In a Circuit how the MCB and Fuse ratings are calculated.
And shall the fuse follws the MCB or it is otherwise?

Answer Posted / devamanohar

The MCB rating shall be more than the fuse rating if it is
used for the service to switch off & on while the circuit
is in service.The fuse rating shall be 200% of the rated
curent normally as it is used for short circuit
protection.If the MCB is stay put type(No operation while
in service) it can be selected for rated current or 1.2
times of rated current value.

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