Ceiling light which wires??

[nanbullen]

Forgot to take a photo on removal of old light... Please can you tell me which wires to into the terminal block? I only have only one live wire which I've marked with Tippex. The earth wires were already in a separate terminal block. Please use simple language and just colours. Thanks for any help.

 

[ETAF]

do you have a meter to test
you probably have
RED/Black from 1 cable = LIVE in
RED/Black from 2nd cable = LIVE out to other lights
RED / Black from third cable , will be a Live to the switch - RED, and a live back from the switch Black, 3rd cable - so need to work which cable set that may be

so of those 3 black 2 MAY be neutral and one LIVE -

and wont just work with that connector block , needs 4 connectors
Live common - 3 cables in a connection
Neutral common - 3 cables in a connecton - 2 from ceiling and 1 to light
Live switched - 2 cables - 1 form the celing & 1 to light
Earth - maybe 4 connections - 3 from ceiling and 1 to light

 

[nanbullen]

I checked with a meter. The only live wire was the one I tippexed.

 

[ETAF]

so thats the live in - you need now to work out which black and red goes to the switch

 

[mikeyd]

If you set your meter to continuity (where it beeps when you touch the probes together) you can identify which cable goes to the switch. One of the red/black pairs will cause the meter to beep when the switch is on. It won't be the cable you have identified as having the red live (feed in) but you need to work out which of the other 2 cables it is.
The remaining cable will then be a feed out to another room / different set of lights. Or does the switch control more than one light?
Anyway, once you have identified the switch cable we can explain how to connect your light. Any attempt without working out the switch cable will result in fuses blowing or breakers tripping (at best).

BTW, I have used the term cable as meaning a bunch of wires contained together. You have 3 cables, each with 3 wires (red, black and bare CPC(earth))

 

[nanbullen]

So, I try each of the black wires with the live wire to see which combination beeps?

 

[pete01]

Turn the power OFF

Seperate the reds and blacks into sets, test between each set, one set will beep on and off as the switch is switched on and off.

 

[nanbullen]

Or, do you mean I should just try the other 2 red wires with each of the black to see if they beep?

 

[Taylortwocities]

Or, do you mean I should just try the other 2 red wires with each of the black to see if they beep?

No. The switch cable will be a red and black. You only need to look for the red and black in the same cable that goes on and off when the switch is activated.

 

[mikeyd]

Can you not identify which pairs of black/red are together in a cable? Your photo does show they are up in the ceiling.

 

[blup]

Turn the power off and pull the cables through and upload a pic

 

[FrodoOne]

I checked with a meter. The only live wire was the one I tippexed.

How did you determine that that Red wire was the Line wire.
Did you check between Earth and each of the Red wires?

If so, after you identified the incoming Line wire,
you could have tested between it and each of the Black wires,
to determine which of these was the incoming Neutral.


You will need other connectors and you may be better off using a standard UK Ceiling Rose'
See https://flameport.com/electric/lighting_circuits/lighting_ceiling_rose_other_colours.cs4
for the connections required - as illustrated in the two right-hand diagrams.

Note the need to designate/label the Black "Switching" wire as a "Line" wire, using Red sleeving - or similar.

 

[nanbullen]

Thanks for your replies, all. It's too complicated for me. I'm going to call an electrician out.

 

[FrodoOne]

Thanks for your replies, all. It's too complicated for me. I'm going to call an electrician out.

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