what is the diff. b/w restricted earth fault relay &
standby earthfault relay and where they are used?

Answer Posted / ramniveth

i agrre with this answer with little correction
Standby Earth Fault relay is also connected to star side

the difference between SEF and REF is REF operates in
InZone only
SEF operates in In and Out Zones. If there is an earth
fault in outgoing feeders and the feeder protection is not
operated then SEF operates .
Tripping time for SEF will be more than REF and Earth fault
protection in O/G feeders.

Is This Answer Correct ?    112 Yes 11 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

in general it is observed in power stations, the tertiary winding is used in higher rating Y-Y auto transformer but not in Y-Y power transformer. is the tertiary winding is compulsory then why it is not using in power transformer 

1300


Can we use a absolute encoder to show rpm of a motor ? what about the condition when power is off ? what is difference if a incremental one is used ?abanirout@gmail.com

1584


explain transformer ct connection?

1615


what's the requirement of Dy11d0 connection of 3 phase transformer?what's use of it?

7388


What is class ab operation?

643






what is mean by ideal infinite bus? why it is required to consider in fault short circuit calculations?

2240


can we install HT panel & LT panel side by side or how much clearance is required ?

1097


"TRANSFORMER MODELING AND ANALYSIS" MEANS WHAT AND WHICH TOPICS U READ IN THIS

1423


What is inrush current?

645


Can you explain about TEE protection scheme?

1761


May I know how much values to be set for earth fault, over current and short circuit values at 11kv side? I have 11kv van 1250amps rating. Present it's taking load 80amps?

1028


what maximum range of star & delta in hp or kw ?

1280


What should be current in the Primary and secondary side of 1000KVA (11KV Supply)Transformer.?

637


Explain the iniluencc of short circuit ratio on the pert'orniancc of synchronous machine.

1712


What is meant by harmonic distortion?

675