ceiling pull-switch wiring question

I'm replacing a 1-way ceiling pull-switch in my hallway which controls a light outside my front door. The old one had one black and one blue wire, twisted together in the COM slot, and one red wire in each of the other two slots. A fourth slot was empty.

I don't know why it was wired like that, since the switch is 1-way only. Nothing else is controlled off the switch.

But that's how it was wired, and until recently it worked fine.

How should I wire up the new switch?

Thanks!

Harry

Reply to
Harold Davis
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Harold Davis wrote in news:XnsA357D4293B51Fharolddavis@78.46.70.116:

Correction: the old one had one black and one blue twisted together into ONE slot (not sure which one), one red wire in each of two other slots, and an empty fourth slot.

The old switch has one of its slots labelled COM and no labels on the other three.

My new box has got COM-L1-L2.

I started by twisting black and blue together into COM and putting one of the reds into L1 and the other into L2. No light. No fuse blown either.

Someone is advising that I should join black and blue in a junction box, put one red into COM and the other into L1. Does that sound correct?

Thanks!

Harry

Reply to
Harold Davis

So maybe you have a two way switch then? Brian

Reply to
Brian Gaff

A simple continuity tester wil show what switches to what, I'd have thought. You do not say the old one was wired a as the two reds, one is the live and the other the light. To be honest it sounds just a little like a bodge, so if you have a meter you need to find what the wires carry and what they are for. Brian

Reply to
Brian Gaff

The old switch is 1 way, the new is 2 way. Ignore the new L2 connection & the other 2 connections are the same as the old switch. And it doesnt matter which way round they are.

NT

Reply to
meow2222

snipped-for-privacy@care2.com wrote in news: snipped-for-privacy@googlegroups.com:

Thanks for this. The old switch was used as 1-way but the actual switch box had 4 slots and the black and blue wires were twisted together into one of them. The nearest I can get to configuring the black and blue the same as in the old switch is to join them in a junction box outside of the switch box. Apologies if I am missing something, but am I interpreting you right? :-)

Thanks!

Harry

Reply to
Harold Davis

The twisted pair were probably in a blank hole the others were active and switch wire. some switches have a blank hole not connected to any thing to join two wires together

Reply to
F Murtz

If it had 4 different connection places, presumably 1 was an unconnected pa rking spot. Black + blue sounds very much like a neutral connection. I'd co nnect them together using a screw connector choc block thing - or better ge t the multimeter out to confirm whats going on. I cant think of any reason to use an external jbox.

NT

Reply to
meow2222

That should have blown the fuse. Is there any power to the switch? Did the old switch really have a COM terminal?

I would say it sounds correct. And by junction box I assume you mean a piece of strip connector. But as you first attempt failed to blow a fuse then I can not see how this would work.

Reply to
ARW

If power was fed into L1 and out from com, putting neutrals in L2 wouldnt blow anything. But its not good practice. IIRC it was outlawed in the 1930s along with the Carter system.

As for why the thing isnt working, how do we know. The OP needs a bit of investigating skill, and doesnt have it. Maybe someone will explain how to test what each wire is.

NT

Reply to
meow2222

IF - but the OP said he put (what we assume are the neutrals) into COM. That would blow a fuse depending on the on/off position od the switch. Putting the neutral into L2 and permanent live into L1 can cause a fuse to blow due to switch bounce/ the fact that a light switch is not designed to be a make before break switch.

Well either there is either no power to the switch or he did not put the neutrals into COM

Reply to
ARW

Or had a loose permanent live connection!

Reply to
ARW

or various other possibles

NT

Reply to
meow2222

If it weren't for the mystery as to why the neutrals between the old and new colour coded cabling were joined on the switch contact marked com, I'd have to guess on it being a tee from the lighting circuit going to the outside lamp having its live (red and brown wires) intercepted by the switch contacts.

Going by your description, that switch should have been blowing a fuse or tripping the lighting circuit breaker every time it was turned on. The contact marked com is the common pole that gets switched to either of the other two contacts when both are present. IOW, com does not mean an isolated connection that can be used to common or join two wires together. With a switch (1 or 2 way) the com is one of its connections.

I think pretty well all modern wallplate light switches are single pole double throw changeover type. It simplifies the inventory and cuts the costs of production by rationalising two seperate production lines into one. The resulting light switch can be used for either single or two way switching (or as the end switches in a multiway switched circuit).

If you're going to fit a single pole switch, whether 1 or 2 way, you'll need to join the black and blue wires independently of any of the switch terminals. Alternatively, you could fit a 2 pole 1 way switch where both live and neutral are switched which will allow you to terminate all four wires on the switch terminals.

Reply to
Johny B Good

He didn't actually say neutrals (just black and blue) the black could be a switched live missing the red sleeving, rather than a blue to a lamp holder the blue could be from an old colours 3+E cable, I don't think we know enough about how it was beforehand ... cameras are wonderful things ...

Reply to
Andy Burns

snipped-for-privacy@care2.com wrote in news: snipped-for-privacy@googlegroups.com:

Thanks! I connected them using a terminal block and choc box and everything now works fine! :-)

Harry

Reply to
Harold Davis

"ARW" wrote in news:lohjjb$qfs$ snipped-for-privacy@dont-email.me:

Actually it did blow the fuse. For some reason I was listening for a switch to be tripped, but actually the fuse box is old-style with fuse wire and porcelain and in fact the fuse did blow.

Harry

Reply to
Harold Davis

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