Before i explain the Importance of Miniature circuit breaker or MCB, you have to understand what a circuit breaker is and its relation to a fuse. I have simplified these articles for everyone, anyone can understand it. Enjoy
A circuit breaker is protective device which is designed to automatically break an electrical circuit from from flowing to prevent Dangerous electric faults. In a layman's term, it means the circuit breaker will switch off all electronic device when it senses Danger. This fault can be due to over load, short circuits and sometimes earth faults. With the presence of a circuit breaker in the Inverter, it will prevent harm and damages to equipment and personnel.
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Difference between Circuit Breaker and Fuse
A circuit breaker and Fuse perform the same function but they work in different ways. A fuse is a part of the circuit which consists of conductor which melts easily and breaks the connection when current exceeds the predetermined value. An electrical fuse is a weakest part of an electrical circuit which breaks when more than predetermined current flows through it.






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What is MCB?
Nowadays we use more commonly miniature circuit breaker or MCB in low voltage electrical network instead of fuse.

The MCB has some advantages compared to fuse.

1. It automatically switches off the electrical circuit during abnormal condition of the network means in over load condition as well as faulty condition. The fuse does not sense but miniature circuit breaker does it in more reliable way. MCB is much more sensitive to over current than fuse.

2. Another advantage is, as the switch operating knob comes at its off position during tripping, the faulty zone of the electrical circuit can easily be identified. But in case of fuse, fuse wire should be checked by opening fuse grip or cutout from fuse base, for confirming the blow of fuse wire.

3. Quick restoration of supply cannot be possible in case of fuse as because fuses have to be re-wirable or replaced for restoring the supply. But in the case of MCB, quick restoration is possible by just switching on operation.

4. Handling MCB is more electrically safe than fuse.
Because of to many advantages of MCB over fuse units, in modern low voltage electrical network, miniature circuit breaker is mostly used instead of backdated fuse unit.

Only one disadvantage of MCB over fuse is that this system is more costly than fuse unit system.

http://www.charpell.com/2015/03/importance-of-mcb-in-inverters.html

thanks for this...