How would you distinguish between a MCB and an MPCB ?

How would you distinguish between a MCB and an MPCB ?

Let me first confirm that you are referring to circuit breakers

It so

MCB = Miniature Circuit Breakers
MPCB = Motor Protection Circuit Breakers

MCB are designed for a wide variety of functions circuit protection functions while MPCB’s are used for the specific function of protecting circuits driving electric motors. MPCB’s usually have thermal and magnetic trips or mechanism to break the circuit when necessary. MPCB are usually more expensive for the same control ratings because they are more complicated.