mccb & mcb

mcb means miniature circuit breaker. mccb means moulded case circuit breaker. mccb have higher ratings as compared to mcb.

contued from above ans...

in mcb, the trip characteristics cannot be adjusted whereas in mccb, the trip characteristics can be adjusted in some. the operation principle can be either thermal or thermo-magnetic.

how can adjust the tripping characteristic

the tripping characteristics can be adjust only in some special type of MCCBs called as ICCB. in them the characteristics can be adjusted but to a limited extent.

Electrically - the rating and the breaking capacity. MCB ratings can be up to a maximum of about 125 Amperes and breaking capacities upto 10kA. MCCB ratings can be upto 3200A and breaking capacities upto 75kA.

Mechanically - not much difference except frame size. MCB can be called a 'miniature moulded case circuit breaker'.

I'll only add that Mechanically, there is a huge difference in construction, hence the higher interrupt capacity of the MCCB. At anything approaching a high current fault, an MCB becomes shrapnel. It just cannot withstand the physical forces involved. And MCCB is designed for that.