Replacing a Fuse and Resetting a Circuit Breaker

Replacing a fuse and resetting a circuit breaker is an easy DIY job. Below we share the basics on what you need to know and what you need to do, to get everything up and running again. Always follow appropriate safety guidelines when tackling electrical DIY.

Fuses and Fusebox

Fuse – This is a protective device that cuts off the current if the circuit is overloaded or a fault develops in the electrical system.

Fusebox – This is normally connected by two single cables from the meter. The main fusebox is often called the consumer unit. The job of this unit is to divide up and distribute the electrical current to the various circuits in the home and allow you to turn off the whole installation or any part of it – for repair or for extending the system. Each circuit in a home is also protected by passing it through a circuit fuse. If there is a fault or if the circuit is overloaded the fuse will blow. This warns you that there is a fault and also cuts off the power to the circuit, ensuring it is safe, and allowing you or a suitably qualified person to carry out any necessary repairs.

Circuit Breaker

A circuit breaker is an automatically operated electrical switch which protects an electrical circuit from damage caused by overload, malfunction or short circuit. a circuit breaker doesn’t need replacing on a regular basis, unlike a fuse, which operates once and then has to be replaced when blown, a circuit breaker can be reset – either manually or automatically so it can resume normal function. Circuit breakers are made in varying sizes – devices that protect an individual household appliance, breakers that protect circuits within the home or breakers which protect much bigger electrical systems – in industry, for example.

Fused Connection

These are special types of outlet to which the flex of the appliance is permanently connected. Fused connection units are useful for fridges so you can avoid accidentally unplugging. The unit is usually fitted to the wall. Most designs allow easy access to the fuse through a flap on the front of the unit. The connections are the same as for conventional sockets, except that you also have to connect the flex. There are six separate terminals which take the individual cores of the cable and the flex.

Mending a Fuse

If a fuse blows then you have a fault somewhere in the system. You must ensure the fault is put right before replacing or mending the fuse and switching on again. There are two types of fuse:

Modern Cartridge Fuses – Used in plugs and modern fuse boxes. All you have to do is remove the fuse and replace it with a new one between the two metal holders in the fuse carrier. Always check you have the correct rating for your appliance or system.

Older Wire Fuses – These use wire instead of a cartridge. To repair these you need to remove the wire and replace it with a new wire with the correct rating. Use enough wire to pass right through the fuse and wrap around both the terminals. There should be a screw terminal at either end.

Replacing a Circuit Breaker

• Turn off the light switches and unplug appliances.
• Locate your circuit breaker.
• Locate the tripped breaker. Circuit breakers are normally small switches and should be labeled to identify the area they serve, e.g. kitchen, ground floor. A tripped circuit breaker should be in the off position or in a middle position between on and off.
• Reset the breaker by moving it to the full off position and return it back to the on position.
• In most cases that will clear the power overload and return power to the affected area.
• If the breaker continues to trip the cause could be that you have too many appliances switched on in that circuit. Alternatively you could have a damaged appliance, switch, fitting – or damaged or faulty wiring.
• If there is a fault you need to identity and mend the fault before resetting the circuit breaker. You may need to contact a qualified electrician.

Ask the Experts

Whether you have a fuse or a circuit breaker that needs fixing the procedure is the same. Turn everything off and locate and repair the problem. Always be aware though that working with electrical systems and appliances carries potential risks. If you have any doubts contact an appropriately qualified electrician and seek professional advice.