Stair Circuit Tripping RCD

[Dave W]

Evening All,

Installed a new dual RCD CU today, all dead tests were ok however once live everythings fine until the landing light's switched on and BOTH RCD's trip, anyone experianced this before, any suggestions anyone ?

 

[onions1066]

Borrowed neutral by the sounds of it. Did you carry Out a eicr before swapping the board?

 

[Flanders]

shared neutral

 

[Sintra]

Borrowed neutral that's a cert.

 

[MDJ]

Evening All,

Installed a new dual RCD CU today, all dead tests were ok however once live everythings fine until the landing light's switched on and BOTH RCD's trip, anyone experianced this before, any suggestions anyone ?

What do you mean has anyone experienced an Rcd tripping before? the answer to your question is a shared neutral between the downstairs and upstairs lights. You obviously have the 2 lighting circuits over the 2 Rcds and the shared neutral ensures the trips go. I thought any spark with any knowledge would understand this. If you are not an electrician my profound apologies.

 

[Flanders]

You can put both lighting circuits on same RCD but this does not solve the shared neutral problem

 

[MDJ]

Jeez, 3 replies whilst I am typing my reply, fast work fellas

 

[onions1066]

You can put both lighting circuits on same RCD but this does not solve the shared neutral problem

You mean on the same mcb not rcd?

 

[Flanders]

I think this question should be in the top 10

 

[snowhead]

I think this question should be in the top 10

I think this question should never be asked.

 

[Flanders]

You mean on the same mcb not rcd?

Its a dual RCD board so what I meant was put both circuits on the same side of one of the RCDs you could put them on the same MCB .But I would still keep the circuits separate and sort the borrowed neutral out

 

[MDJ]

Its a dual RCD board so what I meant was put both circuits on the same side of one of the RCDs you could put them on the same MCB .But I would still keep the circuits separate and sort the borrowed neutral out

No that won't work, if you have 2 circuits sharing a neutral you need to ensure the phase conductors to both circuits share the same over current protective device fella, think about it.

 

[DJ Ovengloves]

I suspect he means the same RCD which will stop the tripping if the neutral a are both on the same side of the board. However, the cowboy method of putting both circuits on the same MCB would actually be safer than the current situation....if you can't be arsed to fix the problem properly of course.

You can put both lighting circuits on same RCD but this does not solve the shared neutral problem

You mean on the same mcb not rcd?

 

[MDJ]

Yes it is a cowboy method, I agree 100% with you Fella, but that said although an appalling result, better than connecting to 2 different MCBs. Your right though it needs sorting out.

 

[Flanders]

Yes I agree sorry never made myself clear I would only put on to separate MCBs if I had sorted the borrowed neutral, But then of course with the borrowed neutral sorted out you could go back to using both RCDs :rolleyes4::rolleyes4: As said the cowboy method is an easier fix though