Final Circuit Protection

[Locus]

Hi Everybody

Why fuse is no longer use in Final Circuit Protection. Instead, Circuit breakers are used.

So far, I know that CB is more sensitive than fuse.

Can someone depicts any reason and their respective curves.

Thanks

 

[Ian1981]

Have a look in appendix 3 of bs7671 for the time/ current curves of both fuses and mcbs.
Also fuses to bs 88 are still used for circuit protection for things like distribution circuits.
Perhaps you mean bs 3036 rewireable fuses no longer used?

 

[Richard Burns]

Fuses can still be used if required, however a fuse requires replacement when it operates whereas a circuit breaker can (usually) be reset.
Therefore the maintenance costs are lower and re-energising a circuit is easier with circuit breakers so they are the preferred method.
Fuses may be used more often upstream in the circuit as they can provide discrimination and, if the cascading works, will not operate often.