Two way lighting circuit gone wrong

[Tony Good]

I'm hoping to get a bit of expert advice on a problem I have with a friend's wiring. Initially I was asked to take a look at a three-bulb light fitting that was regularly blowing bulbs. I took the fitting down from the ceiling to check for loose wires and found that several came out from the connectors on gentle manipulation.

I re-prepared the free wire ends (they looked a bit damaged) and inserted them back to where it looked like they came from, disconnected the fitting and checked and cleaned the bulb sockets, looked like some arcing was going on arond the bulb thread.

What's most bizarre on reconnection of the fitting though is when the light is OFF the bulbs glow dimly and when it's switched ON they glow normally. It's part of a two ceiling fitting and two way switch circuit with ordinary 40w filament bulbs.

Looking at the back of the wall switch it looks like the two circuits are crossed between the switches - I just can't understand why it was wired like this and wondered if it sounds like a familiar, albeit odd, setup to anybody?

Would welcome any sensible input _thanks all.

 

[rolyberkin]

I normally hate the kind of reply I am about to give you, but in this case I will make an exception. Without sounding condescending if you need to ask how to rectify this then you shouldn't be doing it, get someone in to take a look.

 

[egg67]

Take a picture of light wireing and post it, it would be very helpful to help you

 

[Nickj]

Do you have a photo of the wiring to the switch?

 

[Tony Good]

I normally hate the kind of reply I am about to give you, but in this case I will make an exception. Without sounding condescending if you need to ask how to rectify this then you shouldn't be doing it, get someone in to take a look.

Hi Rolyberkin - believe me I wish I hadn't got invloved! I understand basic electrics and electronics but this is just baffling as to why the bulbs would glow dimly when turned off the normal when on. I'd really appreciate some pointers.

 

[Tony Good]

I normally hate the kind of reply I am about to give you, but in this case I will make an exception. Without sounding condescending if you need to ask how to rectify this then you shouldn't be doing it, get someone in to take a look.

Working on it..

 

[sparksburnout]

I normally hate the kind of reply I am about to give you, but in this case I will make an exception. Without sounding condescending if you need to ask how to rectify this then you shouldn't be doing it, get someone in to take a look.

Oh I say.................spot on sir.

 

[HandySparks]

See my reply to your other thread. Why did you start two???????

 

[buzzlightyear]

best way, get some tape .cut the cable. tape the end on ceiling put the fitting back up
take the the bulbs out by some candles and fit them in stead.

 

[rolyberkin]

Hi Rolyberkin - believe me I wish I hadn't got invloved! I understand basic electrics and electronics but this is just baffling as to why the bulbs would glow dimly when turned off the normal when on. I'd really appreciate some pointers.

Sounds like you have put the cables back into the wrong connectors on the ceiling rose, how many cables going into the ceiling rose/light? As others have suggested a photo would help.
The cross wire in the switch will be a live being fed from one gang of the switch to the other, do you have test equipment? These are a bit of a pain unless you are there looking at it and have test equipment to see what cable is going where, hence my previous comment.

 

[snowhead]

I understand basic electrics and electronics but this is just baffling as to why the bulbs would glow dimly when turned off the normal when on. I'd really appreciate some pointers.

If you understand Series and Parallel, you've created series where it was Parallel.

 

[Tony Good]

See my reply to your other thread. Why did you start two???????

Sounds like you have put the cables back into the wrong connectors on the ceiling rose, how many cables going into the ceiling rose/light? As others have suggested a photo would help.
The cross wire in the switch will be a live being fed from one gang of the switch to the other, do you have test equipment? These are a bit of a pain unless you are there looking at it and have test equipment to see what cable is going where, hence my previous comment.

Thanks rolyberkin, I have a Fluke meter and have uploaded a couple of photos of the wiring - god knows where they have ended up on the forum though. I've ascertained which wires go to the switch, there are three twin and earth cables going to the fitting, all lives are connected together, two neutrals seem go together into the light fitting neutral and the switch wire returning feeds the live.

 

[Richard Burns]

Lights glowing when they are off, as has just been said by Snowhead!, indicates that the light is getting a supply from the neutral of another light so both lights in series gives a dim glow as they are at half voltage.

 

[Tony Good]

If you understand Series and Parallel, you've created series where it was Parallel.

Thank you snowhead, that's a good clue

 

[buzzlightyear]

is it loop in to centre light.mr good how many rocker switches in the room

 

[Tony Good]

Hi thanks for reply, I've attached two photos of each fittings wiring (one untouched original) there are two rocker switches in the room.

 

[westward10]

If you understand Series and Parallel, you've created series where it was Parallel.

Was thinking exactly the same.

 

[Tony Good]

The first picture is the non working fitting and the wire with the blue tape is the one going to the switch, I isolated it and circuit tested each wire so I'm sure that's correct. Seems to be the other wires that have caused the problem but if I try to wire it any other way the breaker for the downstairs lights trips out.

 

[Tony Good]

The first picture is the non working fitting and the wire with the blue tape is the one going to the switch, I isolated it and circuit tested each wire so I'm sure that's correct. Seems to be the other wires that have caused the problem but if I try to wire it any other way the breaker for the downstairs lights trips out.

 

[The Ghost]

Just a thought but looks like your neutral in the first picture is not properly connected thus you will have a live neutral. Try connecting them properly into the terminal block with no copper showing and see what happens. A picture of inside the light switch would also help. When you say two way light switching do you mean one switch controls one light and the other switch the other light or two way light switching meaning there is another switch at another location which also switches the both lights on at either position? That "cross" at the light switch you mention might just be a linked live to supply the other light via the other switch.