IS THE BREAKING CAPACITY IMPORTANT?

Yes, very important! A fuse must be able to open the circuit during a short circuit without losing physical integrity. In other words, it should be able to exist under a maximum fault level load without physically cracking or disintegrating. The breaking capacity of a fuse is the maximum available current, at the rated voltage that the device can safely open without physically rupturing. The breaking capacity of the fuse must be greater than the potential fault (short circuit) current of the circuit.

The Breaking Capacity is also known as the ‘Interrupting Rating’. It is expressed in amps (A) but breaking capacity values are often large numbers.

For example, a breaking capacity of 120,000A is usually expressed as 120kA.