electrical help needed

mattmo

mattmo

Suspended / Banned
Messages
326
Edit My Images
No
hello all

I am just about to put a new light up and have notice i have 2 live wires and 2 neutral wires coming out of my ceiling, i have connected everything up but have one live and one neutral left not connected and the light doesnt switch off!

any ideas?:shrug:

cheers

matt
 
Okay, it sounds as though you have connected the supply from the fuse board to the live of the light and the nuetral from the fuseboard directly to the light fitting completely excluding the switch.
I'm assuming (thats all i can do without seeing with my own eyes and a tester) that there would be no voltage on the remaining wires(DONT TEST THIS WITH ANY BODY PART!
), as one is going to the light switch and the other is the switch wire.
Do all the other lights in the house work as normal?

Don't assume that a black wire is always a neutral, it could be the switched wire, meaning you could have full 230vac on it.
If it is a switch wite it should have red tape round it, but this is rarely the case.
 
Hey Matt - I agree with what Si said above, you'd best get an electrician if you are not comfortable with this. You could do yourself a serious injury, honestly.

However - as a fyi of course and NOT suggesting you do this yourself...

You state there are two live and two neutral wires coming out of the ceiling yes...? Are you stating this because two are brown or red, and two are black...?

Let's examine this scenario: A single light being illuminated by a single switch.
The live (brown or red) from the supply comes into the switch, and a single 'switched live' (could be red or brown - or anything the person who installed it used really - this is the danger) goes to the ceiling rose and on to the bulb. The other side of the bulb (usually black) then returns to the neutral side - so when the switch is switched, power gets through to the bulb and it illuminates.

When there's more than one wire coming to/from a ceiling rose, it means there's either another bulb in the circuit (as in the case of hallway/landing combination), or perhaps a feed has been taken from that ceiling rose to feed another light switch elsewhere in the lighting circuit.

If this were set up according to building and electrical regs, then the supply (common live) should be taken to the ceiling rose, then to the switch, then back to the switched live of the ceiling rose, out to the bulb, back from the bulb to the common neutral.

Hope that explains (1) what might be happening and (2) how dangerous it can be when messing with electrical supply... it's a killer if errors are made.
 
thanks for the quick replies, all my othe lights work as normal and there was no other tape around the wires.

matt
 
To be honest Matt, we can only guess at what each wire is for.
I know how the circuits are supposed to be, but that doesn't mean that they are actually wired correctly.

I really think you should contact an electrician.

IF you do decide to do this yourself, please remember to trun the power off at the fuseboard and check each wire with an electrical voltage meter to ensure there is no voltage present.

Also please note that a neutral wire could possibly be carrying the full supply voltage.

It takes half an amp to kill, there is around 6 amps in your lighting circuit!
 
Are you replacing an existing light? If so - how was it wired?

In my new build I had this a lot - typically the cables were together on the original light, but as I took it out they seperated due to the thickness.

Just checked and mine are together now (ie 2 live, 2 neutral) into the light...

AS others have said - if in doubt, get someone in :)
 
Just checked and mine are together now (ie 2 live, 2 neutral) into the light...


Do you mean you have the two live into one part of the light fitting and the two neutral into the other part?
 
A very basic lighting circuit.
basic-lighting.jpg


As you can see in this diagram i prepared earlier :D the black wire from the switch is just an extension of the live wire!
 
mattmo said:
Just checked and mine are together now (ie 2 live, 2 neutral) into the light...


Do you mean you have the two live into one part of the light fitting and the two neutral into the other part?
Click to expand...

No, this could cause a short.
 
I get phone calls from family asking "right i took the light fitting down from in the kitchen and......there is about 9 wires, where do they all go?" :|
 
mattmo said:
Just checked and mine are together now (ie 2 live, 2 neutral) into the light...


Do you mean you have the two live into one part of the light fitting and the two neutral into the other part?
Click to expand...

That's what's on mine, but it depends on what dependencies // wiring configuration is installed in your rooms etc
 
Thanks for all your replies, I think the best course of action is ring an electrician.

Thanks again

matt
 
mattmo said:
Thanks for all your replies, I think the best course of action is ring an electrician.

Thanks again

matt
Click to expand...

Good plan. Offer the sparky a portrait in return for sorting your light :D
 
It always amazes me that folk are nervous of plumbing, but will launch into electrics with the minimum of knowledge.

How many plumbers drown ? Not many. Folk are always more afraid of making a mess than killing themselves :shrug:.

If you had picked another light fitting you could easily have had nine sets of wires and after you have disconnected the light you would need a meter to identify them all.

Get an electrician, smile and pay-up.:D
 
You must log in or register to reply here.
Back
Top