Purpose of start up protection? Is it always in service?

Purpose of start up protection? Is it always in service? 
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1 Answer

Answer :

Trips the generator. If generator is excited with internal fault the over current 50s trip the generator to prevent major damage. The earth fault relay 64c also. The relays are polarised dc armature type, sensitive to all frequencies, since the frequency need not to be 50 Hz initially during start up. Start up protection is cutout as soon as generator CB is closed.  
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