Wiring disaster behind a hall rose

[Xan]

Last week we had our hallway re-plastered and the old rose was simply loosened to get behind and not really looked inside.

Today I popped to the shop and got 2 new roses for both the hall lights (there is 1 top, 1 bottom, controlled by a 2 way switch top and bottom also).

In my ignorance I committed the cardinal sin and didn't take note of where the wires where originally (too be fair to myself some where just twisted together and not even screwed into anything, just left loose inside the rose that shorted out the whole upstairs lighting during the re-plastering).

Anyway I'm no electrician but I've done my best to guess which wire was the switch and which were part of the main loop.

After some swearing and scratched fingers later trying to wrestle the old stiff wires into their new home I turned the power back on, popped the bulb in and turned the light on. that just created sparks from the rose but nothing blew.

This is what I ended up with (apologies for the size, but at least you get a clearer view than i had when working on it ):

I assumed the red and black from the white sheath were the switch (thus the earth hadn't been tied in from that previously... I hoped).

I know it's not much to work with, all the wires are in a cavity space that is freshly plastered over and can't be accessed any other way. House was built around 1890, so it could certainly do with a full rewiring, but we just can't afford that and need to make do with things as is.

From what I can see the bottom light only has a single wire running into the rose. Would that mean another live and neutral that are grouped together with the main bunch should be moved out with the switch?

It's dark now so I'll have to leave this until tomorrow as I don't have a decent torch to be messing around with wiring. If needed I'll just get an electrician, but I'd rather save on the expense and just take my time with it if anyone can give me a safe methodology to use.

Any help and advice much appreciated.

 

[flameport]

You need to properly identify the switch wire, guessing simply won't work.
The earth wire in the white cable needs to be connected to the others.

that just created sparks from the rose but nothing blew.

In that case you really should get an electrician in, since creating sparks without causing a fuse or circuit breaker to operate suggests serious problems which could easily lead to a fire.

 

[bernardgreen]

Is that mesh behind the rose metal or plastic. If metal it might need a bit of trimming to make sure there are no sharp edges or points that may pierce the insulation on the wires.

 

[JameZZ]

To see if the white cable does go to the switch (I amuse their is only a switch downstairs for this light?) unscrew the switch and see if the cable in there is white (make sure the powers off!).

It is probably sparking because the connections you've made are not very well terminated, you need to trim the copper so it fits into the connector well and don't twist the live (red) ones it makes a bad joint. Bad joints cause fire & the earth of the white cable needs connecting to the earth in the rose. Failing that the cables could be damaged above the fitting which is dangerous! If it still sparks call an electrician asap...

 

[sparkwright]

Is that mesh behind the rose metal or plastic. If metal it might need a bit of trimming to make sure there are no sharp edges or points that may pierce the insulation on the wires.

Plasterers scrim tape, I would have thought.

If you are certain you have wired the light up correctly, and all works, you may like to consider tidying up the wiring.

You should check the stripped copper ends are securely connected - every time you connect and reconnect a wire the end becomes weaker and weaker. You will need to cut off the stripped ends, and re-strip them back to sound, new copper.

Bad connections will cause sparking.

The wires are a bit 'platted' and messy.

That cut off earth wire need investigating and connecting, with some green and yellow sleeving over it.

Get a professional in if in doubt.

 

[securespark]

creating sparks without causing a fuse or circuit breaker to operate

I did that. In the dim and distant past before I knew any better, I did not isolate a socket correctly. I came to chop through the live & neutral conductors and there was an almighty bang and a flash, but the 3036 was still intact. EFLI was acceptable.

 

[ban-all-sheds]

the 3036 was still intact. EFLI was acceptable.

More intact and more acceptable than your cutters were, I imagine...