# RCD problems



## LD2520 (Aug 17, 2013)

hi guys me again

I have completely rewired a house recently. Just recently had a phone call from them and the rcd that controls the downstairs keeps tripping. 

I IR tested all the circuits and all were well above the minimum (>2Mohms on a fluke tester)

I'm at a big loss of what to do. The system was all working for a few weeks. Now it keeps tripping. ive tried it with each MCB off to try and locate the circuit but cant get the RCD to stay on. I have tested the RCD and it passes all of its tests 0 degrees and 180. 

it tripped the first time when the oven was put on but now it just keeps tripping with any load on. the only time it stays on is with all the MCBs off but the RCD on.


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## Sledgehammer (Jun 2, 2013)

N-E fault it would seem. IR to identify the issue, break down the circuits individually.


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## great68 (Dec 31, 2012)

3rd post down & its from Jan 
Oh well I suppose there is a good few UK sparky forums now

Anyhow I agree with sledgehammer its a N-E fault so each N would have to be removed from the board and all lamps/devices removed from the circuit being tested but if it hasn't been fixed by now it never will be :laughing:


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## LD2520 (Aug 17, 2013)

Turned out homeowners other half knew best and decided that he wanted to use old oven. Wired it up to 45 amp fused socket but new cooker needed 10mm cable he had wired the old 6mm cable into the fuse and it was causing it to trip. Swapped oven back and no further problems.


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## great68 (Dec 31, 2012)

Hi LD2520, from this and other threads i guess you have not been doing this job long ? Have you got any qualifications or experience yet ? 
The reasons i say this is your reply above and replies on other threads are just not correct. There is no such device as a 45A fused socket and using 6mm instead of 10mm for this would not trip a RCD. As with your socket thread there was a N-E fault. In this case that was either in the old oven or the way it was connected, not for the reasons you have given.


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## LD2520 (Aug 17, 2013)

I am qualified, but no I haven't been doing this long. Trying to gain experience and cant afford to do an apprenticeship. I am looking for a role to help me gain the experience and work towards my NVQ level 3.

As for the "45A fused socket" sorry about that, id been up since 0300. What I meant was 45A fused cooker switch and socket (as found below)

http://www.meteorelectrical.com/4mm...untry_id=222&gclid=COay-PDpw7kCFXQftAodDGQAvw

and the cable must have been faulty but swapping this has worked and there has been no problems since. I don't have a PAT tester and I'm not qualified to use one. But I did take the back off the oven carry out a visual inspection of all cables and a continuity test of the elements. This was so I knew I had done everything to make sure it was safe to use and leave with the customer.


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## great68 (Dec 31, 2012)

Thats fine, as long as you realise an undersized cable in its self will not trip an rcd.


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