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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Three Core and Earth into Two Core and Earth? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1298733482 Message started by Lukas on Feb 26^th, 2011, 3:18pm

Title: Three Core and Earth into Two Core and Earth?
Post by Lukas on Feb 26^th, 2011, 3:18pm

Hi

I ripped out some old strip lights and I am replacing them with spot lights. The cable coming out of the wall is three core and earth (black, brown, grey, earth) but the spot lights are intended for two core and earth. Is there an easy way to fix? Any help much appreciated!

Title: Re: Three Core and Earth into Two Core and Earth?
Post by CWatters on Feb 26^th, 2011, 7:06pm

How were the old spots wired?

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lukas on Feb 27^th, 2011, 8:10am

Hi

The lights that I took down were fluorescent striplights connected in series. The picture shows the how the first one was wired to the mains.

[gallery]LukasK/1298794026.jpg[/gallery]

Title: Re: Three Core and Earth into Two Core and Earth?
Post by CWatters on Feb 27^th, 2011, 10:31am

Looks like you have a dimmer switch?

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lukas on Feb 27^th, 2011, 10:52am

There is no dimmer switch

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lectrician on Feb 27^th, 2011, 2:02pm

Photo of the switch? Including inside it?

It does look like a dimmable fluorescent - relatively rare. It has been connnected up as if there is a dimmer, and was wired with three core for that reason.

We need to see the switch to be able to advise how to wire it.

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lukas on Feb 27^th, 2011, 5:49pm

Not sure this makes it any clearer - lots of shadow, but basically two black, one brown wire (all other cables isolated).

There could well have been a dimmer on there once, but if so it's been replaced. We have dimmable fluorescents in another room.

[gallery]LukasK/1298828420.jpg[/gallery]

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lectrician on Feb 27^th, 2011, 10:03pm

Are you UK based? This wiring suggests not?

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lukas on Mar 1^st, 2011, 5:04am

No - I'm an expat based in Norway. I have decided to remove the 3c+e cable and pull a 2c+e cable through instead, since it looks fairly straightforward.

Title: Re: Three Core and Earth into Two Core and Earth?
Post by CWatters on Mar 1^st, 2011, 12:17pm

I wouldn't do that unless very easy to pull through. I'd Just leave one core disconnected both ends. Put the unused ends into a terminal block and insulate.

Norwegian wire colour codes here ..

http://en.wikipedia.org/wiki/Three-phase_electric_power

suggest if you decide to use the existing wire you use..

Live = Brown
Neutral = Sleeve the Grey wire both ends with Blue sleeve
Earth = green/yellow wire (or sleeve).
Black wire unused.

Obviously need to comply any local regulations.

Title: Re: Three Core and Earth into Two Core and Earth?
Post by Lukas on Mar 12^th, 2011, 5:52pm

Thanks - i ended up plugging the lights into a nearby socket as a temporary solution (while i finished tiling the bathroom). I have just wired in the lights as per your advice and everything works perfectly. Many thanks for your help!