Red Kite Electrical, Advice and tips about your electrics

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Advice and Tips about electrics

The RCD (the wide switch with the test button) or circuit breaker (the narrow switch with no button) on my consumer unit has tripped - what do I do next?

The trip has occured because one of these breakers is detecting a fault somewhere in your electrics. This is sometimes called "nuisance" tripping, because you were not aware that anything was wrong. Where is the problem? It is often difficult to determine, but there are some simple steps to take before you call in Red Kite Electrical. Here is how to proceed;

  1. Determine whether the rcd or the individual circuit breaker has tripped.
  2. If it is the circuit breaker attempt to reset it (turn it back on). It may well successfully reset. You will probably find that a lamp (bulb in English) has blown somewhere on the particular circuit. This is not a fault with the breaker. In fact it proves the breaker is working effectively to keep you safe. When a lamp blows, the filament inside breaks. When this happens one side of the filament will still be connected to the electrical supply. As this charged part of the filment drops it may touch part of the metal base of the lamp. This creates, for a moment, a short circuit (a huge damaging flow of current). It is this the breaker detects, and trips to protect the circuit. By the time you reset the breaker the filament will almost certainly have burnt away because of the short circuit, solving the problem. Don't forget to open the switch (switch off) when you change the lamp.
  3. If the breaker will not reset, open all the switches (switch off) if it is a light circuit, or dedicated circuit (cooker, boiler, immersion etc). If it is a socket circuit, remove all the appliances. Try again to reset.
  4. If the breaker now resets, close all switches (switch on), or plug in appliances in turn. If a particular light fitting again causes the trip, open its switch, and leave it open. You can then reset the breaker and use the other light fittings on that circuit. Call Red Kite Electrical to investigate the problem. If a particular appliance causes the trip discard the appliance.
  5. If the breaker will still not reset, call Red Kite Electrical.
  6. If it is the rcd that has tripped open all the breakers protected by the rcd. Hopefully which circuit breakers this is, is clear from the labels on the cover of your consumer unit. If it is not the relevant circuit breakers will be those to one side or the other of the rcd (unfortunately it is not possible to say which as different manufacturers have different layouts for their boards). If you are unsure open all the breakers -but have a torch handy if it is dark.
  7. Attempt to reset the rcd. If the rcd will not reset with all the breakers open call Red Kite Electrical. But be aware that some manufacturer's rcd's (such as MK brand) have a mid-position. After a trip the rcd's switch will be in the mid position. To reset you must move the switch to manually to fully open. You can then close the switch.
  8. If the rcd stays reset, close all the circuits in turn.
  9. You will probably find that one of them causes the RCD to trip again. You have now isolated the likely cause of your problem to a particular circuit. Follow steps 3, 4 and 5 above to attempt to isolate the fault further within that circuit. If it proves impossible to isolate the cause to an removable appliance call Red Kite Electrical. Clapped out fridges, freezers, hairdryers, vacuum cleaners and anything else with electric motors inside them are notorious causes of tripping in rcd's. So make sure you have disconnected them when attempting to isolate the fault. When the faulty appliance is re-connected the trip will occur again. Get rid of it!


These tips are NOT intended to substitute for a full investigation by a competent, qualified professional. They are provided as common sense advice for householders to determine if you need to call a professional. If you are in any doubt please leave the RCD off and call Red Kite Electrical.

On no account remove the cover of your consumer unit, or switch or socket outlet. Do not get involved in touching the fixed wiring. Please call Red Kite Electrical to resolve any problems that involve getting inside electrical enclosures.

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