Fuses and circuit breakers

A fuseFuses are safety devices, which protect electrical appliances by preventing too much electric current flowing through them. The fuse is a thin wire inside a protective case. If too much electric current flows through the wire, it melts and stops the current flowing. is a safety device which stops electric currentElectric current is a flow of electric charges (electrons). flowing if an electrical appliance goes wrong and causes the electric current in the circuit to get too big.


Three types of fuses are found in mains plugs: 3A, 5A and 13A. Each fuse contains a special piece of wire which melts once the current reaches the limit. When the wire melts it makes a gap in the circuitA collection of wires and electric components connected together in such a way that electric current can flow through them. and so the current stops flowing.

The mains electricityElectric current supplied to our homes from the national grid. circuits in our homes are also protected by fuses. These are usually in a fuse box near the electric meter. If there's a problem with an electric appliance the fuse in the plug might 'blow' and sometimes, the fuse in the fuse box blows too.

Some homes have circuit breakers instead of fuses. They do the same job as fuses but they don't rely on melting wires. There are usually quite a few circuit breakers - one for each of the mains electricity circuits in the home.

Consumer unit


Find out more about the mains circuits in your home.


Did you know?

Show all