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.

 

[Tony Good]

Thanks for that Leesparkykent - I totally understand you skilled guys telling me to step away from the wiring. Was just trying to help out a friend with no money to get a spark in. Big mistake.

 

[sparksburnout]

Thanks for that Leesparkykent - I totally understand you skilled guys telling me to step away from the wiring. Was just trying to help out a friend with no money to get a spark in. Big mistake.

What would you have done if you could smell gas? Back to Muddy Waters again...

 

[Darkwood]

Careful don't do anything dramatic..... And can I just ask, this guys a MEMBER??? Why is he a member?

If your refering to the term EF Member under the avatar then that applies to anyone registered in the forum and is just the general basic status, staff need to assign other titles and unless we are made aware as we cannot follow every post in every thread then we sometimes rely on our regulars to report and suggest the member be better with other assigned status like DIY.

Has his introduction to the forum in his other thread clearly states he is an Electrical enthusiast with no formal qualifications then we will update his status.
Please help us if you see similar situe's by letting us know with the report button as oppose to making a brash response in the thread which helps no-one.

 

[sparksburnout]

Thanks for that Leesparkykent - I totally understand you skilled guys telling me to step away from the wiring. Was just trying to help out a friend with no money to get a spark in. Big mistake.

Is it me or was there just a touch of sarcasm in there??

 

[sparksburnout]

If your refering to the term EF Member under the avatar then that applies to anyone registered in the forum and is just the general basic status, staff need to assign other titles and unless we are made aware as we cannot follow every post in every thread then we sometimes rely on our regulars to report and suggest the member be better with other assigned status like DIY.

Has his introduction to the forum in his other thread clearly states he is an Electrical enthusiast with no formal qualifications then we will update his status.
Please help us if you see similar situe's by letting us know with the report button as oppose to making a brash response in the thread which helps no-one.

Bring back DS thats what I say, think about it.

 

[The Ghost]

Well that is a good point. This is what people do when they do not have the money to afford a tradesman, have a go. Its just unfortunate to be in such a position. Maybe post a piccy tomorrow. But please make sure the electrics is defo off! The legal position is very fraught for you if something goes wrong. Its a lesson to us all, stick to what you know and have been trained for.

 

[buzzlightyear]

I have just looked at the picture on the light fitting was the screws on the copper conductor or the pvc. sheath ?

 

[Pat H]

If you only altered the wiring in that ceiling rose then yes you have interrupted the normal L/N feed that loops from one fitting to the next. All the lights normally have live and neutral and earth fed to them from the consumer unit. Most ceiling fitting have a bus bar at one end connected to the neutral of the light flex this bus bar has the incoming Neutral and outgoing neutral (unless its the last light in the chain)
The bus bar on the other end connects to the live light flex via the switched live feed.
The center bus bar has the incoming live and outgoing live (unless its the last light in the chain) and then it also has the live feed to the switch. The complication is the cable used to go the switch is normally a twin and earth so has a live neutral and earth wire and it actually switches live so we have to indicate that the neutral is actually carrying live and we do that by putting a sleeve on each end to match the live colour.
But often that sleeve isn't present so its easy to get wires mixed up.
What's needed is to identify the incoming feed the outgoing feed and the switch wire.
Easy if you know what's what but dangerous if you don't.
Its not a big job for an electrician and I'd advise you get some help to be sure its correct and safe.

 

[The Ghost]

re the above I mean above Pat H and Buzzlightyear

help out a friend with no money

 

[buzzlightyear]

try salvation army.

 

[Tony Good]

I've made sure the current is off before going near anything and may well post a picture of the wall switch tomorrow. Looking at some typical lighting circuit diagrams I can see how it should be wired up but can't find anything that shows the way the switch is currently wired and can only suppose it is wrong. Will find an electrician tomorrow who can hopefully help. Thanks anyway guys.

 

[Tony Good]

If you only altered the wiring in that ceiling rose then yes you have interrupted the normal L/N feed that loops from one fitting to the next. All the lights normally have live and neutral and earth fed to them from the consumer unit. Most ceiling fitting have a bus bar at one end connected to the neutral of the light flex this bus bar has the incoming Neutral and outgoing neutral (unless its the last light in the chain)
The bus bar on the other end connects to the live light flex via the switched live feed.
The center bus bar has the incoming live and outgoing live (unless its the last light in the chain) and then it also has the live feed to the switch. The complication is the cable used to go the switch is normally a twin and earth so has a live neutral and earth wire and it actually switches live so we have to indicate that the neutral is actually carrying live and we do that by putting a sleeve on each end to match the live colour.
But often that sleeve isn't present so its easy to get wires mixed up.
What's needed is to identify the incoming feed the outgoing feed and the switch wire.
Easy if you know what's what but dangerous if you don't.
Its not a big job for an electrician and I'd advise you get some help to be sure its correct and safe.

Very helpful post, thank you. Two of the wires behind the switch do have sleeves on but the ones in the ceiling do not.

 

[Pat H]

Is the switch with the sleeved wires one of a pair? Is there a matching switch somewhere?

 

[buzzlightyear]

frank spencer comes to mind !

 

[Tony Good]

Pat, tricky to describe but there basically two switches on the plate. The twin and earths that come from each ceiling light to the back of the switch are interconnected between the switches, which just seems wrong.