In most cases, if you have an electrical fault in your home, the corresponding circuit breaker will trip in your consumer unit and power to that section is cut. In more severe cases and depending on your switchboard (fuse box), then the whole property’s electricity will cut out leaving you with no power at all.

In these circumstances quickly identifying the source of an electrical fault can be crucial to your safety. Learning how to isolate an electrical fault in a switch or appliance can mean you can make it safe and still have power to the rest of your home or business until an electrician arrives to fix the issue.

Consumer Unit Safety Checks

Before running around checking switches and appliances and turning the power back on to try similar tests, start with your Switchboard. Open the door on your Switchboard. Identify the RCD switch (safety switch), it may be labelled as ‘RCD’ and should have a button marked ‘T’ or ‘Test’ above it. Push the test button – this button will check the mechanism operates freely and should cause the RCD to turn the electricity off.

If one of the safety switches is already off and has been tripped, then this should give you a clue as to what or where in your property is causing the problem. Turning it back on will either make it trip again immediately or not, depending on what the circumstances were when it tripped to begin with, turning it back on and it staying on is not that wise as now your power is in a dangerous state. Depending on the safety features of your consumer unit you now have some risks.

If you suspect a particular appliance or switch then unplug everything on that circuit before turning it back on. If it doesn’t trip, then you can slowly turn items back on (that will actually draw power) one at a time to see what causes the power to trip. Most often it will be a faulty appliance, so by process of elimination, you can isolate which one. Sometimes it’s not the appliance but the socket or wiring, plugging the suspected appliance into another socket may stop the safety switch tripping telling you it’s a switch or socket on a particular circuit. At least then you can call an electrician and narrow down the problem for them and allow your home or business to operate as normal until they arrive.

No Power At All

If your Safety switch constantly trips completely (the master switch) or the same individual circuit switch just keeps tripping then you should call an electrician immediately as there will be little you can do.

If you suspect something in particular then you can always unplug this completely and try restoring power again. If you can remember what was happening at the exact moment power was lost this might also help.

Common Causes Why Power Switches Trip

  • Faulty or damaged appliance
  • Damaged wiring
  • Overloads (too many appliances running in total)
  • Bad weather
  • Defective safety switches

Ultimately you should always consider your safety first, so if you don’t think you can isolate the cause then just call an electrician right away. you’ll need to call an electrician almost certainly unless it’s a faulty toaster that can be replaced, but you can save a lot of inconvenience by testing via your switchboard to isolate the problem.