Be Excellent To Each Other

Hi everyone, especially those that may be good with electrics...

When we had our house rewired we had some wires put in for wall lights in the living room. The wires were left hanging while we decided which lights to have and as such, we left "unwired" in the light switch on the wall. The electrician at the time told me which wires to reconnect when we put the lights in but this was a long time ago... and now I can't remember.

Would anyone like to help me pick the right wire in the right hole?

You'll see from the picture that I have 3 blue wires in a cable connector (bottom of picture) now, I suspect 1, 2 or maybe all 3 of these need to go in a hole on the light switch... possibly the top left, since that doesn't have a wire in it? You can't really see from the picture but that hole has "com" written underneath it.

But why is there 3 wires when there's only 2 wall lights?

The switch by the way controls 3 lights in total. The big light and an outside light. These are all wired up and work fine.. I would just like to get the wall lights working.

I told the wife that I'd be able to do it with no problems... I've already been looking at it for 20 minutes scratching my head. I have a habit of electrocuting myself so I want to make sure I get it done right!

Paging Joans!

But seriously, did the stuff come with a handy dandy diagram?

One has to carry power in.

Fuck you bighead.

Oh, first off, drop the power for the entire house, unless you are sure the trip switch for the light ring is labelled correctly.

This is the first thing I did... Well, I've dropped the power for the downstairs lights which is what I'm working on.

I've learnt my lesson in turning the power off a long time ago!

Com is common, it's live (or brown). Although you only have two wall lights, if you have 3 different lights in total coming off the circuit then they will all have a neutral so that's why you have more blue wires. Are the other terminals on the switch labelled L1, L2 etc?

Unless you are certain that every light comes off the circuit labelled as the lighting circuit, kill the rest of the power.

My point is, unless that light switch you took a photo of up there is working and you can see the lights go off when you trip them, you don't know if the trip switch works for those lights or not.

Case in point, the trip switch for my living room power ring also switches off my fridge in the kitchen, and only half of the lights in the living room are on the living room light trip (the rest are on the dining room trip).

Hint: if you can't test it with a meter or something then you are not certain.

The other terminals are labelled 1W and 2W.. I happen to know this refers to 2 way switches but none of my lights are so I guess I don't need to worry about the 2w holes.

@Grim... I understand what you mean but yes. I'm sure that the lights have been killed by me tripping the main fuse board switch. When we had the rewire done I went around making a note of what switch did what with the electrician so I'm confident that it's all labelled correctly.

Thanks for not wanting me to electrocute myself though! It's much appreciated!

Right, slow down.

You've posted a picture of a wired-up switch. Does it not work as it is?

Next, you said there are two lights. And that's a 3 gang switch.
Are either of the lights controlled by another switch as well (you know, so that either switch can turn the light on or off)?

Finally you need to figure out if you've got the lighting ring coming into the switch back box (which is what it looks like) and if so which pairs that is. I'll help you do that next.

Ah I can read the back of it now you have explained what the terminals are. I hadn't used one like that before but I don't really get to practice on domestic stuff.
kalmar, why is the 1Way wired with brown on the right and blue in the middle? In both instances wouldn't it be acting as a switch live?

He said that the other two lights do work, so maybe it is the far right 2 way grouping that needs wired for the wall lights?

Done.



Yes and no. The switch will operate 3 lights in total... An outside light, the big light and the wall lights. Both the big light and outside light are already wired and work fine. It's the wall lights that have been left "unwired". The picture below shows the 3 light switches on the front of the switch.

Sorry.. I may have confused you here. There are 2 wall lights but they will both work off this one switch when it's wired. This is the only switch that will operate them.



I believe the lighting ring will be coming into the switch box as the other lights work off it. (i.e. The big light and the outside light)

It's normal practice to use the blue and brown in a twin cable to make the live circuit to the light. However what you are supposed to do is cover the blue wire with a brown sleeve to make it obvious that's what is going on. Someone here hasn't bothered, but apart from that it does look as if it may be wired up "right" so I'd advise caution before pulling all the wires out.

OK, gotcha. Which of the switches are the outside light and the big light?

edit: I guessed the same as Gilly says above but let's not guess

And be careful here, it looks like you've got more than one source of live in that box. Switch off all the lighting circuits before touching it, as Grim... said.

FFS just wrote a post and lost it.
kalmar, explain for me please. It looks like twin and earth, so I would have expected earth to earth, brown to common and blue to 1 way (possibly with brown sleeving).
What it looks like is the far right circuit has brown to common and 1 way, the central circuit has brown to common and blue to 1 way and the far left has so far got brown to 1 way which is maybe currently wired into the wall lights. Why?
Also, what are the three neutrals in the terminal block doing?
You can teach me so I don't have to stand around scratching my head when I need to do something in my house, since I don't get to practice on domestic stuff

I think it's a mixture! Hang on, I'll draw it

The left hand switch works the outside light and the middle works the big light.

So I think it's like this:


(earths omitted from drawing)

If so, you just need to connect a wire where I have put the dotted one (between the two COM terminals).

If I'm wrong it'll go bang or not work so we should try to confirm this first

Does that make sense Gilly?

I'm not as confused as I thought then because if I was faced with that switch then I would have daisychained a live to the common on the far left as well.
That makes perfect sense now, cheers kalmar. I was confusing myself about those neutrals because I was expecting to see one in the far right circuit so wasn't letting myself think about the actual lights.

Hmm.... so the 3 blue wires in the cable connector can stay can they?

Should it look like this... the red line being a new bit of wire?

Gilly, well it's not exactly best practice to put two different wiring types, with possibly two separate supplies into the back of one box, with no labelling or sleeving!

Anyway. Yeah I would check with a meter first that the wire we think is the supply live actually is, but you probably do just want to bridge those two COM terminals. edit: yeah, like that.

I agree with that too.

Ah... Kalmar, that dot on the bottom left of your picture that the 3 blue wires are going into... does that represent my cable connector? The one at the bottom of my pictures?

You could just pay £150 for a sparky to visit for 5 minutes (including a cuppa).

Yeah but I need to get used to thinking about it and not seeing things how I expect, especially given the state of some of the wiring jobs you come across in a forty year old factory!

Ok... done that, put that bit of wire in... and....

It doesn't work.

Is it still tripped?

EDIT-you could try taking it from the common in the centre and see if that makes a difference? I don't see why the way you have done it shoudln't work though. Make sure you have stripped the cable back enough to put it in the terminal 'til no copper is showing but it is right the way in, maybe you are clamping down on the insulation?

YAY!!!!

I've taken it from the common in the centre, as per Gillys suggestion, and it works!

Thanks to everyone for their help.. Especially Gilly and Kalmar.. I really appreciate it.

Now... my house isn't going to burn down in an electrical fire is it?

That's odd. Are the original two lights still working? I'd be wondering why the first attempt didn't work. Maybe the far right is wired wrong and 1W is live? I wouldn't really suggest doing too much though without testing equipment.

EDIT-sorry, I meant 1W not L1.

You're right.. I just screwed it back on and it tripped the switch.

I think I'm going to leave it now and let someone qualified do it. Lord knows what's wrong with it!

Just be careful of chemical fires.

Yes, it must be. I did suggest checking it first but I suppose if he doesn't have any sort of meter...

You mean the circuit breaker or the main RCD?

You've probably trapped one of the wires in the box when screwing it back, so that it's cut through the insulation and is touching the metal of the box.

I wouldn't have used live from that middle switch by the way, it could be a completely different circuit!
Use the other side of the switch which didn't work the first time.

Yes, the joined neutrals on my drawing represents the screw connector thing.

What did you screw back on for it to trip, the face of the switch? The wire might not have been clamped down securely and could have pulled out a bit. Does the cover of the wire look ok or is it nicked anywhere?
It helps if you position the face in an almost closed position while you arrange the wires, then open the face again and give the terminals another wee nip up before you close it properly and screw the face back on. I don't know how many times I have wired something and tugged on it to make sure it won't come out, only for it to come out at the slightest provocation of whomever is checking my work This of course led to me going the other direction and on Monday I wired up a light while I was 50ft up in a cherry picker and determined it would stay wired (so I didn't have to go back up), I horsed the screw right up. The electrician I was working with went to give the wire a wee tug and it came right out, leaving behind the bit of copper clamped so hard it had snapped the wire

How much do meteres cost anyway,aren't they quite expensive?

About a fiver from Maplin! Well worth it to avoid confusion like this

Hah, ok. Worth an investment then, yes.

Five whole pounds? Good lord...

This is a lot harder than I thought it would be though... and I wish I could say I'd had a good time while doing it.



What do you mean by this?

We guessed that the COM terminal on the left-most switch was the live one, because that's how anyone with any sense would have done it But it's not, so it must be the other one, 1W or whatever it's called.

The reason I would say use that rather than the middle one is that it's quite possibly on a different circuit breaker - what this means is that you've got current returning to Neutral via an unexpected path, which is guaranteed to lead to confusion or possibly shock for someone working on it in future.

Or, worst case, if the fuse box has two seperate RCDs (as they do nowadays) and these circuits aren't on the same one, this will randomly cause one breaker to trip as the load is unbalanced.

The first time you tried you wired it into the common and it didn't work. Try wiring it into the other side of that switch, so the 1W that is associated with that common. The live has probably been wired in there by mistake.

FAKE EDIT- kalmar, what made you think in the first instance that it was the one at the outside that was the correct one? What i mean is, how did you know to go for that one rather the centre one?

Simply because I think that the middle switch and wire pair are nothing to do with the rest of it.

The neutral for that light is not going back to the screw connector, as our new light is, and that live may be coming from a different circuit breaker. So, I would leave it out of the equation altogether.

To be honest, TV, if you're getting worried about it there's no shame in calling an electrician. He will simply make tutting noises, check with his meter and then do what we've said above, but I don't want you to be doing stuff you're nervous about, and we have been guessing in the dark slightly (heh) without verifying it with a meter.

Yeah I see that now. I was looking at it and thinking that I couldn't see any of those neutrals going to the terminal block so I couldn't tell which was on the same circuit but again I was just looking at what I could see and not thinking about what I couldn't see. I see now that from the existing circuit on the outside we've obviously got the switch live going to the lamp and then the neutral returning to the terminal block but in the middle the neutral is leaving so must be seperate. Thanks kalmar

I think this could be the sensible route. I was going to ask you how to fit a spur from the fuse box to plug in a house alarm but I think I might get an electrician to do that too....

I also need a plug fitting in the spare bedroom so I could kill 3 birds with one stone here... rather than kill one Vision with one light switch.

Be safe, Mr Vision!

You might need to get the house electrics retested to allow you to do this, due to STUPID FUCKING RULES.

[edit]Assuming you meant 'socket', of course. If you can't wire a plug, hand in your man card now.