RCD, ring to lights fault ?????

[sonobit]

Hi guys, got a testing problem for you mate of mine was cutting some heating pipes and said he got a belt of one of the pipes, so he turned of the power and finished cutting pipe, he turned power on when he finished and the rcd tripped, he called me, i located the problem to a dead short on upstairs ring, so i split the ring and tried narrowing down the fault, now hears the mystery one upstairs s/o has the lives, live when ring is on, but when upstairs lights are on both neutrals to the s/o are live! no other neutrals on the upstairs ring are live. and the rcd only trips when an appliance is plugged in, but not when my socket and see is plugged in and both green lights come on! its taken me now ages to pin point this exact fault, ive tested all the legs on the ring seperate and theyre fine. im about to tear up the floors and run a new ring..........any ideas people....by the way its a split board ring on rcd side, lights on non rcd side

 

[WayneL]

Hi guys, got a testing problem for you mate of mine was cutting some heating pipes and said he got a belt of one of the pipes, so he turned of the power and finished cutting pipe, he turned power on when he finished and the rcd tripped, he called me, i located the problem to a dead short on upstairs ring, so i split the ring and tried narrowing down the fault, now hears the mystery one upstairs s/o has the lives, live when ring is on, but when upstairs lights are on both neutrals to the s/o are live! no other neutrals on the upstairs ring are live. and the rcd only trips when an appliance is plugged in, but not when my socket and see is plugged in and both green lights come on! its taken me now ages to pin point this exact fault, ive tested all the legs on the ring seperate and theyre fine. im about to tear up the floors and run a new ring..........any ideas people....by the way its a split board ring on rcd side, lights on non rcd side

Sorry, mate,

I've read this three times now to try to help you, and I can't make out what you are going on about.

Did you read it again yourself?

You need to explain it clearer and use punctuation.

Not taking the p**s, mate, just baffled.

 

[Sintra]

Have to agree with Wayne it's not very clear.

 

[sonobit]

yeah i know its a bit screwed up but bascially theres a dead short on the upstairs ring, which i believe is coming from ...somehow the upstairs lights through the neutrals . hope that is a bit clearer. its areal nightmare im thinking my tester is knackered one minute, then next the RCD....

 

[robsparx]

I dont quite understand that, but could somebody have borrowed a neutral for the lights off the ring circuit?!

 

[confused-fuse]

i would go in loft find the lighting loops and check there make sure no rodent as been chewing the cables first.. then go un-tag N from feed and find the fault that way or start lifting floorboards and see where the short... what meter readings are you getting ???? at ccu with cables off mcb ??

 

[HRL]

Sounds like a sharred neutral to me.... That'll be nice to find i'm sure...

 

[cobbydale]

has someone linked the upstairs light with the s/o?

 

[sonobit]

spoke to customer about lifting the floors, and basically its a no go...... (typical fix my electric... but dont make a mess).

So ive had to split into 2 radials and covered in the faulty socket.

I waS getting 0 Mohms for IR on upstairs lights and on upstairs ring, but when i completely disconnected the faulty socket and the 2 sockets either side IR was fine on existing legs and on lights.
So thats what ive had to do, but its annoying i cant rip up floors and get to bottom of it.

To make it all worse the guy moaned...." so why cant i use that socket, it worked fine yesterday, so how has that changed?...." i felt like telling him to grab the live neutrals and see why they have to be dissconnected!

somehow i think upstairs lights live was contacting the ring main neutral......but guess now ill never know how.

Cheers anyway though guys, its always hard trying to explain a fault without being there.

 

[m25maintenance]

mate where is the job. it is very possiable a screw is going tru cables from the 2 circuits. i had a job like that a bit back. also when u av broke the ring up seperate all ring legs and seperate all conductors, try continuity test between all conductors, if the cable is good then u should get open circuit.

 

[m25maintenance]

also mate ask that plumber what he has been doing, he might av drove a screw into cables thus line earth fault giving him a belt on the bonded pipes

 

[m25maintenance]

ask d plumber did he drive any screws into floors

 

[cbw]

I am also going the plumber route!