Home electrics...what have I done?

Looking for some help/advice. I know very little about electrics.

I changed a light fitting earlier in a room which works fine. But the one in the adjacent room has now stopped working. It's a multi bulb affair, on the same circuit as the other light and hasn't been touched so it seems like I've killed the power to it somehow.

When I changed the fitting I did touch, there were 3 live (red) wires joined together in a block that was not connected to anything else.
I joined these back together. It's possible that this has come apart perhaps.

There was a further live cable that was connected to the original fitting, which is the one I used for my new fitting.

There were 2 black negative wires that were joined together and used in the original fitting, that again I replicated in the new fitting.

Then there are 3 earth cables that were joined into the old fitting, but the new fitting does not use an earth so I joined these together in a sleeve and left them unconnected to anything else.

So....what's gone wrong? And how do I fix it?

Re:

First, check all your connection are as should be and take some pictures.

Did you check the wires, or just assume the colour coding was correct?
First socket I opened up in this house had 5 black and 2 green wires, some connected to each other.

I went and got a circuit tester.
Just did some electrical work before Christmas, 9 wires in 4 colours. The only one that was correct was one of the earths.

Re:

I assumed, but it's a fairly new house so should be ok.

Plus the fittings worked before with that set up... Or close. Been mulling it over and I think what I've done is disconnecte the second fitting from the lighting circuit. I presume one of the additional live feeds is supposed to carry the power to the next light on the circuit.

Assuming your in the UK.
Remember that the lightfitting and switches will be still live when the lightswitch is turned off.
Each lightfitting is connected in series, the Neutral on the bulb holder is permanently connected to the Neutral on the circuit. The Line (live) is connected to a separate connector and the lightswitch wires (ideally both will be brown or brown sleeved) connect between the Line of the circuit and the Line of the bulb holder.
All earths should be connected together, if the lightfitting has no touchable metal parts then they don't have to connect to the lightfitting, just to each other but it must be secure.

Just remembered you have the old colour wiring. So:
Brown = Red
Blue = Black

And make sure you isolate everything and test, some people share between upstairs and downstairs lightcircuits so test everything before touching.

mattr":khjymbuv said:

Did you check the wires, or just assume the colour coding was correct?
First socket I opened up in this house had 5 black and 2 green wires, some connected to each other.

I went and got a circuit tester.
Just did some electrical work before Christmas, 9 wires in 4 colours. The only one that was correct was one of the earths.

Click to expand...

Green that's an old Earth colour before it went green/yellow.

Yellow is used now, but found as 4 wire setups often used for dual switch setups but you'll see colour tags to shows some other colours are actually live.


I'm sure these is something in the new regulations where only competent people should be doing DIY else rendering it illegal to do if you're like the Poster, not competent at doing it.
So from a legal perspective for the site (assuming it has any legal duty) you should get somebody in that knows what they are doing).

Changing basic things such as bulb holders, sockets and switches are not required to be notified assuming they are not in a location containing a shower, bath, swimming pool, sauna or gimp dungeon.

Although the person should be competent.

As the OP says, something is no longer connected, either on the the three red wires (circuit in and out and switch feed) or one of the blacks (circuit in and out).

FluffyChichen":2lwaz3qs said:

Green that's an old Earth colour before it went green/yellow.

Yellow is used now, but found as 4 wire setups often used for dual switch setups but you'll see colour tags to shows some other colours are actually live.


I'm sure these is something in the new regulations where only competent people should be doing DIY else rendering it illegal to do if you're like the Poster, not competent at doing it.

Click to expand...

I am "competent", that's why the house is still standing and all the electrics still work.

The guy who wired (and plumbed) the place needs stringing up.
Most of the downstairs is green and black, the colour coding means nothing, i have live greens, live blacks and Blue earths.

I take notes, and use a circuit tester.

The diagonal runs across ceilings and walls are interesting.

Re:

Yep, I think they were talking about me being the incompetent one!

It's one of those things, sometimes you open the sucker up and it's straightforward replication of what is already there. I did a bathroom fitting on the same day in about 5 minutes. This one is a little more complicated. I wouldn't do anything nuts, and if I can't solve it easily would call an electrician.

Re:

There is not much end point domestic wiring that is complicated, and a visit to one of the many dedicated DIY home electrics sites and a methodical approach should enable you to do most of what is required. Generally speaking if wiring a new extension or refitting your kitchen/bathroom/workshop, any major work, you ought to get a spark in to sign it off. Worth getting a spark in for a look over when you discover 'interesting' wiring, could be a bodger has been at work, and you really don't want to find that out the hard way.