrangements etc. in 6 copies.

(iv) The tenders shall furnish break-up of prices as below:- (As per para 1.2)

a. Tap changer complete with the transition resistance (RGR), Servo-motor, ZSM panel and Transition contactors.

b. Selsyn Transmitter, Tap changer Notch position Indicators (2 Nos.)

c. Manual Drive.

d. Relays 3 Nos. (Q49, Q52 & Q46)

4.0 TECHNICAL DOCUMENTS & DRAWINGS TO BE SUPPLIED BY THE SUPPLIER AS A PART OF THE CONTRACT.

4.1 The following documents and drawings shall have to be supplied by the supplier as a part of the contract.

4.1.1 Type Test reports or certificate.

This shall be supplied in standard ‘A4’ size (210x297 mm) of sheet punched holes for filing suitably enclosed in a cover. Type test shall be witnessed by an officer representing the INDIAN RAILWAY. Ten copies of the type test report shall be supplied duly signed by representative of both the parties.

4.1.2 Routine Test Certificate.

This shall be supplied in standard ‘A4’ size of sheets with punched holes for filing. Routine test certificate shall be supplied in six copies alongwith each tap changer.

4.1.3 Drawings.

The supplier shall submit two sets of detailed dimensional drawings indicating mounting arrangement, arrangement of auxiliary contacts with in two months from the date of placement of the contract for RDSO’s approval. One set of approved drawings will be returned to the supplier duly approved with changes, if any, considered necessary.

The supplier shall submit six (6) sets of such drawings taking into account any changes / modifications indicated in a approved drawings. A compete set of reproducible tracings for all these drawings shall also be supplied.

4.1.4 Maintenance Instructions.

The contractor shall prepare maintenance instruction booklets in standard ‘A4’ size of papers with punched holes for filling suitably enclosed in a cover. These booklets shall include detailed maintenance instructions of the complete tap changer with necessary

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illustrations, besides maintenance instructions these books shall also include brief description of the equipment, principle of operation and list of recommended spares. These instruction booklets shall have to be supplied by the contractor as a part of the contract and number of copies to be supplied shall be as follows:-

No. of tap changer to be supplied against the particular contract divided by 2+10 copies. Supply of these instruction booklet shall be completed within the delivery period of the equipment specified in the contract.

5.0 GUARANTEE

5.1 The supplier shall give a guarantee of clear 30 months after the date of despatch/shipping or 24 months from the date of commissioning of the locomotive by user Railway whichever earlier.

5.2 Identification Marks.

Manufacturer shall stencil/engrave/emboss/imprint permanent identification marks indicating their monogram and year of manufacture at a conspicuous place.

5.3 The supplier shall send their representative for investigation of the cause of damage/failure, if any, of the equipment to the place (any where on the Indian Railways) where the equipment is in service. Any modification, improvement or repair considered necessary shall be done by the supplier free of cost after consulting with RDSO. This shall be done within shortest possible time.

6.0 TECHNICAL SPECIFICATION

The tap changer covered under this specification is required for on-load tap changing on the high voltage side of the locomotive transformer. The technical particulars of the transformer are given below.

6.1 Transformer --

6.1.1 Type : 5400kVA

6.1.2 Manufacturer : M/s BHEL, Bhopal; M/s NGEF, Banglore; M/s CGL, Mumbai; M/s Hind Rectifier, Mumbai; M/s EMCO, Mumbai; M/s Steaslit, Baddi

6.1.3 Line Voltage

Rated Voltage : 25 KV

Maximum Voltage : 27.5 KV

Max Voltage for short duration : 30 KV

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Minimum rated value for guaranteed value of traction service.

: 22.5 KV

Minimum Voltage at which traction is possible

: 19 KV

Minimum voltage for functioning of Auxiliaries

: 17.5 KV

6.1.4 Frequency

Rated frequency : 50 Hz

Frequency fluctuation : 48.5 to 51.5 C/s

6.1.5 Percentage Impedance

Percentage impedance of the transformer with Two secondary windings short circuited

: ±10% Tolerance as per IEC-60310

Percentage impedance with only auxiliary Winding short circuited

: 3 to 5%

6.2 Tap Changer

6.2.1 Technical Particulars :

Rated voltage : 25 KV

Rated current : 400 Amp

Frequency : 50 Hz.

Frequency fluctuation : 48.5 to 51.5 Hz

Number of taps : 32

Number of circuit breaker (CGR) : 3

Maximum service voltage : 27.5 KV

Method of drive. : Electro pneumatically operated through servo motor

Rotation angle per tap on the Breaker (CGR) drive shaft

: 90º

Run through time for 32 taps : 9 - 13 secs.

Run time per tap(approx) : 0.28 - 0.40 secs.

Resistance value of RGR transition resistance

: 1.61 ohms ± 10%

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6.2.2 Short Circuit Current Rating.

Contact rollers : 10 KA (Peak)

Circuit breaker contacts : 7.5 KA (Peak)

6.2.3 Selector

Number of tap segments : 33

Even numbered taps : 17

Odd number taps : 16

Diameter of the terminal pin of the transformer side.

: 12 mm

Number of selector rollers (Cadmium copper)

: 2

Maximum permissible temperature of transformer oil Spring loaded potential contact :

: 90ºC At 16th notch

6.2.4 Circuit Breaker

The material of the contact tips should preferably be of cadmium copper

6.2.5 Air Motor

Rated average air pressure : 3 Kg/cm2

Operating air Pressure : 2.5 to 3.5 Kg/cm2

Rotation Angle of the crank shaft per tap : 180º

Rotation Angle of the fast moving Aux. Switch Drum per tap

: 90º

Rotation Angle of the slow moving Aux switch drum per tap

: 10º

Nominal voltage of the control valve : 110 V

Operating voltage range : 77 to 137.5 volts

6.2.6 Auxiliary Cam Type Switch

Contact Gap : 4.5mm +0 –2

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Contact Pressure : 160-260 gm.

Maximum permissible current --

110 V - resistive load : 0.9A

110 V - inductive load : 0.6A

Number of Auxiliary Switches : 35 Nos. for BTIL design & 42 Nos. for Ganz design

6.2.7 Oil filtration Unit

Operating Pressure : 3Kg/cm2

6.2.8 The tap changer shall be supplied without oil. A 3-way valve shall be provided for draining the tap changer oil when necessary

6.2.9.1 The selector housing of the tap changer shall be provided with suitable safety valves to release excess pressure developed in side the housing either in case of accidental short circuit or in the normal service conditions of the locomotives described in para 2.0 of this specification.

6.2.9.2 The contact plate shall be able to withstand a static pressure of twice the setting value of the safety valve.

6.2.10 Clause 1.2 lists out the accessories which form part of the tap changer and shall be supplied along with the tap changer.

6.2.11 The auxiliary contact arrangement shall be in accordance with the requirement of locomotive circuitry and is shown in Drg. Nos. CLW/ES/SK-6/T-28 &. CLW/ES/SK-7/T-28 for WAG7 and WAP4 Locomotives respectively. If any change in the auxiliary contact arrangement is required at a later stage arising out of the change in the locomotive circuitry the same shall be incorporated by the supplier on receipt of advice from RDSO/CLW.

6.2.12 The housing that contains the air motor unit. The auxiliary cam switches etc. shall be mounted on the right hand side of the selector housing and the oil filtration unit shall be mounted on the left hand side of the selector housing. A typical arrangement for reference purpose is shown in SKEL/4701(REV0) or CLW/ES/SK-10/T-28.

6.2.13 The tap changer shall be supplied in fully assembled condition with all the internal connections made. Hardware, items duly cadmium plated required for all the external electric / pneumatic connection & mounting the parts supplied separately shall also be supplied by the supplier.

6.2.14 The tap changer shall be suitable for direct mounting on the transformer on its flange. The selectors and circuit breaker together to form a complete unit and shall be

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mechanically coupled and interchangeable. The tenderer shall note this point that “It shall be possible to mount the tap changer on the transformer without any modification on it. Also the tap connecting pins etc. shall be exactly of the same design & suit the existing transformer tap connections (12 mm) SKEL/4701(REV0) or CLW/ES/SK-10/T-28.

6.2.15 The circuit breaker shall be provided with magnetic blow out coil, and supported on two insulated columns. It shall be mounted clear of the oil filled selector casing.

6.2.16 The transformer and the selector shall be separated by oil tight seals so that during overhauls only the oil from the selector casing need be drained and no entry of oil to the selector casing from the transformer tank is possible.

6.2.17 Depending on the design the tap changer a circulating pump and a filter for the selector oil may also be provided to keep the oil clean over long periods of operation by extracting metallic particles which may break off from the selector contacts mechanism. In such a design an oil flow indicator shall be connected to indicate proper functioning of the oil filtration unit. The capacity of the oil pump shall be adequate to pump at least 40 litres of oil/hour.

6.2.18 The air motor shall be Electro-pneumatically controlled with four cylinder reciprocating type which will drive the tap changer and cam type switches. This shall operate at a service pressure between 2.5 and 3.5 Kg/cm2. A pressure reducing valve, three way cock and pressure gauge to read between 0 and 10 Kg/cm2 shall be connected in series with the motor. It is advisable to couple a two-pole auxiliary switch with this three way cock so that when the latter is closed for manual operation, the control leads for operating solenoid are automatically switched off. The electrically operated pneumatic control unit shall be connected to the air motor by two way connections and one return line. Depending on the pulses received, this unit will allow the motor to run in steps or continuously in either direction.

6.2.19 The air motor and its control unit shall virtually be unaffected by temperature changes, moist air, shock and vibration.

6.2.20 The mechanism for movement of the tap changer shall be such, as to ensure notch-to-notch movement & shall not permit any over-shooting with in close tolerances.

6.2.21 Arrangement shall also be available for manual operation of the tap changer. In the event of failure of tap changer electrical control, it shall be possible to efficiently operate the tap changer manually by this drive. The change over shall be possible by isolating the air supply to the servomotor by an interlocking mechanism achieved by the manual drive handle.

6.2.22 When moving from one tap to another, the transition resistances are introduced and cut out to avoid surges and smooth operation of the locomotive. The exact cam movement, opening & closing of breakers, introduction of transition resistance, may be furnished by the supplier.

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7. STANDARDS

7.1 The tap changer and its other accessories shall be built generally to comply with the international electro-technical commission’s latest publication No. 60077-1 (latest).

7.2 Special Condition.

Once a prototype is approved the contractor shall not change their source of supply or sub-contactor for purchased components and sub-assemblies without RDSO’s approval.

7.3 RDSO reserve the right to procure materials only from the ISO Certified firms.

7.4 Repeat the type test after every five years.

8.0 DRAWINGS

8.1 The following drawings are enclosed with this specification.

1. CLW Drawing No. CLW/ES/SK-1/T-28 showing the connections of the Tap Changer in the high voltage circuit of the transformer

2. CLW Drawing No. CLW/ES/SK-3/T-28 showing the arrangement of Auxiliary Contacts



5. CLW Drawing No. CLW/ES/SK-6/T-28 showing the arrangement of contacts of tap changer in WAG7 locomotive (Notching Chart)

In this notching chart drawing interlock 59-60 has been shown closed in between 0-10, however it should close in between 0-5 notch as per present schematic diagram of locomotives(Ref. CLW’s letter No. ELDD/3252/AKM dt. 05.10.09) and manufacturers shall comply the above.

6. CLW Drawing No. CLW/ES/SK-7/T-28 showing the arrangement of contacts of tap changer in WAP4 locomotive(Notching Chart)

In this notching chart drawing interlock 59-60 has been shown closed in between 0-10, however it should close in between 0-5 notch as per present schematic diagram of locomotives(Ref. CLW’s letter No. ELDD/3252/AKM dt. 05.10.09) and manufacturers shall comply the above.

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7. RDSO Drawing No. SKEL/4700 (Rev0) / CLW Drawing No. CLW/ES/SK-8/T-28 showing the arrangement of the layout of tap changer Control Panel (ZSM)

8. CLW Drawing No. CLW/ES/SK-9/T-28 showing the arrangement for Notch Indicator of “Gr”

9. RDSO Drawing No. SKEL/4701(Rev0)/ CLW Drawing No. CLW/ES/SK-10/T-28 showing the assembly, mounting and dimensional details of the tap changer

9.0 TESTS

9.1 Tests are classified as type and routine tests. Type tests shall be carried out on one tap changer. Routine test shall be carried out on each and every unit. Test program for the tap changer and air motor, air panel (ZSM), oil pump are given below:-

9.2 Tests of Tap Changers

Type Test Routine Tests

9.2.1 Visual Inspection Y Y

9.2.2 Tightness test of the case (before assembly)

To be made at ambient temperature with petroleum with 300 g/sq. cm. Pressure during 48 hours.

Y Y

9.2.3 Record of mechanical Characteristics

(a) Contactors (C.G.R.)

Measurement of contact pressure (When New) and breaking distance:-

(i) Contact opening

(ii) Contact sag.

(iii) Contact pressure (new contacts)

(7.8 Kg ± 15%)

Y Y

(b) Selector

Measurement of roller contacts pressure (12.4 Kg. ± 15%)

Y Y

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(c) Auxiliary Contacts.

Measurement of contact pressure & Breaking distance.

(i) Contact opening

(ii) Contact pressure

Y Y

(d) Notch resting device.

Measurement of minimum & maximum Pressures

Y Y

9.2.4 Measurement of operating angles

They shall be made on contactors and roller contacts When passing from one notch to the next one in both Directions.

Y Y

9.2.5 Measurement of Driving Torque

To record the value of the torque on the driving shaft for the maximum & minimum value of the pressure of the notch resting device (6 Kg. M)

Y Y

9.2.6 Measurement of the value of the protecting resistor at ambient temperature

Y Y

9.2.7 Checking of the magnetic blow-out device of the contactors by breaking 5 times a resistive circuit fed with D.C. current : 110 V-40 Amps

Y Y

9.2.8 Mechanical endurance test.

The tap changer being driven by its servo-motor 20,000 complete cycles (one cycle means progression from 0 to 32 notch or regression from 32 to 0 notch) shall be made from notch 0 to notch 32 and from notch 32 to notch 0 at the rate of two notches per second. During this test, the servo-motor shall be supplied with an air pressure within 2.5 and 3.5 kg/cm²

Y N

9.2.9 Rupturing tests

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(a) Contactors 40 ruptures shall be made with 400 A-1000V -

50 c/s.

cosØ = 0.9 at the rate of 1 rupture every 20 second.

Y N

(b) Selector Contacts.

180 operation of the tap changer (switching from one notch to the following or to the following or to the preceding one) shall be made every 2 minutes during 6 hours, the tap changer feeding an inductive circuit with a current of 320 A

Voltage per notch : 1000 V – cosØ = 0.8

Y N

9.2.10 Temperature rise tests.

With a current of 400 A, 50 c/s the temperature rises shall not exceed:-

(a) Contactors (CGR) 60ºC

(b) Flexible Braids 72ºC

(c) Blow-out coils 85ºC

(d) Roller contacts 60ºC

The temperatures shall be measured with thermo-couples

Y N

9.2.11 Dielectric test

To be carried out in oil with a sine wave of 50 Hz voltage during 1 minute between (without protective resistance).

(a) Main Contactor

Pole to Pole-10 Kv, 1 Min.

Y Y

(b) Selector (in oil)

(1) Contact 0-2-4 .. to 1-3-5 .. 10 KV, 1 Min.

(2) Contact 0-4-8 .. to 2-6-10.. 15 KV, 1 Min.

(3) Contact 1-5-9 .. to 3-7-11 .. 15 KV. 1 Min

(4) Bus bar to bus bar - 10 KV, 1 Min.

Y Y

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(c) Selector (Selector & transformer side both in oil)

(1) Contact 0-2-4-6 to 32 against gearing ….. 35 KV. 1 Min.

(2) Contact 0-1 at earth against bus bars (Rolling contacts at 31 or 32) ….. 60 KV. 1 Min.

(3) Main contact, selector, contacts & gearing against pedestal (earth) …… 60 KV. 1 Min

Y Y

9.2.12 Oil leakage test

The tap changer shall be subjected to an oil pressure of 0.2 Kg/cm² & Oil leakage shall be checked after 48 hrs. at the following locations:

(a) Three way drain cock

(b) Bottom drain plug

(c) Gauge Glass

(d) Oil pump & oil flow indicator

(e) Inspection side covers

(f) Front cover joints & bolts.

Y Y

9.2.13 Weight

After Completion of the type tests, the weight of the tap changer (complete with oil & other accessories) shall be measured.

Y N

9.3 Tests of the Pneumatic Servo-motor.

Visual Inspection

Y Y

9.3.1 Measurement of the resistance of the electro-pneumatic valve coils

When cold (20ºC) the measured values shall not differ by more than ± 8% from the specified value.

Resistance values for electro valve coils shall be -

BTIL coils - 348 ± 8%

AAL(Ganz type) - 1000 ± 8%

Y Y

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9.3.2 Checking of operation

The servo-motor driving a tap changer

The coils being cold, the correct operation of the valves shall be checked 20 times, the air pressure varying between 2.5 and 3.5 kg/cm² and the voltage between 77 V d.c. and 137.5 V d.c.

Y Y

9.3.3 Valves residual stroke

The residual stroke of the armature of the magnet-valves from the position at which the valves ensure air tightness shall be measured. This stroke should not be less than 0.2 mm

Y N

9.3.4 Checking operation of tap changer at the minimum operation voltage at room temperature (within 68 V at 20ºC)

Y Y

9.3.5 Minimum operating voltage --

Type Test

A continuous heating test of the coils shall be carried out at 137.5 V DC. At the end of test the minimum voltage required for correct operation of valves shall be determined. The air pressure being 3.5 kg/cm². This voltage shall not exceed 77V DC. The final temperature rise of the coils shall be noted.

Routine Test

With the coils at room temperature, the minimum values of voltage and current required for correct operation of the valves with an air pressure 3.5kg/cm² shall be determined.

From this, compute the minimum voltage that would correspond to the temperature rise observed at the end of type test. This voltage should not exceed 77V DC.

9.3.6 Operational check.

(a) Gap of Aux contacts by a Go, No-Go gauge, (4.5 +0 / -2 )

Y Y

(b) Aux. Contact pressure (160-260 gm) Y Y

(c) Measurement of operating angle Y Y

(d) Selector with roller contacts Y Y

(e) Inner roller (positions 0,2,4) Y Y

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(f) Outer Roller (Position 1,3,5) Y Y

(g) *Lead angle –

(i) Progression - W/o push rod & with push rod (ii) Regression - W/o push rod & with push rod * not applicable for Ganz make Air motor

Y

Y

(h) Check important clearances Y Y

(i) Check correct movement of fly wheel without wobbling or slackness and without rubbing, without operating lever mechanism or cover.

Y Y

(j) Check the correct function of ratchet to prevent over shooting

Y Y

Continuous heating test.

The temperature rise of the coils shall not exceed 68ºC ( IEC No. 60077 - 20ºC ) whatever the duration of the test, when the coils are energized at a battery voltage of 137.5 V DC

Y N

9.3.7 Air tightness test --

Type Test

As soon as possible after the continuous temperature rise test, the servo-motor shall be operated 200 times at a rate of 30 operations per minute with nominal battery voltage & an air pressure of 3.5Kg/cm². Then, the air inlet shall be connected to a one litre vessel charged to a pressure of 3.5 KG/cm² the magnet-valve being energized. The air tightness shall be considered as satisfactory if the loss of pressure does not exceed 10% of the initial pressure after 10 minutes on test. The test shall be recommended with the magnet valves de-energised.

Routine Test

Same as type test but with coils at ambient temperature at the beginning of the test.

9.3.8 Test for run through time (0 to 32 notch) both for progression and regression at a pressure of 2.5, 3.0 and 3.5 kg/cm² and shall be within 9 to 13 sec.

Y Y

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9.3.9 Mechanical endurance test.

With the servo-motor coupled to a tap changer :

(a) Carry out 6,40,000 successive operations with nominal battery voltage and with an air pressure of 3.5 kg/cm².

(b) Record the operating time for a complete progression and regression under pressure of 2.5, 3 and 3.5 kg/cm² at every 50,000 operations.

Y N

9.3.10 Multiple unit operation test.

4 Servo-motor being coupled to their tap changer, carry out 200 consecutive complete progression and regressions at various conditions and with air pressure varying from 2.5 to 3.5 kg/cm².

The synchronization of the operation of the servo-motor shall be checked :

(a) With the 4 servo-motor operating.

(b) When the servo-motors are successively cut out

Y N

9.3.11 Dielectric tests

The voltage to be applied between the coils & earth so that voltage between auxiliary contacts & earth is 1500V r.m.s. 50 H.Z. for one minute

Y Y

9.3.12 Weight

The weight of the servo-motor in running condition shall be measured at the end of the type test.

Y N

9.4 Tests of the transition resistor (R1)


9.4.2 Measurement of resistance (cold) Y Y

9.4.3 Dielectric tests. Y Y

9.4.3.1 Without supporting insulators at 2.5KV, 50Hz for one minute

Y Y

9.4.3.2 With supporting insulators at 60 kV, 50 Hz for one minute

Y Y

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9.5 Tests of the air control panel (ZSM)


9.5.2 Interlocking of GR manual Handle:

Operating handle should not come out in ‘OPEN’ position, and shall be remove easily in ‘CLOSED’ position of the 3 way cock.

Y Y

9.5.3 Check air tight connection at various joints of the air pipe line, and there should not be any leakage.

Y Y

9.5.4. Check the correct program of the programme switch and its smooth operation

Y Y

9.5.5 Check correct operation of the air pressure reducer valve and pressure can be easily adjusted.

Y Y

9.5.6 Check correct operation of EP valve for tap changer oil pump air supply. Record pick up and drop out values.

Y Y

9.5.7 Run through time –

Adjust ZSM panel pressure from 2.5 to 3.5 kg/cm² by the reducer valve and check the run through time (9 to 13 sec.)

Y Y

9.5.8 Die-electric test to be carried out between aux, terminals shorted to earth at 2KvVA.C. 50 Hz. Sine wave for one minute.

Y Y

9.6 Tests on the oil pump

9.6.1 Visual Inspection. This includes air breather and oil flow indicator.

Y Y

9.6.2 Check that oil pump starts functioning at a minimum pressure of 2.5 Kg/cm². Repeat the operation for several times to ensure correct function.

Y Y

9.6.3 Check setting & proper locking of port adjusting screws

Y Y

9.6.4 Check proper operation of oil flow indicator Y Y

9.6.5 Check number of strokes of oil pump Y Y

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9.6.6 Run the tap changer oil pump for pump for two hours and at the end of test check that there is no abnormal variation in the number of strokes adjusted earlier.

Y Y

Check for oil leakage from oil pump oil flow indicator & associated pipe lines.

Y Y

9.7 Final Clearance (Routine Test)

9.7.1 Check for oil leakage zones thoroughly in the selector side and after ensuring perfect ness allow oil to be removed

9.7.2 To see oil flow indicator dismantled and packed separately and tied up properly in the same vicinity for fitment at CRJ

9.7.3 Locking of air motor parts to be ensured

9.7.4 Use of specified grease after cleaning the surfaces to be ensured on all spur gears and bevel gears. Use of lubricating oil at locations specified, to be ensured.

9.7.5 Locking of tap changer Central shaft at the other end of SMGR to be ensured

9.7.6 Marking 0 – 32 on the mounting frame to be ensured for its correctness.

9.7.7 Proper fitment of oil ducting receiving tank.

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ANNEXURE – A

INFORMATION TO BE FURNISHED BY THE TENDERER IN THE OFFER AS WELL AS IN THE INSTRUCTION MANUAL

The tenderer shall furnish the following particulars clearly in their offer. In the case of placement of an order, the contractor shall also furnish these particulars in the instruction manual with illustrations whatever possible.

TAP CHANGER

Maximum possible voltage variation per tap.

Maximum possible voltage variation per two taps.

Static turning moment on the breaker drive shaft.

Setting of the safety valve in kg/cm²

Static pressure that the contact plate will be able to withstand in kg/cm²

SHORT CIRCUIT CURRENT RATING

Welding current and temperature rise (1.0 sec.) --

Contact rollers

Circuit breaker contacts

Voltage drop at 100A, 50 Hz (circuit breaker and selector on tap 16)

Voltage drop at 400A, 50 Hz (circuit breaker and selector on tap 16).

SELECTOR

Contact pressure on the selector rollers (per contact position).

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Quantity of oil required in the selector housing at 20ºC

Grade of oil in the selector ……………………………

Type of grease to be applied on the moving parts.

Grade of lubricating oil for various specified zones

CIRCUIT BREAKER

Number of blow-out turns -

Iron Cross Section -

Contact pressure, new contacts -

Contact pressure, worn contacts -

Contact opening, new contacts -

Contact opening in maximum worn out condition -

Clearance between extinguishing chamber opening and insulating wall

-

Material of the arc chutes -

Sustained temperature rise at 400 amps. 50 c/s. of blow out coils

-

Particulars of the protective resistor (R2) -

Particulars of transition resistor (R1) -

Voltage drop at 100 A input to output -

Mean contact opening speed -

AIR MOTOR

No. of Cylinders

Resistance of the electro valve coils -

Imported torque maximum at 3 Kg per cm² (mean)

-

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Moment of inertia of the moving masses -

Air consumption per tap -

OIL FILTRATION UNIT (IF PROVIDED)

Oil discharge rate

Number of strokes per minute

Quantity of silica gel in the breather

Air consumption for the oil pump

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