A circuit breaker fulfils the same function as a fuse. If a current gets too high, it breaks the circuit. Current can not then flow and the reason for the high current can be investigated and corrected.
A circuit breaker through, has several advantages over a fuse
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It can act more quickly
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It is more reliable
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It can be reset – each time a fuse acts to break a circuit, it must be replaced
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The RCCB (residual current circuit breaker) is very sensitive
There are two main types of circuit breaker.
The MCB (miniature circuit breaker) acts to break the circuit at a set current – typically 1A, 13A or 30A.
The MCB might not prevent you being electrocuted. To prevent electrocution, use an RCCB. This cnsists of coils of wire wound in opposite directions on a soft iron core. If the currents are equal the magnetic fields cancel each other out. If there is a current leakage, there will be a net field in the coil. The residual magnetic field trips a relay and breaks the circuit very quickly.
