MCB means miniature circuit breaker--It is thermal &
magnetic trip device operating upto 100 A. It's range is
fixed not selectable.
MCCB means Moulded Case Circuit Breaker---It is operated
upto 1000 A and High voltage MCCB also operates on 1200 A
also...And it's range is selectable..
ELCB means Earth Leakage Circuit breaker---It is operated
on leakage current only..It is not operated on short
circuit or overload current.
RCCB means Residual Current Circuti Breaker---it's Working
principle is same as ELCb..It is also operated on Leakage
current..Main differance between it and ELCB is that it is
also operated on Short circuit current
mccb-minurate current circuit breaker it used upto 1000A,
it should withstand that capacity
mcb-miniurate ciruit breaker it used upto 63A only for
elcb-earth leakage circuit breaker it used for any leakage
current in cable, then it should trip under earth fault
last week we did the REF relay test by closing single pole
(R phase) of CB and apply 380V at the primary of delta
transformer. we get 33A at the primary of the R phase star
end. but we get 380A at both R an B in delta side. how and why?