Category: Testing and Commissioning

Pre-Commissioning check for indoor vacuum circuit breaker

basicelectricaldesign
Breaker Contact Resistance Test

Testing and commissioning of indoor Vacuum circuit breaker Physical Inspection and Mechanical checks:- Check the circuit breaker, vacuum bottle and insulators for cracks or other signs of physical damage. Check the tightness of connections, including flexible connection between vacuum bottle and busbar. Switch off control power to the breaker of disconnect the control plug. Discharge the closing and tripping springs- this done by first tripping the breaker (if it is closed), then closing the breaker, then tripping it again. Open the cover of the mechanism box. Check for damage, check…

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Voltage Transformers testing and commissioning Guidelines

basicelectricaldesign
Voltage Transformers ratio check

Potential / Voltage transformers Testing and Pre-Commissioning Check   Potential /Voltage transformers can be broadly divided in to two type : Indoor and outdoor type. Indoor type – Cast resin. Outdoor type – Live tank, Oil cooled.These can be of electromagnetic of capacitive voltage transformer type (CVT). PT rating  are specified as follows –  1) Metering Core-  132 KV /3 : 100v / 3 – nominal ratio 100 VA – Rated burden Class 1.0- Accuracy is 1 %, between 80 % and 120 % of rated voltage and with burdens between 25…

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Current transformers Testing and Commissioning Guidelines

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Commissioning Procedure for Current Transformers Current transformers (CTs) can be broadly divided in to two type, Indoor and outdoor type. Indoor type – Cast resin : wound type and window type. Outdoor type – Live tank , Oil cooled and dead tank , oil cooled. CT rating are specified as follows- Metering core 200/5 – nominal ratio 15VA – Rated burden : the maximum burden (i.e. impedance) that may be connected on the CT secondary side. Class 1.0- Accuracy at 100% rated current and burden is 1.0% Protection Core 200/5-…

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Power Transformer Testing and Commissioning Guidelines(Oil Type)

basicelectricaldesign
Testing of stability of transformer differential Scheme

Commissioning Procedure Of Power Transformer  In Transformer testing it can be classified into power and distribution transformers. It Rating plate show nominal voltage, current of  primary and secondary voltage at various of the tap changer, connection symbols ( vector group), % impedance weight of oil etc. Before starting transformer testing some of per-commissioning checks a physical inspection of transformer is to be carried out along with the general arrangement drawing.The parts mentioned on the drawing are to be checked for physical mounting. Check the following points before start the  Transformer…

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