two gang switch problems

[Gerbil4Ben]

After fitting new wall lights in my brothers flat they do not work.
It has been some time since the circuits were last in use but I checked them before we started and there was power going to them. As a matter of safety I always turn off all power to his flat (via the main breaker) as we have had problems before (I think the previous guy just bunged cable and stuff where he liked). On finishing the initial installation on the the new wall lights we turned on the power and the was a small bang, which we tracked down to one of the live cables becoming trapped by the housing on the new light fitting and connecting to ground. After having redone the connection and rerouting the cable behind the light fixture and turning the power back on there is now no power at all in the circuit, in the two fixtures or the switch.
To make it more complicated the guy who installed the wall lights in the first place has a two gang switch on the wall on which on switch is fed by the lighting circuit and controls the ceiling light and the other switch is powered by a spur off the mains ring and should control the wall lights. All the breakers are on but this spur has no power going to it.
Can anyone think of a reason that a functioning circuit that has had to have a breaker reset on it should now not work at all?

 

[mikeyd]

Welcome.

You must get rid of that spur. You should not have more than one circuit in the same switch and your wall lights and the wiring to them are not meant to be on a ring final circuit as they are probably not rated for it. Was is a 32A breaker you had to reset?

 

[Gerbil4Ben]

Thank you

The Breaker was a 16Amp and is now running the rest of the circuit fine.

 

[mikeyd]

I was tempted to think that the spur to the switch burned out as quickly as the breaker tripped, but if it was a 16A I would have thought the breaker should have protected even 1mm wire given the fault was a dead short. (Didn't wire it in speaker wire did he )

Do you know where the spur starts (Back of a socket / junction box)? It's fairly important that it is disconnected, especially as it's now damaged.

PS I'm not an electrician so hopefully one of the regulars will be along soon.

 

[Gerbil4Ben]

The Spur is in 2.5 T+E.
I haven't had a chance to check where it is connected from yet but i suspect the back of one of the two double sockets.

Saying that, it could be from next door knowing the state the rest of the wiring is in.

 

[mikeyd]

I would guess as it's a flat the guy who wired it ran a cable from the wall lights to the switch than thought where do I get a neutral from?, so ran another cable from switch to nearest part of ring final as he didn't have access from above to the ceiling rose.

I don't know why the spur is now dead, but it is totally wrong. If it was my place I'd be turning off the breaker before bed.

 

[securespark]

You sure the fuse in the spur is intact?

 

[Gerbil4Ben]

i don't know about the fuse as i don't know where the feed is comming from but i'm goin g back tomorrow to have a better look.



Q:

If I can disconnect the spur from the ring can I then connect the feeds to the lighting circuit via the switch? and if i can How?

 

[mikeyd]

If I can disconnect the spur from the ring can I then connect the feeds to the lighting circuit via the switch? and if i can How?

Yes that is how it should be done. I think the problem you are up against is getting a neutral. The neutrals in the lighting circuit may be all up in the ceiling, and it's a flat so I guess access from above is not possible.

Some lighting circuits are wired taking the neutral to the switch back box, which would make it simple to do what you want to do, but I'm guessing not in your case which is why the original installer took a spur off the ring main/final.

Then again as Securespark has pointed have a good look for a fused spur. The original installer may have done the job half right (still shouldn't really have 2 circuits in one switch plate though)

 

[securespark]

I have come across instances where a 1362 fuse and the device at the board have failed together.