Powertech Transformers Services Powertech Transformers has over 60 years of ... of voltages up to 400kV and ratings of 795MVA. ... undertake a guaranteed complete electrical

Powertech Transformers Services

Offering our Customers Peace of Mind

Powertech Transformers has over 60 years of

experience in the transformer industry. Buying a

transformer from Powertech Transformers offers

the customer a one-stop-shop from design,

manufacturing, through to installation,

commission and ultimately maintenance of a full

range of power and distribution transformers all

the way up to the very large power transformers

of voltages up to 400kV and ratings of 795MVA.

But once you have bought your equipment, you

need to have peace of mind that it will perform at

its best throughout its entire lifespan. The sole

mandate of Powertech Transformers’

independent Services Division (PTT Services) is

to ensure that your transformer and its auxiliary

equipment operate according to their

specification and keep the sales promise that

was made. One less worry for you!

PTT Services comprises a number of highly

qualified and specialised engineers and

technicians that have a combined experience

and unsurpassed expertise of over 70 years in

installing and commissioning of transformers and

related equipment as well as service,

maintenance and performance monitoring

thereof. Their skills cover not only the Powertech

Transformers own units but a large number of

transformer brands.

Transformer Installation

Transformer Commissioning

Transformer Maintenance

Transformer Condition Assessment

A One Stop Shop for all Solution

We are able to provide an all-encompassing

service for any unit from 16 kVA up to 800MVA

at voltages up to 765kV, starting with

installation and commissioning followed by

maintenance of transformers to monitoring the

conditions that the transformer is expected to

perform under.

Our highly qualified and competent

commissioning engineers are able to

undertake a guaranteed complete electrical

testing and commissioning of transformers and

The equipment on site requires different

servicing at different stages of its life. PTT

Services focus is on

For each stage we have various service teams

who are experts in their own fields and who have

the knowledge and experience to meet our

customers’ needs. Geographic spread has not

put boundaries on our services. We will come to

you - wherever you are within South and

Southern Africa.

Proper testing and maintenance performed at

predefined intervals can uncover a problem

before a unit fails which results in costly outages.

The key to eliminating these unscheduled

outages is proactive testing and maintenance.

Information accumulated through routine

inspections and periodic testing will usually

provide warning of impending operation

problems. Recognising the warnings of an

impending failure requires careful analysis of the

records to identify significant trends or unusual

behaviour.

Local Expertise operating all over

Africa

We have local expertise based in our two

factories in Pretoria and Cape Town and a

team of technology experts available when

required to solve any problems that our

customers may encounter be it in South Africa

or any place in Sub-Sahara Africa

Our knowledge of the equipment installed is

based on the history, design review and

advanced diagnostics, anticipated fault

detection and corrective action planning

ensures greater reliability and optimisation of

network assets.

Our experts have over the decades also gain

extensive knowledge to service and maintain

transformers from other manufacturers as

In-house laboratory services at your

disposal

Within the Powertech Transformers group, we

have access to our in-house laboratory that is

fully South African National Accreditation

System (SANAS) accredited to perform the

following services to world class standards and

specifications (IEC, ISO).

Analysis of gases dissolved in oil

Testing of insulation oils

Testing of solid insulating materials

Calibration of electrical measuring

instruments


Once a transformer arrives on site, it is

imperative that the installation gets done by

experts. The future performance of the unit as

well as its lifespan can be severely affected if the

installation is not done correctly. Our installation

technicians have over seven decades of

experience in installing any size transformer,

including rigging and slinging supervision.

Although we do not provide our own transport

services, we are experienced to arrange the

transport of your unit to site through qualified and

experienced third parties.

Our strength lies in our geographic

independence. We are equipped to work on any

site anywhere in South Africa and Sub-Sahara

Africa


PTT Services is capable to provide highly

qualified, competent commissioning engineers,

and test technicians, capable of undertaking

the complete electrical testing and

commissioning of transformers and ancillary

equipment to ensure that once the unit is in

place it can smoothly operate to specifications.



the predefined intervals can uncover a problem

before a unit fails resulting in costly repairs and

outages. Regular maintenance saves you

money. Cheaper to maintain then to replace!

Careful analysis of the records and information

accumulated through routine inspections and

periodic testing can provide warning of

impending failures. It also allows us to identify

significant trends or unusual behaviour. For any

analytical laboratory services, we have access

to our own in-house SANAS accredited

laboratory.

Being part of the Powertech Transformers group

allows us access to the original design

documents to all the components installed in our

transformers and thus can order any spare parts

for replacement.

Entrust your transformers to the capable hands of

our experts. We will make sure your lights never go

out because of a transformer failure.


Enhancing the life expectancy of a transformer is

paramount to the cost effective running of any plant.

Transformers are rated amongst the more expensive

assets in their specific networks. Outages always

cost the owner huge sums of money and should be

avoided at all times.

Condition assessment provides substance for asset

management scenarios based on the company’s

strategy and the condition of the fleet. It can define

actions to be taken for each specific asset,

considering technical and economic aspects, which

can be implemented by using efficient maintenance

and repair technologies.

The transformer conditioning assessment offers a

clear understanding of the conditions of the

transformer fleet and accurate information on

possible risks associated with every unit. Two stages

for the risk analysis are proposed: Fleet Screening

and Advanced Analysis

Technical Training

PTT Service not only ensures its own people

are exposed to ongoing training, we also offer a

series of training courses to our customers to

ensure upskilling of anybody involved in the

operation of transformers.

Training course In-

house external

Infra-red thermography X

Dew point X X

Impact recorder X

TRF installation X X

Condition assessment of transformers

X X

Oil Sampling X X

FLM X X

Field testing X X

Protection components

X X

Speciliased test FDS, SFRA

X X

Head Office

1 Buitenkant Street, Pretoria West PO Box 691, Pretoria, 0001, Gauteng, South Africa Tel +27 (0)12 318 9911 Fax +27 (0)86 524 4675

Cape Town

Elliot Avenue, Epping PO Box 44, Eppindust, Cape Town, 7475, Western Cape South Africa Tel +27 (0)21 534 2681 Fax +27 (0)21 534 5383

[email protected] www.pttransformers.co.za


Once a transformer arrives on site, it is

imperative that the installation gets done by

experts. The future performance of the unit as

well as its lifespan can be severely affected if

the installation is not done correctly. Our

installation technicians have over seven

decades of experience in installing any size

transformer.

A typical installation done by us includes:

Site condition inspections, including site

access, plinth condition, clearances

Loading, transporting and off-loading of

transformers

Final positioning of transformers

After final positioning transformer assembly

with all auxiliary components, such as

conservator and pipes, radiators, bushings,

fans, cooling pumps

Vacuum and final oil filling

Head Office


Cape Town




PTT Service has highly qualified, competent

commissioning engineers and test technicians,

capable of undertaking the complete electrical

testing and commissioning of transformers and

ancillary equipment such as:

Sweep frequency Response Analysis

Winding Resistance

Tan Delta of Windings

Insulation Resistance (Megger)

Insulation Resistance of Auxiliaries

Core Ground Resistance Measurements

Transformer Turn Ratio

Vector Group Verification

Tan Delta and Capacitance Testing of Bushings

Excitation/Magnetising Current

380V Impedance test/Leakage Reactance

Current Transformer Testing

Control Equipment Overload Settings

OTI and WTI Calibration

Commissioning Test Reports

First Line Maintenance Training

Head Office


Cape Town





the predefined intervals can uncover a problem

before a unit fails resulting in costly outages.

It is therefore of utmost importance to have

planned preventive maintenance programs.

Maintenance should include comprehensive oil

testing as defined in the quality system.

Maintenance and evaluation of results should

be based upon internationally accepted

guidelines, ie ASTM; IEC; Doble; SD Meyers

and ABB.

Test results should then be used for the

following:

Frequency of planned maintenance

Evaluation of expected performance of

transformer fleet

Replacement of transformers

In this business area our service technicians are

daily on the road to perform the following

functions on transformers from 1MVA up to 800

MVA:

Inspections

After installation during warranty periods

Units stored as strategic spares

Units in operation

Oil Sampling

Paint Spot Repairs

Welding Leaks

Gasket Leaks

Bushing Replacements

Protection Component Replacements

Radiator Replacements

Oil Passivation

Infrared Thermography

Oil Vacuum Filtering

Investigate In-tank Inspections

Tap Changer Replacement and repairs

Transformer Inspections

Inspection Finding Reports

Head Office


Cape Town




Enhancing the life expectancy of a transformer

is paramount to the cost effective running of

any plant. Transformers are rated amongst the

more expensive assets in their specific

networks. Outages always cost the owner huge

sums of money and should be avoided at all

times.

The transformer conditioning assessment offers

a clear understanding of the conditions of the

transformer fleet and accurate information on

possible risks associated with every unit.

Transformer remaining life analysis

Fault and failure investigation

Dielectric frequency response

Conditioning assessment training

Oil sampling training and oil flow

measurement

Transformer fleet screening

Transformer advance analysis

Temperature measurement

Transformer assessment reports

Transformer manufacturing training

It provides substance for asset management

scenarios based on the company’s strategy and

the condition of the fleet. It can define actions to

be taken for each specific asset, considering

technical and economic aspects.

It can implement defined actions by using

efficient maintenance and repair technologies.

Two stages for the risk analysis are proposed:

Fleet Screening and Advanced Analysis

(typically 10 - 20 % of fleet)

Transformer Status: A Transformer energised B Transformer de-energised C Transformer disconnected

Fleet screening

Analysis of dissolved gases in transformer oil is

being recognised worldwide as being an

essential diagnostic tool for the early detection of

incipient faults in transformers. It is an extremely

cost effective method to monitor the condition of

power transformers.

The fleet screening steps give an initial good

idea regarding the general condition of each

transformer and possible needed maintenance

actions such as drying, oil reclaiming, oil

degassing and additional cooling. It also allows

selecting a subset of the fleet that needs more

advanced analysis.

Details of the Fleet Screening services rendered

include:

1. Detailed visual inspections

Status of gaskets, accessories and protection devices

Reporting on findings and repair of defects

2. Oil sampling, analysis and reporting

Chemical and physical status of the oil

Dissolved Gas Analysis

Furanic Analysis

Predicted Degree of Polymerisation of the solid insulation

3. Thermal status of the transformer

Cooling system inspection and verification by means of direct temperature recording of all fibre optic point measurements for a period to be mutually agreed upon (where applicable).

Oil flow rate measurements can be taken and compared against design values (Oil Forced Air Forced (OFAF) Cooling only)

4. Thermal imaging of transformer

Bushing connections

Marshalling kiosk

Tap changer motor drive cubicle

Busbar connections

Advance analysis

The advanced analysis entails an evaluation of

the main properties of the transformers using

advanced diagnostic tests. The process also

starts with the four steps of the fleet screening

and then continues with:

5. Accessories verification and testing

Buchholz

Temperature indicators (OTI & WTI)

Oil Level indicators

PRV’s (Pressure Relief Valves)

6. Electrical tests

Insulation resistance

Turn to Turn Ratio (TTR)

Winding DC resistance

Capacitance and power factor/dielectric losses for bushings

Dielectric dissipation factory (tan-delta) and capacitance measurement for windings

7. DFR (Dielectric Frequency Response)

Analysis

Status of the insulation system (oil-paper)

8. SFRA (Sweep Frequency Response Analysis)

Mechanical status of the active part

Head Office


Cape Town



Documents

Powertech Transformers Services Powertech Transformers has over 60 years of ... of voltages up to 400kV and ratings of 795MVA. ... undertake a guaranteed complete electrical