How does a current limiting fuse operate Explain with any ne

How does a current- limiting fuse operate? Explain with any necessary illustrations or steps.

Solution

1) fuse is perhaps the simplest and cheapest device used for interrupting an electrical circuit under short-circuit or excessive load, current magnitudes.

2) the action of a fuse is based upon the heating effect of the electric current.in normal operating conditions,when the current flowing through the circuit is with in the safe limits,the heat developed in the fuse element carrying this current is readily dissipated in to the surrounding air, and therefore,fuse element remains at a temperature below its melting point.

3)however, when some fault, such as short circuit occurs or when load connected in a circuit exceeds its capacity, the current exceeds the limiting value, the heat generated due to this excessive current cannot be dissipated fast enough and the fusible element gets heated,melts and breaks the circuit.

4) the time for blowing out of fuse depends upon the magnitude of the excessive current.