4 Core cable question

[johnrg]

It should be simple... but i think i am!

I'm in a new build property, built in 2007, and I'm trying to fit an external light from the cable that was installed when i moved in.

The cable is 4 core. A grey, black, brown and a plain copper wire.

The light has a Neutral, Earth and Live connection.

What goes where?

Cheers,

John

 

[pompeygit]

some questions:
Did you take down an existing light?
Are any of the cores marked wth coloured tapes or sleeving?
Have you opened up the light switch that serves this light and made a note of how it is connected?
If you find out this info I am sure you will get help

 

[breezer]

Did you take down an existing light?

I'm in a new build property, built in 2007, and I'm trying to fit an external light from the cable that was installed when i moved in.

What goes where?

no idea, depends how who wired it, wired it.

Get a multi meter and find out which core does what.

The bare one should have green /yellow sleaving and connected to earth

 

[johnrg]

Ok...

Glad you suggested opening the switch, its not conencted! lol That would have been and anti climax.

There are 3 cables going into the switch. of the 3, 2 have their brown wires connected to the common on the switch, and their blue wires connected together

The copper wires are all connected together with green/yellow cover and are attached to the switch cover.

On the external cable, the brown and black (which has a brown sleeve on) are connectred, and the grey wire has a blue sleeve on.

Does that help you? I really should have paid more attention in the electronics modules of my degree...

Cheers,

 

[GaryMo]

On the external cable, the brown and black (which has a brown sleeve on) are connectred, and the grey wire has a blue sleeve on.

So the grey conductor with blue sleeving (neutral) is connected to the other two blue conductors? Are these in a connector block?

Where exactly are the brown and black connected? Is the brown connected with the other two browns in the common terminal and the black (sleeved brown) in a terminal on its own, possibly L1?

 

[johnrg]

The two 2 from the mains wires are connected in a connected block, but the thrid blue isn't connected to anything. So the connector block is only connected from one side.

And the brown and black are taped together not conencted to anything.
nothing is connected to the L1 on the switch.

 

[GaryMo]

So, the light fitting you have is a standard switched fitting and doesn't have motion detection or a dusk/dawn sensor?
I assume so by you saying there's only three terminals - L, N and Earth.

Isolate supply and check!

Connect the brown of the outgoing cable to the L1 terminal on the switch, the other side (fitting) is connected to the L terminal.
Connect the grey conductor (sleeved blue) to the other two blues in the switch and the fitting end to the N terminal.
Take the brown sleeving off the black conductor and place green/yellow sleeving on both ends, also place green/yellow sleeving on both ends of the bare copper conductor. Terminate both the black conductor (now sleeved g/y) along with the bare copper conductor (also sleeved g/y) with the other CPC's (earths) at the switch. At the fitting end both will terminate into the E (earth) terminal.

Switch - Conductor - Fitting

L1 - Brown - L
N - grey(blue) - N
E - black(g/y) - E
E - bare(g/y) - E

 

[johnrg]

Thanks Gary,

All working great!

Much appreciated. Have a great week.

John

 

[GaryMo]

Glad to hear John

I'm sure I'll have a very good week as I'm off to Turkey for a fortnight on Thursday