Fuse board or Consumer unit. What are they?

An old fuse box

You probably have an old 'fuse board' that under your stairs that controls all of the electrical circuits (the lighting and electrical sockets) in your home.
These days we install what are now called 'consumer units' which are much safer and simpler to use. Consumer units use Miniature Circuit Breakers (MCBs) rather than a fuse, MCBs are a switching device so we can switch off a circuit if we need to work on it, also they protect circuits from certain types of electrical fault therefore keeping us safe.

MCBs are also more convenient as if they trip they can be easily be reset as opposed to old rewireable fuses in fuseboards need to be re wire, which can be fiddly especially if the lights have gone out and you're trying to do it by torch light! different circuits are protected by different rated MCBs Lighting circuits are generally protected a 6Amp MCB and sockets by 32Amp, showers and cookers are protected by 45Amp MCBs other circuits such as a heater are protected by 16Amp or 20 Amp MCBs.

A new Consumer unit

New consumer units also use a Residual Current Devices (RCD) which trip under certain fault conditions, RCDs are great and save lives you may remember advice that if you are using electrical equipment outside then you should use an RCD unit that you plug into a socket and then plug the equipment into the unit. In recent years the electrical regulations have changed to say that all circuits in a home have to be protected by an RCD. RCDs can be Identified by a 'T' or test button on them, RCDs should be tested by pressing the 'T' button on a regular basis every 3 months.

New consumer units have a big red switch on them this is the main switch this switch controls every circuit that  is covered by the new consumer unit switching it off will cut all power to every circuit.
Regardless of whether you have a fuseboard or consumer unit every circuit/ fuse or breaker should be labeled as to it's function so that if you need to turn it off you won't need to turn off every circuit. With a fuse board if the upstairs sockets trip out you can locate the correct fuse easily to be able to rewire it.

Regards

Paul
Hertford Electrician