I was thinking about replacing a lightswitch but when I looked behind there are three red wires - one joined to one terminal and two joined to the other. There is also a black wire that just seems to be passing through. This is a bedroom with one light and one switch. I always thought the live travelled from the ceiling to the switch and back again and the neutral stayed in the ceiling. Any wisdom?
Almost sounds like loop through the switch wiring
but if there are 3x red, you'd expect 3x black too, or something funky is going on ... photo(s)?
These days with smart switches etc. the neutral is often routed to the switch back box so that the switch can get live and neutral for power.
See 2 plate method.
I'll try and get a photo in daylight. There are other peculiarites (such as two switches that do not seem to do anything). I am trying to organise a full inspection and wiring check.
I think the fact that the wires are red and black rules out this possibility.
Could at one time been a ceiling pull cord switch above a bed with either the wall switch or the ceiling switch being able to turn on/off the light. If the ceiling switch has been removed the wall switch wiring may have been modified (without removing any wires).
I have wiring behind a light switch like that.
It's a convenient route to get power for lighting from one floor to the next.
That is an interesting suggestion. I'll ask the electrician to check it out. I am hoping he does not find any VIR cable as this is apparently bad news.
That's interesting too. I shall could check the breakers in daylight.
When replacing it swap one wire at a time so each wire is connected in the same place it was (this assumes like for like replacement of the switch). Although this is a DIY group. if totally uncertain how to proceed get an electrician in, IME electricity is not to be Shpxrq(ROT 13) with
I very much agree with your latter point. I am arranging for an electrician to carry out a wiring check. I probably want a new RCBO equipped consumer unit (at my last flat at one time the computer crashed out when the washing machine started the spin cycle).
I have looked. The upstairs and downstairs lights are on separate circuits.
ME:- Got a belt from an old Dancette record player I was faffing with (was only eight or so) I hadn't unplugged it from the wall (didn't know any better). Was sticking my hands and various tools into its innards when B L A M
240 Volts up one finger and down the next(if it had been across the heart don't think I would still be here). Even 'only' across my fingers still managed to throw (or rather it energised my muscles and I threw myself) me across the room. Took me the rest of the day to stop crying and shaking. Have been wary of electricity ever since. E.G. Turn the whole house off rather than a specific circuit or at the very least check, check and check again that any circuit I am working on is actually dead.
I got caught out by a reel-to-reel tape recorder - unexpectedly, the erase head was mains powered.
I got a belt from a reel-to-reel tape recorder as child. I forgot that even when the main switch on the tape recorder was in the "off" position, there was still power to the input terminals on that switch! I still have the two marks on my finger that happened to brush the live and neutral where the wires were soldered to the switch contacts.
I also got a belt much more recently from a GU10 light fitting. I was gradually changing the fittings in a room that has a grid of GU10s in the ceiling. I'd been really good about turning off at least the wall switch and ideally the MCB in the fuse box. I'd finished for the day, then my wife said "Can you do that one as well". The crucial thing is that the lightbulbs were Philips Hue - these can be turned off within the bulb housing (via a smartphone app) so it is possible for the bulb to be off even when there is mains to it. Guess which idiot forgot that and assumed "no light" means "switch is off at the wall". The shock was the mildest mains shock I've ever had, probably because the RCD tripped within the stated 30 msec; all previous shocks were in the days before RCDs so the power just carried on until I ripped my hand away.
Could be "loop through switch" style wiring:
So are mine.
The point I was making is that power to my upstairs lighting circuit is routed via a switch from the floor to the ceiling.
The conductors run behind the switch, except the live feed is teed off to the switch and a single continues up the wall and along the ceiling to the rose.
Okay, thanks. I get it now. My conclusion is that I want a proper electrician to check the wiring and consumer unit and to make appropriate recommendations.
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