Question { Power Grid, 21051 }

HOW many type of Circut Breaker in the world used in 400 kv
substation?

Answer

well i wnt be able to assure with this one but i guess there
are three: Air ckt breaker, MCCB's and vaccum CB'srarely used)

Question { ABB, 72032 }

What is the difference between Isolator annd Circuit
Breaker.

Answer

Circuit breaker is the device such as ACB's or MCCB's which
trips the entire system if there is a failure. By the entire
system we mean the elements connected to the particular
busbar of that crcuit breaker.
An isolator is used to cut out a portion of a substation
when a fault has occured on a particular portion of the
whole station to rectify it and repair it and in the
meanwhile the other devices operatee without being affected
by the faulty part.

Question { Power Grid, 12265 }

1.generator rated as 1000 mva,11kv .8 pf what will 0.8 pf
will indicate?
1.max pf it can supply 2.min pf it can supply
like this 4 options there what is answer.explain

Answer

max p.f. it can supply

Question { Power Grid, 15949 }

What is the direction of rotation of blades in a table fan
and in a ceiling fan ?

Answer

anticlockwise