Fuse

A fuse is a safety device that is connected in series with the live wire in the circuit to protect the equipment when excess current flows.It is short and thin piece of metal wire that melts when large current passes through it.If a large,unsafe current passes through the circuit,the fuse melts and break the circuit before the wires become very hot and cause fire.

Fuse are normally rated as 5 A,10 A,13 A,30 A,etc.

Following safety measures should be taken while using fuses in household electrical circuits.

(1) Fuses to be used should have slightly more rating than the current which the electrical appliance will draw under normal condition.For example,for lightning circuit choose a 5 A fuse as the current draw my each lamp is very small about 0.4 A for a 100 W lamp.In such circuit,10 lamps of 100 W can be safely used as the total current drawn is only 4 A which can be calculated using formula P=VI

(2) Fuses should be connected in live wire so that the appliance will not operate after the fuse has blown.

(3) Switch OFF the main before changing any fuse. 


Different Types Of Fuse:-