Missing neutral...

Mike Blair · Jun 2, 2015

got a call and they said they had a 2 way switch and it stopped working.. after they changed some lights and sockets. The switches them selfs where both trying to switch one light i looked inside and seen the neutral in earth sleeving... but No actual earth was connected "metal faced socket after some tests found out one cable coming in is a switch wire for the first light and the other cable coming from the second cable is live and neutral...

all fixed and corrected now but can someone explain to me...How the hell did they have it working in the first place??

uksparks · Jun 2, 2015

You have three conductors there that could be connected, two browns and a blue, I am sure this would have worked fine.

The neutral is possibly sleeved in green and yellow as its a conductor that is not being used and they have done the sensible thing and earth it which is why you are supposed to do and not just chop it off. I can see an earth there too.

The front faceplate if metal should have a tag to join on to, which you should, but if its screwed into the back box, it will make continuity anyway, so not as bad as it sounds.

Mike Blair · Jun 2, 2015

sorry for the bodgy diagram but this is what it was wired like

uksparks · Jun 2, 2015

Just a thought, but I'd be inclined to think a jumper has been removed.

uksparks · Jun 2, 2015

My thinking is that you have a brown and blue coming in the back, the brown is permanent live and the blue is the switched live going back to a fitting, and the other brown wire, I would suspect this is just a switched live that would be connected to L1 or L2 on one of the switches, and a jumper from the other brown which should be in COM to the COM on that switch maybe.

Don't forget to sleeve the blue with some brown.

Mike Blair · Jun 2, 2015

the neutral in the switch isn't to the supply that's the return neutral so them 2 lights need a return path you get me?

uksparks · Jun 2, 2015

Have you actually put a meter between any of them to see which you have voltage on?

Mike Blair · Jun 2, 2015

yes i found out what was a switch wire and what was not. this diagram make more sense on what i had?

uksparks · Jun 2, 2015

If you say it's like it is, there's no way it could work as you don't have a permanent live at the switch.

Mike Blair · Jun 2, 2015

that's what i said when i went in. one light "the one light on its own" was switching and the other 2 did not turn on. but thay said before the builders came in and did the work. the lights worked on a two way switch but i really cant see how it worked? heads baffled

uksparks · Jun 2, 2015

I think I'd need to be there to see it to be able to say what's wrong.

Mike Blair · Jun 2, 2015

another image

uksparks · Jun 2, 2015

I'd try connect the two Browns to the other side of the switch, so you have the blue in L1 on one side, and the jumper between the commons, and a brown in one of the con I s with the jumper and the other brown in L1 on the other switch, you may have to swap the Browns if it doesn't work one way, try them the other way, what you need is the permanent live in the common with the jumper.

egg67 · Jun 2, 2015

Think he fixed it, just wants to know why it was working before builders changed the fitting with that wiring, but unless we can see the wiring before the builder f:cked it up we will never know
But at lest Mike fixed it and left it nice and safe

Mike Blair · Jun 2, 2015

i fixed it not the best method...but its safe and works and didn't kill the client with a bill

I feel bad when it happens to people. they pay alot of money for something and no one tests the lecky..so once all the floors in and tiles are on....then there's a problem and it all has to come off due to a idiot