Ring Main fault

[sparky928]

Had a call this Morning that her rcd keeps tripping.


So i went round there First of all unplugged everything still tripping. Done a few tests L-E N-E L-N and end to end test all came back as 0 mohms.

So i Separated the legs at both the board and the sockets found the fault leg.

Reconnected the good leg got a good part of the sockets working.
So i went upstairs as the cables are coming down to the sockets and the room above is the bathroom with vinyl flooring. She didnt want me to the lift the floor up without speaking to her husband.
.
And then the customer tells me that a few months back they had a leak in the bathroom.

i was thinking water probably got in the junction box.

By why didnt it trip a few months back?

 

[Darkwood]

Welcome to the Forum Sparky928

In reply - Your guess is as good as our until you get to the joint or damaged cable we all can only guess.

 

[snowhead]

By why didnt it trip a few months back?

Has the customer said it definitely hasn't ever tripped?

It May have tripped and reset O.K after the leak was repaired.
They may have another leak.
It might be a dead Rat.

 

[sparky928]

Never tripped recently. Last time it tripped was 15 years ago she reckons

 

[Darkwood]

I would find the joist run direction and take a board up in an adjacent room to see if you can see across under the bathroom.. the actual fault may not be under the bathroom, it may just seem its likely to be there. Also see if the bath panel comes off and you have access under the floor beneath the bath.

 

[alanl]

A water/wet connections fault wont give 0Mohms.
Test your probes in a bit of water to see the readings.

 

[Darkwood]

A water/wet connections fault wont give 0Mohms.
Test your probes in a bit of water to see the readings.

It may if its been arcing and created a carbon track in the material