Some properties have a main electric switch with a device called a Residual Current Circuit Breaker (RCD). This is a large switch, marked on/off as shown in the diagram. This switches the electricity off as soon as it detects a fault.

Residual Current Circuit Breaker (RCD)

Some properties also have smaller switches instead of fuses for each circuit. These are Miniature Circuit Breakers (MCB’s). If a circuit is overloaded or a fault develops, the MCB protecting that circuit will automatically switch off the electricity. To identify the source of the problem, you should:

  1. Switch off all the MCB switches (see picture above).

  2. Return the RCD switch to the “On”

  3. Switch on each MCB in turn until the RCD switches off. This will tell you which circuit the problem is on.

  4. Switch off and unplug all appliances connected to that circuit. Switch the MCB and RCD to “On”. Plug in and turn on each appliance in turn, until the MCB switches off. This will tell you which appliance is at fault.

If either the RCD or the MCB switches will not return to the “On” position, there may be a fault with the wiring. We will need to send an electrician to attend to this.


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