Light switch wiring nightmare

N

NotSoFast

Just thought I'd share what I found when I went to replace the failing dimmer switch for the en-suite this morning :eek:

View media item 57865 View media item 57867
There are five cables going into the box. so it looks like the four downlighters and extractor fan are all wired directly back to the switch. The black and red cable suggests it was done when the house was built. Is this normal? It doesn't seem very professional to me :confused:

I was going to change all the light switches in the house but I'm not so sure now :D
 
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It's busy, but.......

WHY HAVE YOU GOT A DIMMER FOR THE ENSUITE?????????

And doesn't the dimmer control the fan, too?
 
N

NotSoFast

I haven't any more :D The previous owner put it in. I asked about it when I viewed the house. They said it was for when they got up for a wizz in the middle of the night :LOL:

The switch controls the fan via an isolator switch. I've no idea whether it affected the fan operation as I only ever had it turned up to max.
 
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WHY HAVE YOU GOT A DIMMER FOR THE ENSUITE?????????
Well my mate has a dimmer on his bathroom lights - the key may well be "downlights". With 4 torches set in the ceiling, it can be rather bright if you want to just lie there for a soothing soak ... with a spotlight shining in your face and you can imagine Herr Flick telling you that "You vill tell me ..."
Having a dimmer means you can tone it down a bit.
And doesn't the dimmer control the fan, too?
I'd imagine most fans with a timer will only use the light circuit as a trigger. If they see more than a certain voltage then the timer will turn on. So unless you only use the lights at a very low setting (possibly lower than the dimmer goes), the fan will still run automatically.
 
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No it didn't.

How could it?

This is Part P:




Where does it say anything about who may or may not do electrical work?
 
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The only thing particularly wrong in the picture is that a dimmer switch has been used. No good in conjunction with a fan. And a bit chunky on that box full of wires.

It is quite normal to have so many wires at a switch.

I would estimate that originally there would have been a normal switch there, and that someone has replaced it with a dimmer.

Fit a normal switch.

There should only be two terminals used on the switch.

Observe and remember which wires go in which hole, and copy this arrangement on the new switch. As long as you keep the two sets of reds (and yellow) in the same 'bunches' you should be ok. It doesn't matter which way round the 'bunches' go in the switch, as long as you use COM and L1. Switch markings can vary though.

Remember, if the new switch is metal, you MUST connect earth to the earth terminal.
 
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Like that. So many wires crammed in the box you can hardly fit the switch on :eek:

I'm no electrician but if that was my work I'd be truly ashamed.
Indeed. Some years ago I went to look at a new flat (conversion of old building). There were many reasons I didn't buy it - I didn't like the plumbing (all plastic pushfit buried in the stud walls), I didn't like the flooring, and I especially didn't like the wiring. Next to the front door of the flat was the box for the switch (the electrics were still being done). A single shallow box (16mm ?), for a 3 gang switch, with at least 5 cables going into it just like that first post. Absolutely no way on earth that could be done to an acceptable manner in my opinion.
It would have required all the wires to be cut back to just the right length as there'd be no room to leave any slack/spare, and they'd all be crushed in behind the switch which is just inviting faults later when the insulation fails under pressure.
I thought bodges like that were reason they stopped DIYers doing electrics :p
It was indeed why restrictions were introduced - but DIY was never completely stopped. If you look at Schedule 4 of the 2010 BR (Schedule 2 in the 2005 BR) then you'll see that there is still a wide scope of work that is allowed without notification. However, even if the work is notifiable then you can still do it as DIY - you just have to notify your LABC and pay their fees (often more than paying someone to do the work for you).

Needless to say, certain elements of the industry were quite happy to keep pushing the "no DIY allowed" message. Only a few weeks ago I sat through a presentation where someone from <one of the approved schemes> went through a whole 1/2 hour presentation using very carefully chosen words designed to imply that only their members were allowed to do electrics. Very carefully chosen words, I wasn't quite able to shout out "you ****ing liar" - but very very close and someone who didn't know the law would most definitely have come away with a false understanding.
 
N

NotSoFast

The only thing particularly wrong in the picture is that a dimmer switch has been used. No good in conjunction with a fan. And a bit chunky on that box full of wires.

It is quite normal to have so many wires at a switch.

I would estimate that originally there would have been a normal switch there, and that someone has replaced it with a dimmer.

Fit a normal switch.

There should only be two terminals used on the switch.

Observe and remember which wires go in which hole, and copy this arrangement on the new switch. As long as you keep the two sets of reds (and yellow) in the same 'bunches' you should be ok. It doesn't matter which way round the 'bunches' go in the switch, as long as you use COM and L1. Switch markings can vary though.

Remember, if the new switch is metal, you MUST connect earth to the earth terminal.
Thanks. The switch has been replaced with a nice, normal MK switch. :D

No it didn't.

How could it?

This is Part P:




Where does it say anything about who may or may not do electrical work?
OK. Poor choice of words on my part. However, your average DIYer isn't going to read that. They're going to Google "Part P" which throws up plenty of industry sponsored misinformation that suggests DIYers cannot do their own electrics.
 

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