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.

 

[i=p/u]

leakage

 

[Octopus]

what have you got plugged in? What were the IR readings like? Presumably you're fitting a dual RCD board - are you sure that you've got the neutrals in the correct bars?

 

[electric8]

cant find any thing pluged in just done ir got zero reading

 

[electric8]

what does this mean

 

[Guest123]

Borrowed neutral on lighting circuits, crossed neutrals on ring finals.

Was any RCD protection present beforehand???

 

[Hawk81]

cant find any thing pluged in just done ir got zero reading

More info would be helpful. what readings were zero? live to earth? Live to neutral? neutral to earth?

 

[Hawk81]

what does this mean

If you do not understand a simple IR test result should you really be doing a CU change?

 

[electric8]

all readings are zero ?????

 

[Hawk81]

It means you have to split the ring and test and split and test until you find the cause. can be a long and boring process. Sounds like a damaged cable. I do not know how if it is zero everyway how it worked before.

 

[electric8]

i understand how to do an ir test i just dont understand that if there is a dead short why was the breaker not tripping out before

 

[Octopus]

cant find any thing pluged in just done ir got zero reading

Zero - between what?

 

[electric8]

yes thanks thats what i thought any ideas what might be the cause ? nail through the cable ???

 

[Octopus]

yes thanks thats what i thought any ideas what might be the cause ? nail through the cable ???

I think you misunderstood my question.

Your zero reading - between what? i.e. L-N?, L-E?, N-E?

 

[electric8]

L-N so why wouldnt the breaker trip

 

[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