Confused about a light in a bathroom...

jarvisob

So two cable coming into light fitting with red and black used for live and neutral.... when testing with the multi-meter then cable 1 has 230V across the live and neutral regardless of switch position...

Cable 2 has no voltage across it regardless of switch position.

I'm an electrician but trying to solves this problem for my brother over video-skype as he's in London. It's confusing me.... the switch should be affecting the power to one of the cables yes? By my reckoning if it's connected up as is then the light will be constantly on but he says the switch worked that fitting before ( with the old fitting).....any advice appreciated.

TheBadBadger

jarvisob wrote: »

So two cable coming into light fitting with red and black used for live and neutral.... when testing with the multi-meter then cable 1 has 230V across the live and neutral regardless of switch position...

Cable 2 has no voltage across it regardless of switch position.

I'm an electrician but trying to solves this problem for my brother over video-skype as he's in London. It's confusing me.... the switch should be affecting the power to one of the cables yes? By my reckoning if it's connected up as is then the light will be constantly on but he says the switch worked that fitting before ( with the old fitting).....any advice appreciated.

Sounds strange!!!!

What type of fitting was installed before, maybe it required a permanent supply?

jarvisob

will get the photos uploaded soon.... just some more info in meantime. The two cables have two red, two blacks and two earths but one of the black cables has red insulations tape around it? so now 3 reds, one black.

I got him to buy a multi-meter and send me on pictures.... so last night then using video-skype tested the wires...cable one constantly has 230v and cable two is constantly off regardless of the switch position...tested cable one off earth and the red is live and the black is neutral. So cable 2 is the one with the red tape around it's black wire....

No wires have been changed anywhere...says that switch controlled the last fitting fine. Their was a connector used inside the last fitting but not sure how this was wired up...

maxfresh

Could it be wired in the three plate ceiling rose method, where the perm live and neutral is brought to the light and then another twin cable down to the switch

TheBadBadger

jarvisob wrote: »

will get the photos uploaded soon.... just some more info in meantime. The two cables have two red, two blacks and two earths but one of the black cables has red insulations tape around it? so now 3 reds, one black.

I got him to buy a multi-meter and send me on pictures.... so last night then using video-skype tested the wires...cable one constantly has 230v and cable two is constantly off regardless of the switch position...tested cable one off earth and the red is live and the black is neutral. So cable 2 is the one with the red tape around it's black wire....

No wires have been changed anywhere...says that switch controlled the last fitting fine. Their was a connector used inside the last fitting but not sure how this was wired up...

Maxfresh is spot on there.. The supply is simply brought to the light fitting via your twin and earth reading 230..

It was more than likely then connected as follows :

Feed in (red230V) connected to either other red

now you are left with your neutral (only black) and switch wire, remaining red..

I say it doesn't matter which red connects to the supply on an assumption it is a 1 gang 1 way switch.

You are a sparks so suffice is to say, isolate this circuit before any connections are made

jarvisob

Thanks gentlemen......all sounds simple now! Just was confused earlier..hard when not actually there and hadn't seen how earlier fitting was connected....very much appreciated!!!!!! Will conclude safely over another video skype tomorrow...:)

Dg_

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