What is difference B/N MCB & MCCB..???

Miniature Circuit Breaker (MCB) :

The miniature circuit breaker is an electro mechanical device which, automatically, switch off the circuit whenever the abnormal condition occurs. It easily senses the over current caused by the short circuit.

The working principle of the miniature circuit is very simple. Their main function is to protect the equipment from over current. It has two contacts one is movable, and the other one is fixed. When the current increases from the predefined limit, their movable contacts are disconnected from the fixed contacts which make the circuit open and disconnects them from the main supply.

Moulded Case Circuit Breaker (MCCB) :

The MCCB stands for moulded case circuit breaker. It is a protecting device which protects the circuit from overloading. It is mainly used in a place where adjustable tripping requires. The current rating of MCCB is up to 2500 amps. It is mainly used for high current applications. The MCCB has a manually operated switch for tripping the circuit.

The MCCB has two arrangements. One for the over temperature and the other for the over current. It consists bimetallic contact which expands and contracts when the temperature of the MCCB changes.

During the normal operating conditions, the contact allows the current to flow through the circuit. But as the current rises beyond the predefined value, then their contacts will warm and expand until the contacts are open. Thus, disconnected the circuit from the main supply and protects the equipment from damage.

Comparison of MCB & MCCB :

One of the major difference between the MCB (Miniature circuit breaker) and MCCB (Moulded case circuit breaker) is that the interrupt rating of the MCB is up to 1800 amps whereas the interrupt rating of the MCCB is between 10k – 200k amps. The other differences between them are explained below in details.

Basis for Comparison	MCB	MCCB
Definition	Type of switch which protects the system from overloaded current.	Protects the equipment from over temperature and fault current.
Abbreviation	Miniature Circuit Breaker	Moulded case circuit breaker.
Tripping circuit	Fixed	Movable
Pole	Available in single, two and three versions.	Available in single, two, three and four versions.
Interrupting Rating	1800 A	10k -200k
Remote on / off	Not Possible	Possible
Rating Current	100 amps	10 - 200 amps
Applications	In lightning circuit and for low loads.	In heavy current circuit
Uses	For domestic purpose.	For commercial and industrial use.