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Rcd tripping out

Hi, I have had a few episodes of RCD tripping in the last 12 months and have never found an obvious cause. I had unplugged most appliances in the house, leaving only the fridge freezer, wifi router, telephone and CCTV system on in the house when I am away. On 3 occasions it has tripped while I have been away and the alarm went off. I am at a loss as to what could be the cause. . As far as I can see, the entire CD trips and not just one fuse. Any guidance on what to check for would be greatly appreciated.

Kind regards,

6 Answers from MyBuilder Electricians

Best Answer

Because the RCD trips occasionally unplugging devices a lot of time doesn't help. What helps most time in this occasions is for your electrician to do an RCD test and if the results come fine then do an Insulation Resistance test on your circuits. All most every time tricky faults like this can come out with this test. Be prepared though, a circuit(s) rewire may needed. Just ordering a Condition Report might not solve your problem. One, because not every time the electrician will do an Insulation Resistant test, that's not necessary wrong because with EICRs you do only what tests have beeb agreed (sometime are just visuals). And two, when an electrician does a Condition Report, any faults that been found unless they is an immediate danger won't be rectified as that's not the purpose of it. So you may ended up spending money for things that won't help. Better call an electrician to find the fault and after that you can get a Condition Report if you wish or is necessary.


Answered 25th Jul 2017

Possibly a neutral to earth fault.
Physically unplug - not just turn off appliances (not all sockets are double pole and so only switch the line and not neutral, a fused spur will though)
Think about what is getting wet or damp. Outside lights? Disconnect the line and neutral. Conservatory damp ingress? Damaged outside cable to garage, shed? In-floor sockets wet?
Otherwise its an electrician to ramp test the RCD and perform insulation resistance tests.
Hope this helps.


Answered 26th Jul 2017

Good Evening, The approach is to remove (disconnect) as many electrical appliances from the circuit as possible and then connect them back into the circuit one at a time. The faulty appliance will cause the RCD to trip; this shows which appliance is faulty (causing the RCD to trip).

After unplugging all appliances, or turning them off, see if the RCD will reset. If the RCD will reset, the fault is with one of the appliances; if the RCD trips again the fault is with the electrical circuit – call a qualified electrician.

Hope this helped


Answered 24th Jul 2017

Hi, this could be a number of things,
•faulty appliance.
•earth leakage.
•faulty rcd.
Certain appliances with heating elements can be more prone to earth leakage. Best thing to do Is make sure you un-plug all appliances (not just turn off at switch) this is because if you get a single pole socket the neutral won't be switched off. Then turn all mcbs back on 1 by one followed by appliances, when the rcd trips it's that appliance that is faulty. My guess would be your fridge freezer, If tripping continues you need an electrician out to do various tests and route deeper into finding the problem, thanks.


Answered 24th Jul 2017


There are a number of reasons as to why your RCD would trip. Here are a few you may not of necessarily thought about.

1- You may have too many circuits on the RCD within the consumer unit (An excessive amount of appliances, lights and devices would produce a high earth leakage value which may be higher than the m/A rating on the RCD) LED lamps are known to cause this type of problem.
2- It may not be your sockets that are tripping the RCD, outside lights that aren't fully watertight are very common culprits when nuisance tripping occurs. It may also be worth your while to look for dampness behind appliances, in walls close to electrical accessories and under floorboards where pipework is present.
3- High resistance on your neutral conductor. Possible damaged cable or cables put under strain/pressure beneath floorboards.

If you are in doubt, call an electrician. Make sure they are registered with an electrical organisation such as NAPIT or NICEIC. They should be able to identify any faulty wiring through testing each circuit.


Answered 27th Jul 2017

I would recommend an electrical inspection this will either identify or rule out any faulty wiring, at the same time a test can be carried out to the RCD to see if it is faulty, too sensitive or ok which would then rule out the installation as the cause


Answered 25th Jul 2017

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