Understanding the Fuse board

Your fuse board is at the heart of the electrics in your home. While you’d always call an electrician if something goes wrong, it can be helpful to have some basic understanding of how it works to help you in running your home. 

What is a fuse board?


Your fuse board, also called a consumer unit, is responsible for distributing electricity around your home. It’s also where you would go if you want to turn off the electricity, for example, because you need to change a lightbulb. 

How does a fuse board work?

Your fuse board has three main components:


  • The mains switch
  • The circuit breakers
  • The Residual Current Devices (RCDs)

The mains switch

The mains switch is what you might expect it to be: it turns all the electrics in your home off and back on again. So if you need to shut off the electrics in an emergency, this is what you would use. It’s also useful if you need to switch off the electricity to change a lightbulb or similar. The mains switch should be labelled and be easy to identify with ‘on’ and ‘off’ clearly visible so you can easily see whether your electrics are currently live or not. 

The circuit breakers

The circuit breakers, also known as MCBs are what switch off a circuit if there is a fault. The electricity on that circuit will suddenly switch off, in order to protect you. MCBs are like a fuse and you’ll find they work on different size Amps depending on the power required, for example, a cooker circuit is likely to need a bigger Amp than a lighting circuit. 

The Residual Current Devices

The Residual Current Devices are for earth faults such as impact to wires, amp leakage etc. When the RCD detects a loss of amps whilst it monitors current, this switches the RCD off, which switches off all the circuits that are being monitored by the residual current devices.

Your trusted electrician in Luton

N & M Electrical service work in homes across Harpenden, Luton, Caddington, Slip End, East Hyde, Tea Green, Harlington, Toddington, Houghton Regis, Dunstable, resolving any electrical issues you might have. To get in touch, you can call us on 01582 932 533, email us at info@nandmes.co.uk or send us a message via our contact form.