Odd wiring?

May 27, 2009 17 Replies

Changed some light fittings today, like for like, in a house perhaps 5 years old.



Strange wiring in the ceiling roses. I'd expect;



2 x blacks + neutral to lamp.
3 x reds joined.
1 x black with red sleeve + live to lamp.

They were wired;



2 x blacks + neutral to lamp.
2 x red + 1 x black joined.
1 x red + live to lamp.

So in other words, the switch cable was the opposite way around from the usual.



Thought it was a mistake at first, but all the lights upstairs & down were wired that way. It was a particularly neat & tidy job as well - workmanlike (lovely word) describes it, obviously deliberate. Customer has had the house from new, no work on lights since they moved in.



Obviously this way of wiring works, but;



Is it in accordance with the regulations and why would it be wired that way?



The Medway Handyman coughed up some electrons that declared:

Hi Dave,

Your former method is a valid and usual method for certain installations (ie there are many valid variants, but this is a perfectly normal one) (colour change excepted).

The method you found - it does appear, the way you described it, to simply have the switch cable the "wrong way" round.

However, the only technical error I can see is the lack of red sleeve on the live (normal parlance)/ line or phase (technical parlance) wire.

No particular reason it was wired that way, other than the installer was waiting to catch you out. It's not the best way as seeking to catch people out without a good reason is considered a "bad thing" (TM) but it's sound.

Seriously, it's more conventional to take the red or brown as the supply live, but it's not prescriptive AFAIK.

Stick a red sleeve on and you've corrected the only regulatory breach that seems apparent.

However, that's only based on what you've said. There may (or not) be other problems lurking. You didn't mention earths - are there any? There should be in a 5 year old installation (which should have been done to the 16th) and it does affect whether you should be adding any Class I accessories (ie needing an earth, not double insulated).

Cheers

Tim

'Earths ommited for simplicity' - yes there were earths.

The Medway Handyman coughed up some electrons that declared:

Sounds OK then :)

Unless anyone thinks of any weirdisms I didn't...

Cheers

Tim

You don't really need the red sleeve.. you open it up and can see the black is connected to the live. I would be more interested in knowing if the far end has a red sleeve.

The sleeve is very useful for remembering which is the switched live though. Makes you wonder how they knew?

You mean the switch end? I'm going back Friday to finish another job, I could have a look.

Sorry, knew what?

dennis@home coughed up some electrons that declared:

You do Dennis. IEE regs, correct identification of conductors. I'll quote it verbatim if you like, but, no matter how obvious it seems, it *should* be sleeved correctly.

IME, the red sleeve is fitted incorrectly sufficiently often that it must always be ignored, and would be safer if it wasn't used at all.

It often isn't used at all. I change loads of light fittings for people, very rare to ever see a sleeve. Another problem is that they easily fall off when you undo the terminal, I tape them in place with red tape before I undo them.

=========================================

Use a digital camera for reference and record purposes. It's quick, easy and almost fool-proof.

Cic.

Nothing wrong with that - although it ought to have a sleeve on the black.

Yup - basically the requirement is correctly identify the conductors if their natural colour is not correct. The only time you can't do this is to re-label a yellow/green striped earth wire.

It is rare to see a sleeve.

I always cut the exposed copper off the switched live when changing a pendant to a fitting so that when the sleeve falls off I know which cable it is. It is just a case of stripping it back again.

As to your odd wiring I know one old sparky who always wires lights up that way (with sleeving). He says that the first connection he makes is the black to premanent live and then he cannot get anything mixed up.

Totally legal.

Adam

ARWadsworth coughed up some electrons that declared:

Sorry - I only did my 4 day course a few months back - still indoctrinated! ;->

TBH, I'll probably stop using sleeves and start using a wrap of same coloured tape. Sleeves always end up falling off when people fiddle so even if it was perfect to start with, it probably doesn't stay that way.

Cue discussion on hellerman sleeves!

Cheers

Tim

On Thu, 28 May 2009 22:50:36 +0100, Dave had this to say:

Only at high speeds? :-)

I used to use Johnson's baby oil (or (my own!) saliva) for Hellerman sleeves, on coaxial jumpers.

Don't know, don't care. I was on the mechanical side :-)

We had our own problems in using vasaline, or silicone lubricants.

That could have been worded better. :-)

saliva) for Hellerman

Dave

I discovered in the late '60s that it also made the sleeves conductive. Multiway connector with all wires sleeved and you could measure the resistance with an ordinary AVO 8.

I tend to use a short length of heat shrink these days. Shrunk on it should last. I'll find out in a few years if it works.

Curses! Certainly the ones varnished with conductive (after several years) varnish.

Now that *would* cause confusion :-)

Dave

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