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Rcd keeps tripping

For the last 2 weeks or so every time we use the oven it trips the 100 MA RCD. We've had a couple of electricians come out to look at the problem, but I don't know if we are close to a solution. One has checked the oven itself and the isolator switch next to the oven and found no issue, so where I have seen a lot of posts commenting on the oven element being the issue, I would assume that's not the problem if he has checked both of these? Also, once the oven has tripped the RCD, we are able to get power back on by leaving the fuse for the oven off, but then gone to use a hairdryer upstairs, which trips the RCD again. Using the hairdryer does not trip the circuit if we haven't already attempted to use the oven. Furthermore, it seems like if we leave the power off for an hour or so after the oven has tripped the circuit then we can switch everything except the oven back on and use everything else as normal. Any ideas what the issue is? One electrician has suggested the RCD may be overloaded and is going to upgrade the consumer unit and replace the existing RCD with more than one to balance the flow. Does this seem reasonable?

3 Answers from MyBuilder Electricians

Best Answer

The problem we have these days is that there are decent qualified competent electricians out there but just as many unqualified not competent people who think they know what they are doing and just advertise in the paper as electricians. Im not saying that has happened in your case but just to be aware and check they are registered so they can inspect and test properly and issue revevant paperwork on the work that is carried out (if required) and carry work out to meet standards.

Its always difficult to try diagnose without seeing the job but straight away what i would be doing is a pat test on the cooker and if thats fine then testing the oven element and to do this generally the back plate inside the oven would need to be removed, the element unplugged and and then testing it for continuity, this is not a job you can just test at a socket you physically need to remove to test and have a look at it. There are generally 2 elements which is a grill element and a oven element but this is depending on type of oven and can sometimes differ. A quick test you can do if you have a fan assisted oven is turn the fan on but keep the temperature at 0, if the fan kicks in and the rcd doesnt trip then turn the temperature dial up to 50 and check if the red light comes on, if it does then the rcd trips it will be the element. The reason for this is you have tested the cooker by turning it on and the rcd is ok, so that would generally tell you there is no earth leakage with the actual cooker its self then if you do the steps above and it trips once you have asked the cooker to call for heat then the reason for that is the element which is just like a coil has failed so instead of the electrity being able to flow freely all around that coil when it hits the failed part you will have some leakage which is why the rcd trips. The hairdyer again is a different issue but could be something as simple as you carry out a pat test and it fails.

Its quite easy for anyone to say you need a new consumer unit but before we get to that point i would be expecting to see quite a few tests being carried out one of which would be a ramp test i myself have been out to similar jobs which had previously been attended by someone else and at guess work the customer had been advised by that person they need a new consumer unit who then fitted it and the faults were still there, which also proves that person hadnt tested as required once fitted or they would have found the fault. I was then called to investigate and once i diagnosed the fault it was nothing to do with the board at all so hence what i said about using experienced competent electricians.

Hope this helps.


Answered 30th Apr 2015

OMG, your oven has an earth leak. In other words live feed is leaking to the outside casing. Your hairdryer is on the verge of the same thing.
Answer..... Bin both and buy new ones.


Answered 6th May 2015

Oven element is definitely part of the fault. Which needs testing correctly. Also I would ramp test the RCD to find out how much current is required for it to operate. Seems you need to source a more qualified experienced electrician.


Answered 29th Apr 2015

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