New downstairs light fitting tripping upstairs circuit.

[ban-all-sheds]

What happens if you put a plug on it (3A or 5A fuse) and plug it in - does it still trip the RCD?

 

[EFLImpudence]

Also, can we have a cleare picture of th CU, please?

I think you have stated that what trips is the RCD but you describe this as the upstairs lights tripping.

Are not the downstairs and upstairs lights on what appears to be the NON RCD side of the board (even though both sides are labelled in green)?

I've just noticed you have two main switches so goodness knows how it is wired.
It appears that a second RCD has been replaced with the second main switch which may indicate that someone has previously given up trying to find a fault.

 

[MikeJEN]

I will take another CU pic tonight.

I think the downstairs trips are on the left of the RCD and the upstairs trips are on the right of the RCD. As to the NON-RCD side of the board...i don't know, I'm just a novice.

So it's not usual to have four of the red trips?? I had an electrical circuits condition report before moving in...shouldn't something like this have been brought to my attention??

I think when I tried to fit the new fitting the RCD and the upstairs light (to the right of the RCD) both tripped. To be honest I was very P***** off it wasn't working so can't exactly remember. I'll have another go tonight.

Mike

 

[ban-all-sheds]

I think the downstairs trips are on the left of the RCD and the upstairs trips are on the right of the RCD. As to the NON-RCD side of the board...i don't know, I'm just a novice.

The non-RCD side is to the right of the RCD.

So it's not usual to have four of the red trips??

That's two, not four, and it is very unusual. EFLIs theory is probably correct - there used to be 2 RCDs, one to the left of the right-most main switch, covering the circuits to its left, up to the 2nd (now only) RCD, but some incompetent idiot removed one because he could not find a fault which kept tripping it.

I had an electrical circuits condition report before moving in...shouldn't something like this have been brought to my attention??

Yes.

Was it a proper inspection and report done by a real qualified electrician?

I think when I tried to fit the new fitting the RCD and the upstairs light (to the right of the RCD) both tripped.

1) If the MCB is tripping, it's not a N-E fault, it's L-E or L-N.

2) No circuit to the right of the RCD should cause the RCD to trip, as they are not connected to it. If one is making it trip then somewhere downstream you have a connection between the circuit to the right and one to the left.

 

[MikeJEN]

As far as I know he was a qualified electrician...I am waiting for him to call me back so i can discuss the two main switches!

I think the bottom line here is I don't think this is something I will be able to diagnose and resolve myself so think I'll just bite the bullet and call a professional in. Can anyone recommend a reputable firm/person in North London/herts area?

Also, I know it is hard to say until fully identified what the problem is but is it likely to be a simple fix or am i looking at something serious in terms of £££?

Thanks
Mike

 

[EFLImpudence]

I think the bottom line here is I don't think this is something I will be able to diagnose and resolve myself so think I'll just bite the bullet and call a professional in.

It seems to be getting that way.

Can anyone recommend a reputable firm/person in North London/herts area?

Not foolproof but -
http://www.competentperson.co.uk/

Also, I know it is hard to say until fully identified what the problem is but is it likely to be a simple fix or am i looking at something serious in terms of £££?

Quite.

 

[MikeJEN]

Morning all...a quick update. I bought a multimeter and tested the new light fitting...all no readings except for the connection between L-N, which on the lowest resistance setting (200 ohms)had a reading of 90...is that enough to trip the CU or is an expected resistance number.

Cheers
Mike

 

[JohnW2]

Morning all...a quick update. I bought a multimeter and tested the new light fitting...all no readings except for the connection between L-N, which on the lowest resistance setting (200 ohms)had a reading of 90...

Did you have a lamp ('bulb') in the fitting when you did those measurements? If so, measure the L-N again without a lamp.

Kind Regards, John