Intermittent Ring Main Fault due to Bad Weather

[ddp01]

I have an intermittent tripping fault on a 30amp ring main circuit (old Wylex board with B-Breakers - No RCD) located in single storey extension (no roof access) caused by the bad rain within the last 24 hours. The tripping can be sometimes instant, but other times it can last as long as a couple of hours; with more wet weather on the way I know it will become more regular. I have checked the sockets and a visible junction box and there are no wet or bad connections.

I know there's a short caused by a leak in the ceiling somewhere, which means pulling down parts of that ceiling looking for it. Before I go down that route, is there a way of testing for the location of the fault so that I won't cause so much damage looking for it?

 

[a12jpm]

Tester out, split ring then test, split,test,split until you find between which 2 sockets.

Then large hammer/jab saw and make holes.

 

[ddp01]

My thanks for the tip.

 

[Marnik]

Any outside lights?

 

[ddp01]

No outside lights or sockets. This is an existing installation from the late 80's/early 90's. A complete re-wire would be nice, but I was told that was not an option.

I know there must be a junction box somewhere that is causing the problem with the wet weather, but the only wet patch in the ceiling that I can see is not near any of the sockets, nor is it in any logical line of sight with the route of the ring main circuit. (I am guessing here.)

 

[ashrow]

Water flows where it wants (except uphill)
Split the ring and test from socket to socket (like mentioned before)
You will find it and then only damage a smaller part of the ceiling

 

[ddp01]

Thanks for your input.

 

[Marnik]

Sorry, did not read your post correctly.you mentioned a wet patch on the ceiling? No access to roof space?
Well in that case you have to try and figure out where the water is travelling from (not easy!) Had this problem once before, and solved it
using a spirit level on the underside of the ceiling to determine the way the water would travel. But this method does not give guarantees.
So good luck.

 

[ddp01]

I will try that method too. The trouble with this job is that it's for a friend and where I live friends expect things for next to nothing, but something tells me that this job is going to get pricey!! I am wondering whether to back off and let an independant electrician do the job (just to save the hassle).

 

[ruston]

Has this extension got a flat roof? if so that could be the problem. Get a roofer to have a look for water ingress. sort that and the problem may go away.

 

[ddp01]

No, it's an apex. That said, I suggested a roofer to have look at the flashing, tiles and so forth to get rid of the cause of the problem, before I find and fix the fault.

 

[ruston]

Thats where I would be starting, where else can the rain water come from ; unless you have plumbing in the void. If it is rain related its got to be the roof or flashings in my opinion.

 

[ddp01]

No plumbing, just the leaking roof...

 

[ruston]

Sort the leak and the fault will probably dry out. I once had a JB filling up with water once, when it got to terminal level it popped . It was water down the cavity flooding under floor.