How to Replace a Circuit Breaker Fuse

When you need to replace a circuit breaker fuse, remember that electricity can be dangerous. Always exercise caution and show respect for electricity to avoid harm.

Circuit breakers are part of the main electricity distribution system within your home. They are found in the circuit breaker box—often referred to as the "fuse box." Circuit breaker fuses provide a safety mechanism that disconnects electricity supply to a circuit in your home if something goes wrong.

Circuit breaker fuses may need replacing if they repeatedly switch off for no apparent reason, if they refuse to reset or if they do not switch off when they should.

Follow these steps to replace a circuit breaker fuse:

Step 1: Ensure Personal Safety

Wear rubber soled shoes and ensure the floor beneath the circuit breaker box is dry.

Step 2: Remove Cover

Remove the circuit breaker box cover by unscrewing the corner screws with a screwdriver.

Step 3: Switch Off Mains

Push the main electricity switch, to the individual fuses, into the “Off” position.

Step 4: Identify Fuse to be Replaced

The push-lever of a fuse that frequently trips will be found in the “off” position, in contrast to the other switches. A circuit breaker fuse that will not reset will be in the “off” position and cannot be returned. A fuse that refuses to trip when it should will probably show marks of overheating or damage.

Step 5: Check for Current

Turn the damaged fuse to “off” position. Set your multimeter to “Volt AC” and rest one pin on the terminal screw of the faulty fuse and the other on the “ground” screw, which lies opposite in a row or bar at the side of the box. The reading should indicate no voltage.

Step 6: Remove the Fuse

To remove the circuit breaker fuse you will either need to unscrew it or you will simply be able to pull or lever it from its socket.

Step 7: Detach Connecting Wires

The fuse will remain connected to either one, or two, wires. Detach these by loosening the terminal screws. Make a mental note of which color wire attaches to which end of the fuse.

Step 8: Check Fuse Amperage

It is important that the replacement circuit breaker fuse is of the same amperage (and voltage unit) of the original. You may wish to take the old fuse to the store in order to purchase the correct replacement.

Step 9: Rewire New Fuse

Set the new fuse to the "off" position. Insert the original wires, in turn, into the terminals of the new fuse and tighten the retaining screws with a screwdriver.

Step 10: Insert new Fuse

Push the new fuse back into its socket and, if supplied with retaining screws, tighten screws after inserting them with a screwdriver. Push the lever switch into the “On” position.

Step 11: Reconnect Supply

Flip the main switch to the circuit breaker fuse box back on. Replace the box cover, insert the screws screws and tighten them with a screwdriver.