rcd tripping

[electric8]

Doing a cu change and ring circuit is tripping the rcd. was working ok before on a non rcd breaker
any ideas what might be causing this.

 

[Octopus]

suggests to me something is plugged in. You mentioned a nail, is someone else doing DIY?

 

[PC Electrics]

Zero what? ie what units are you measuring 'zero' in?

 

[Octopus]

Are you fitting a dual RCD board, if so are all the other circuits OK?

 

[Hawk81]

L-N so why wouldnt the breaker trip

That is not what you told me earlier. You said zero everyway L-N L-E N-E

 

[electric8]

all other circuits ok but a borrowed neutral on landing light was causing rcd to trip so have had to put both lighting circuits on the same side of the board

 

[telectrix]

if it's 0 L/N some load still connected. you need to be more thorough in obtaining readings, then split ring and trace through each leg till you find the fault. could be a borrowed neutral, damaged cable, dodgy connections, cpc not sleeved, trapped wire in fitting. the possibilities are enless.

 

[Hawk81]

all other circuits ok but a borrowed neutral on landing light was causing rcd to trip so have had to put both lighting circuits on the same side of the board

In my opinion this is not the answer to a borrowed neutral. A borrowed neutral is a danger and should be sorted out not ignored.

 

[Octopus]

In my opinion this is not the answer to a borrowed neutral. A borrowed neutral is a danger and should be sorted out not ignored.

And by puttings all the lights on one RCD you're breaking the "rule" about inconvienence (and I know that's not the right term but its Friday and the wine is flowing)

 

[electric8]

problem wont be ignored it will be reported to the customer with recommendation that that it is rectified asap .but i have had to place both lighting circuits on the same rcd as a temporary measure to stop the whole board going off when the landing light was switched on

 

[Hawk81]

problem wont be ignored it will be reported to the customer with recommendation that that it is rectified asap .but i have had to place both lighting circuits on the same rcd as a temporary measure to stop the whole board going off when the landing light was switched on

Fair enough

 

[telectrix]

just to put the record straight, i was working in the 70's and i never, ever installed borrowed neutrals. we weren't all cowboys, even though the regs were written in latin.

 

[PC Electrics]

With the "borrowed neutral at the landing light" situation the very least you should do is put all the lights onto the same MCB. Even if you've put them on one RCD, if they are still on 2 MCBs then you still have the borrowed neutral problem, which is a danger and would be a code 2 on a PIR (see ESC BP guide).

 

[electric8]

still dont understand if ir test shows dead short L-N why would this not trip the breaker

 

[Hawk81]

still dont understand if ir test shows dead short L-N why would this not trip the breaker

Are you sure there is not an FCU with a neon or something like a tv amp in roofspace or smething else plugged in?

 

[electric8]

yes it will be reported to the client and rectified once i have permision