Neutral lighting wire

[john2k]

Can anyone tell me if the lighting circuit for my first floor is all on 1 MCB then does the mean they all share a same neutral wire? Reason I ask is because I am installing a Smart WiFi light switch that requires a neutral cable. I am able to get a neutral cable to the light switch from another light pendant in the passage which is on the same MCB, will this work or do I have to bring the neutral back from the actual light that the switch is going to control?

 

[John D v2.0]

Do you have RCDs in your consumer unit? Are the lighting circuits on different RCDs? If yes to both, then they are the same neutral.
If not, it should be but impossible to be 100% without testing it. sometimes the landing light if it has 2 way switching is on the downstairs live and upstairs neutral, but that wouldn't cause you an issue.

 

[ban-all-sheds]

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[sparkwright]

Do you have RCDs in your consumer unit? Are the lighting circuits on different RCDs? If yes to both, then they are the same neutral.

If the lighting circuits are on different circuits, I don't consider that the 'same' neutral.

 

[sparkwright]

If you really only have one true lighting circuit, then you can obtain a neutral from any part of that circuit.

Do not 'borrow' a neutral from one circuit to add to a different circuit.

 

[mwatsonxx]

Do you have RCDs in your consumer unit? Are the lighting circuits on different RCDs? If yes to both, then they are the same neutral.

No they would not be on the same neutral. Look up RCD's and how they work.

If not, it should be but impossible to be 100% without testing it. sometimes the landing light if it has 2 way switching is on the downstairs live and upstairs neutral, but that wouldn't cause you an issue.

Borrowed neutrals are an electrical shock and fire hazard and have caused many associated injuries and deaths.

 

[mwatsonxx]

If you really only have one true lighting circuit, then you can obtain a neutral from any part of that circuit.

Do not 'borrow' a neutral from one circuit to add to a different circuit.

To the op, take sparkwrights advice he is correct

 

[JohnW2]

No they would not be on the same neutral. Look up RCD's and how they work.

Just to offer a guess, to give you something to moan about, I suspect that it was a typo.

Borrowed neutrals are an electrical shock and fire hazard and have caused many associated injuries and deaths.

I don't understand that at all. Could you perhaps clarify?

Kind Regards, John

 

[JohnW2]

Do not 'borrow' a neutral from one circuit to add to a different circuit.

I can't see how it can be on a different circuit/RCD if, as we have been told (twice), the proposed source of the neutral shares the same MCB.

Kind Regards, John

 

[sparkwright]

I can't see how it can be on a different circuit/RCD if, as we have been told (twice), the proposed source of the neutral shares the same MCB.

Kind Regards, John

I'm just generalising.

The circuit in question appears to be fine.

I'm just backing that up by stating that wouldn't add a neutral from another circuit. Sorry to have caused confusion, was giving the op some simple background info.

 

[mwatsonxx]

Just to offer a guess, to give you something to moan about, I suspect that it was a typo.

I have never commented on a typo by anyone. The meaning of the whole sentence is wrong, that is not a typo, that is incompetant advice.

I don't understand that at all. Could you perhaps clarify?

I'll give you one bit of advice, improve your teaching of electrical knowledge and don't get so uppity when your protoge is criticised for being wrong.

 

[333rocky333]

It was no typo, Johnd2 was right, If all the relevant lights , passage and 1st floor are on that 1 mcb and its on 1 rcd and the other non relevant ground lights are on a mcb on another rcd, then that would confirm that there is NO borrowed neutral to the relevant passage and 1st floor lights and that the passage and the first floor lights do use the SAME neutral.
If they were on the same rcd or have no rcd, then there could well be a borrowed neutral

 

[John D v2.0]

then does the mean they all share a same neutral wire?

If yes to both, then they are the same neutral.

Sorry, just for clarity I was meaning these "they" being the same thing, not any reference in the post I made!
Thanks for the polite corrections

 

[John D v2.0]

Borrowed neutrals are an electrical shock and fire hazard and have caused many associated injuries and deaths.

I don't understand that at all. Could you perhaps clarify?

I'll give you one bit of advice, improve your teaching of electrical knowledge and don't get so uppity when your protoge is criticised for being wrong.

Great clarification...

I've learnt more from him than from anyone else on here, clearly not much chance of learning anything from you.

I presume all the fires caused by borrow neutrals were by borrowing lighting neutrals for cooker circuits, and all the electrocutions were caused by incorrect safe isolation procedures.

 

[333rocky333]

I can't see how it can be on a different circuit/RCD if, as we have been told (twice), the proposed source of the neutral shares the same MCB.

Kind Regards, John

Isnt that what a borrowed neutral is though, with NO rcds in the mix, the live source mcb would still do both 1st floor and passage light, but the neutral could still be bunched to the other ground floor circuit, the problem arises when working on that ground floor circuits neutral.