Changing a fuse in a consumer unit

For a consumer unit with cartridge fuse carriers:

Tools and Materials:
A torch, fuse tester, screwdriver, correct amperage fuse cartridge.

• Switch off the main power switch on the consumer unit. Sometimes with older consumer units, when a fuse blows the power switch will automatically be thrown into the off position, but double check just in case.
• Locate which fuse has blown by removing each fuse carrier and test the individual fuse cartridge within using a fuse tester.
• Removed the blown fuse cartridges from the carrier. Some fuse cartridges are held in spring clips while others are held by screws.
• Either pull the cartridge fuse out of the clips or loosen the screws to release the cartridge fuse.
• Replace the faulty cartridge fuse with the equivalent new cartridge.

N.B. The replacement fuse cartridge must be of the same amperage. NEVER replace a fuse cartridge with one of a higher amperage as this could cause a fire. See below for the amperage and colour of cartridge fuses and their typical use. If you are uncertain, call in a qualified electrician to help.

• Re-assemble the cartridge fuse holder and slot in back into the consumer unit.
• Switch on the main power switch.

For a consumer unit with wire fuse carriers:

Tools and Materials:
A torch, screwdriver, wire cutters, correct amperage fuse wire.

• Switch off the main power switch on the consumer unit. Sometimes with older consumer units, when a fuse blows the power switch will automatically be thrown into the off position, but double check just in case.
• Locate which fuse has blown by removing each fuse carrier and inspecting the thin fuse wire contained within. The blown fuse will be the one with the broken wire.
• Select the correct fuse wire to replace the broken fuse wire.

N.B. The replacement fuse wire must be of the same amperage. NEVER replace a fuse wire with one of a higher amperage as this could cause a fire. See below for the amperage of fuse wires and their typical use. If you are uncertain, call in a qualified electrician to help.

• The fuse wire will be held in place by two screws terminals located at the top and bottom of the fuse carrier.
• Unscrew these terminals to allow the wire contained to be removed. Keep the screws loosely held in the terminals.
• Using the correct amperage fuse wire, take a strand longer than the carrier unit and pass it through from one terminal to another.
• Leaving some slack on the wire secure the two ends of the wire around the terminal screws.
• Tighten the terminal screws back into their positions on the fuse carrier to secure the new length of fuse wire within.
• Replace the fuse carrier back into the consumer unit.
• Switch on the main power switch.

Fuse Amperages and their typical uses:

Reproduced with permission from www.ProblemSolved.co.uk. The website contains 70,000 reliable and recommended tradespeople from plumbers to interior designers and everything in between!

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