Consumer Unit Fuses

Consumer unit fuses are cartridge fuses that protect individual circuits in older fuse boards, before circuit breakers became standard. We currently stock Lawson cartridge fuses in 5 Amp (LA5), 15 Amp (LC15) and 30 Amp (LD30) ratings, used for lighting, immersion and ring or cooker circuits respectively on many existing boards.

Account customers buy at trade prices, and in-stock fuses ordered before the 5pm weekday cut-off are delivered the next working day across NI and ROI.

LA5 In-Stock

Lawson 5 Amp Consumer Unit (LA5) Fuse

£0.78 inc. VAT

LC15 In-Stock

Lawson 15 Amp Consumer Unit (LC15) Fuse

£1.38 inc. VAT

LD30 In-Stock

Lawson 30 Amp Consumer Unit (LD30) Fuse

£1.52 inc. VAT

Replacing consumer unit fuses

Cartridge fuse boards remain in service in many older properties. When a fuse blows, the replacement must match the original exactly, and the board's overall condition is worth assessing at the same time.

Matching the right fuse

Rating - typically 5A for lighting, 15A or 20A for immersion heaters and smaller radials, and 30A for ring circuits and cookers, but always go by the existing circuit design.
Type code - Lawson codes such as LA5, LC15 and LD30 identify the size and rating.
Physical size - cartridge fuses of different ratings are usually made in different sizes so a higher rated fuse cannot easily be fitted into a lower rated carrier.

Changing a fuse safely

Switch off the main switch before removing a fuse carrier, replace the cartridge with an identical rating, then refit the carrier and restore power. If the new fuse blows again, the circuit has a fault and should be investigated by a qualified electrician. Never fit wire or a higher rated fuse.

When to consider upgrading

Older cartridge boards usually lack RCD protection, which is now expected for many circuits under current wiring regulations. During rewires, alterations or periodic inspections, electricians often recommend replacing the board with a modern consumer unit fitted with MCBs and RCDs, or individual RCBOs. This should only be carried out by a competent person.

Other fuses

Our wider fuses range covers plug top, cut-out and Neozed fuses.

Meteor Electrical is a family-run wholesaler based in Cookstown, Co. Tyrone, with depots in Cashel and Saggart. Delivery is free over £30 / €35 ex VAT, and our team is on 028 8675 1515 (048 8675 1515 from ROI) from 8am to 5pm on weekdays.

FAQ's Ask Your Own Question

What are consumer unit fuses used for?: Consumption Unit Fuses are intended for usage in single-phase consumer units and other single-phase installations that have fault levels.
What is a fuse?: A fuse is a piece of wire designed to transport a specific amount of electricity, which is defined by the thickness of the wire in the fuse.
What fuses are available?: At Meteor Electrical we have a wide range of amps available for consumer unit boards from 5-30 Amps.
How do you check a consumer unit fuse?: A proper tester, such as a multimeter or a continuity tester, will be required to test a fuse. You can test a fuse using an earth test screwdriver by tapping one end of the fuse with the screwdriver and holding the other end of the fuse; if the fuse flashes, it has not blown! Replace the fuse in the consumer unit, replace the cover, and re-energize the main switch.
Why are consumer unit cartridge fuses different sizes?: Cartridge fuses for older consumer units are made in different physical sizes for different ratings so that a higher rated fuse cannot easily be fitted into a carrier meant for a lower rated circuit. This helps stop cables being under-protected. Always match the fuse code, such as LA5 or LD30, to the original.
Should I replace an old cartridge fuse board with a modern consumer unit?: In many cases yes, because older fuse boards usually lack the RCD protection expected by current wiring regulations and may use combustible enclosures. A modern consumer unit with MCBs and RCDs or RCBOs improves protection against shock and fire. A qualified electrician should inspect the installation and carry out any replacement.
Can I fit a circuit breaker in place of a cartridge fuse?: Only if the board manufacturer offers a compatible plug-in breaker designed for that specific fuse carrier position. Improvised conversions are unsafe. For most older boards, the better option is to replace the whole board with a modern consumer unit, which should be done by a competent electrician to current wiring regulations.