MCBs or Miniature Circuit Breakers are electromechanical devices which protect an electrical circuit from an overcurrent. The overcurrent, in an electrical circuit, may result from short circuit, overload or faulty design. An MCB is a better alternative to a Fuse since it does not require replacement once an overload is detected. Unlike fuse, and MCB can be easily reset and thus offers improved operational safety and greater convenience without incurring large operating cost.
The principle of operation is simple. An MCB functions by interrupting the continuity of electrical flow through the circuit once a fault is detected. In simple terms MCB is a switch which automatically turns off when the current flowing through it passes the maximum allowable limit. Generally MCB are designed to protect against overcurrent and over temperature faults (overheating).
Protecting electric circuits from overload conditions
Protecting against short circuits and other electric faults
Circuit switching, although this is not very frequent and isn?t the main function of the MCB
A breaker is a device designed to isolate a circuit during an overcurrent event without the use of a fusible element.
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