Miniature circuit breaker(MCB)

Miniature circuit breaker(MCB) can be defined as a automatically operated electrical switch designed for the purpose of protection of any electrical circuit from damage that can occur by overload or short circuit. Basic function of MCB is to detect a fault condition and to stop flow of electrical current. Contrary to a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.

Types of MCB

Depending upon our requirement and phase of current to be used we use various MCBs like 1 Pole,2 Pole, 3 Pole, 4 Pole

1 Pole MCB

 

2 Pole MCB

 

3 Pole MCB

 

4 Pole MCB



MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.

There are three main types of MCBs:

1. Type B - trips between 3 and 5 times full load current

2. Type C - trips between 5 and 10 times full load current

3. Type D - trips between 10 and 20 times full load current


The miniature circuit breaker (MCB) plays an important role in providing overcurrent protection and a disconnect means in electrical networks.


The Magnetic trip unit protects against a short circuit. The magnetic trip unit is comprised of an electromagnet and an armature.