State use of any four relays for the protection of traction transformer.

State use of any four relays for the protection of traction transformer. 
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1 Answer

Answer :

Relays for the protection of traction transformers: 

 Inverse time over current relay as back up protection on primary (HV side) – over current protection of transformer and other equipment. 

 over current relay on LV side – over current protection of transformer 

 Overload thermal relay – protection against sustained overloads on transformer 

 Earth fault relay – earth fault protection of transformer. 

 Buchholz relay – protection from incipient earth or inter winding faults inside the transformer
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