Plain English
What is actually in your fuse board?
Knowing what the box on your wall does makes it much easier to describe a problem — and to judge whether a quote is fair.
- Main switch — turns off the whole installation. Worth knowing where it is before you need it.
- RCD — cuts the supply within milliseconds if current leaks to earth, which is what protects you from a serious shock.
- MCBs — the individual circuit breakers. Each one protects a circuit such as upstairs sockets or downstairs lights.
- RCBOs — a combined RCD and MCB on a single circuit. If one circuit faults, only that circuit goes off instead of half the house.
- SPD — surge protection, now commonly fitted to guard sensitive electronics against voltage spikes.
See what a consumer unit upgrade involves →