Miniature Circuit Breakers

01. what is MCB and how does it work? 

MCB is designed to protect an electrical circuit from damage caused by excess current, typically resulting from an overload or short-circuit. Its basic function is to interrupt current flow after a fault is detected.

02. Working principle of circuit breaker

The most important thing that circuit breaker is doing is to safely and reliably switches off electrical circuit during abnormal conditions of the network. 

First incoming terminal, then contact point of moving in fixed contacts, then magnetic coil, then bimetallic strip, then outgoing terminal. All are arranged in series. 

Under overload condition the current through the bimetallic strip causes to raise of the temperature of it. The heat generated within the bimetallic is enough to cause deflection due to thermal expansion of metals.

In tripping operations, an arc is formed when the contact starts separating. This arc is then forced into arc chute plates, where arc is formed into a series of arcs and at the same time energy extracts and cools it. 

Types of miniature circuit breakers miniature circuit breakers are classified into three major types according to their instantaneous tripping currents, Type B, type C, type D.