This is probably the most common fault of them all. I often get calls relating to this and last week was no exception. I had a call out to Adderbury where the RCD had tripped, but could not be reset. With a few simple steps you can locate the fault very quickly, depending on what it is of course!
What to do?
First of all go to the consumer unit and switch off all of the miniature circuit breakers (MCB’s) which the RCD is protecting. Reset the RCD and should you be successful and it remains on, switch the miniature circuit breakers on one at a time. If the RCD trips when switching one of the circuits back on, then this is the circuit with the fault. Usually it’s a fault on one of the socket circuits and 9 times out of 10 it will be an appliance plugged into the affected circuit which has caused this.
Unplug all of the appliances!
Physically remove all the plugs from the sockets on the affected socket circuit and switch off any switch fused spurs that may be related to that circuit. You often find switch fused spurs in kitchens which isolate appliances like washing machines, dishwashers, extractors etc. Often switch fused spurs are used for outdoor supplies and pond pumps too.
Now that all the appliances are unplugged and the switch fused spurs are off, try resetting the RCD. Should it remain on, then congratulations you have cleared the fault! Sadly, it looks like you may have to replace one the appliances.
To find the faulty appliance, simply plug them back in one at a time until you find the appliance which trips the RCD.
My RCD still keeps tripping!
If the RCD cannot be reset after trying the procedure above, then you will need an expert to test and locate the fault. Contact me if you require assistance with this matter.
Prevent your RCD tripping
If after reading this you feel concerned and would like to prevent these faults occurring. Then consider a full test and inspection of your fixed installation, also PAT testing (portable appliance testing) maybe something to think about too. Please contact me for more advice.