Earth Fault

any one tell me,the difference between earth fault,restricted earth fault ,stand by earth fault,sensitive earth fault and special purpose of each

Positive ,negative And Zero Sequence

Hi everyone
Any one can tell me,what is the physically concept of positive ,negative and zero sequence.

I know these all are the componets of the unbalanced system but i want to know about the physically significance and concept.

Regards,

Shahid Hafeez

End Fault

Could any tell me,What are the End Fault and How we can Over come these tyoe Fault

Isolator

Hi Everyone

I have to ask

1-Why the isolator install before the circuit breaker,i know it provide the visible isolation but i want to find

out the technically reason

2-A signal provided in AVR(Auto voltage regulator) "Out of Step"what is the purpose of this signal.This AVR

usally installed in Power transformer and Auto transformer for voltage regulation.

Overload And Overcurrent Relay

Hi Guys,

Could any one tell me, the difference b/w Over current and overload relay.

What the difference b/w Permissive under reach and Over reach Protection .

what is the stub protection.

what is the SOTF protection.


Regards,

Shahid Hafeez