Strange Fault

[steviez]

Hi,

I have been Investigating a fault in my house today and have really hit a brick wall.... The RCD is tripping and now will not turn back on at all. I have removed each cable from the box one by one as a process of elimination and still it happens. The stranger part is this: the earth's and neutrals seem to show as live using a volt stick and show between 120v and 230v on a multi meter.. this is also happening when EVERYTHING is removed from the board and just one temp socket is in place for testing. Its a new(ish) contactum split load board in plastic.

I have no idea why this would be happening unless it has to do with the fact the the house only have a 6mm earth going in to the ground out side.

Any ideas?

Thanks

 

[Alarm]

Put the volt stick away.
Walk away from the mess you have made.

Call someone qualified.

 

[cajar]

If you read voltage on your cables with your supply cut off then it must be coming from another source - presuming this is the only consumer unit in your house, could any of your wiring come into contact with a neighbours? (thinking outdoor security lights or cables to the shed?)

 

[steviez]

If you read voltage on your cables with your supply cut off then it must be coming from another source - presuming this is the only consumer unit in your house, could any of your wiring come into contact with a neighbours? (thinking outdoor security lights or cables to the shed?)

Its not there when the power is off.. only when power in applied to the circuit. its onyl a small 1 bed house with 1 socket in each room so I have removed everything from the board and put a test socket in and the same is still happening.

 

[obiplumbkinobi]

Do as Alarm says

Get a qualified electrician in!

 

[steviez]

Do as Alarm says

Get a qualified electrician in!

I cannot afford... I am part one qualified and have worked in the electrical trade for over 6 years so I know what not to do etc. Im just stuck on this fault

 

[DetlefSchmitz]

Hi,
the earth's and neutrals ... show between 120v and 230v on a multi meter.. this is also happening when EVERYTHING is removed from the board and just one temp socket is in place for testing.

...between where and where?

 

[Taylortwocities]

I have no idea why this would be happening unless it has to do with the fact the the house only have a 6mm earth going in to the ground out side.

So your supply type is TT, yes?

The size of the earth conductor will have NO influence on this problem.

When did this start happening? Was it all of a sudden in the middle of the night, or was it after some electrical, or other works were being undertaken.

 

[1550]

Fair enough- Have you paired the neutrals on the rcd side accurately?

 

[steviez]

...between where and where?

I cant remember now as it was this morning I did it but I think it was between neutral and earth.

So your supply type is TT, yes?

The size of the earth conductor will have NO influence on this problem.

When did this start happening? Was it all of a sudden in the middle of the night, or was it after some electrical, or other works were being undertaken.

It started happening a few days ago for no reason but the RCD would always turn back on and now it wont. Its due to be rewired as we have found several cables that have been eaten by the old rats. This is the reason I though the RCD was tripping but now it wont even work with just the test socket on

Fair enough- Have you paired the neutrals on the rcd side accurately?

Yes they are all in the correct side.

 

[obiplumbkinobi]

Sorry didn't mean to be rude, I am no electrician myself,I am currently studying eal level 2, 17th edition and 2392, and after that 2391 and I wouldn't consider myself an electrician after all that.

I think there are far better people here than me to answer your question.

I just think that sometimes you should stop and call in the experts when (but mainly, before) your'e in over your head.

Waffle over

 

[steviez]

Sorry didn't mean to be rude, I am no electrician myself,I am currently studying eal level 2, 17th edition and 2392, and after that 2391 and I wouldn't consider myself an electrician after all that.

I think there are far better people here than me to answer your question.

I just think that sometimes you should stop and call in the experts when (but mainly, before) your'e in over your head.

Waffle over

Totally under-stud and if I could afford it I would.

 

[1550]

Take the individual circuits out and replace them one at a time ,see if the rcd holds after you apply each circuit. LN and E , thats the easiest way if you have no gear . You may have a borrowed N , but that should have showed before now.

 

[steviez]

Take the individual circuits out and replace them one at a time ,see if the rcd holds after you apply each circuit. LN and E , thats the easiest way if you have no gear . You may have a borrowed N , but that should have showed before now.

Done that, the CU is now empty apart from the tester socket I have in and yet the fault is still there. When power is applied to the live side the neutral and earth becomes live. If i remove the earth the RCD trips still but if i remove the neutral it does not trip anymore.

 

[1550]

Take the tester out and remove that circuit, re-apply the others and see if it holds.