house wiring

[Stephen]

Hello,

I have moved house and I was changing some of the light fittings and light switches to prettier ones. I was surprised to find that downstairs the lights are wired with stranded wire. I hadn't seen this before. The colours were unusual as well: one light switch had red, blue, and white. What wire is that? Should it be rewired in standard colours and cable do you think?

There's also a loft conversion but the lights and sockets all seem to come off one FCU. That seems strange. Couldn't they have kept the lights separate to the sockets by going off the first floor lighting circuit?

Thanks, Stephen.

[Etaoin Shrdlu]

Might be one end of a two-way switch setup (e.g. top and bottom of stairs) , but I think that's supposed to be something like red blue yellow.

[Brian-Gaff]

I bet if you looked at a lot of houses with different vintages and different bodge histories you would find many strange things. To me safety is the main thing in daily use, and of course some record of what wire wwas used and how it was connected. Sadly, although this may well have been recorded at the time, over many years and sundry owners its been lost. I think this house still has red black and green everywhere, but at least that was once a standard. Stranded in light switches is dodgy as it only takes one strand to touch something else and things go phut. Brian

[tabbypurr]

how do we know, we've so little info to go on. If colour determined safety a lot of people would be out of work.

Both off same fuse? If so I'd investigate more to see if its safe.

NT

[Dave Plowman (News)]

Before about 1970, lighting cable was mostly 3/0.029". Was there an earth conductor present - and more to the point is it connected at both ends? There was no requirement for an earth on lighting circuits in those days - although the cable itself might have had one.

The triple cable is more likely red blue and yellow. That was often used in two way switch circuits - or sometimes where you'd have two switches in the same place with just one cable run.

If the wiring is in good condition, no need to replace it. But do have that earth circuit checked out.

[Martin Bonner]

By "stranded", do you mean 7 wires wrapped around each other? If so, that used to be the standard way all wire was made - made things much more flexible when fitting into back-boxes.

Red, *yellow*, and blue were the old colours for three-core-and-earth (typically used in double-switch lighting setups).

... and a quick search for "uk electric cable colours" shows that white was an acceptable alternative for yellow.

So, it's old - but that doesn't mean it's dodgy.

[newshound]

Agreed

No, but lights and sockets on the same circuit in the loft should raise small alarms.

[Andy Burns]

Particularly if the "prettier" switches and fittings you're intending to fit are metal, not allowed without an earth.

[Mike Clarke]

For a lighting circuit it would have been 3/.029, i.e. 3 strands of

0.029" diameter.

[tabbypurr]

It certainly raises questions. Its not unsafe to provide 5A sockets, but if part of a proper loft conv rather than just a socket in an attic for a lig ht it does indicate some surprising short cuts, raising the quetion of what else was done and why. 5A sockets aren't always a bad thing, but...

NT

[John Rumm]

The more important question is what is the effective cross sectional area of the wire used? What is the rating of the circuit Fuse / MCB?

Its quite common for a "done cheap" loft conversion or extension. Sometimes if the existing lighting circuit lacks an earth, its the only legit way of doing it without installing a complete new circuit (which would be preferable really)

Perhaps, but see comment on lighting circuit earth above.

[Chris French]

Where did the 5A sockets come from?

The Op said the lights and sockets are fed from an FCU, which suggests they are fed along with sockets (presumably 13A) from the ring main

[ARW]

White was removed from the regs and made to be yellow in 1966.

And there certainly will be no earth on that cable.

[Andy Wade]

Yes to both points, also old lighting was commonly in 1/0.044 rather than 3/0.029 (so was single strand).

[Dave Plowman (News)]

Probably depends. My experience was 3/0.029 was more common than the single strand stuff. So may be a regional thing.

[Stephen]

Some lights have earth, some do not. Every room seems to be different!

Yes, I knew red, blue, yellow, was the old black, grey, brown but I wouldn't have thought the yellow could fade to white could it?

Will do, thanks.

[Stephen]

I didn't know that, thanks.

[Stephen]

Yes all off a 13A fused spur.

That's the strangest thing. I can see how some of the wiring is old and may have been done when regulations were more relaxed but I would have expected a recent loft conversion to be more regulated. The solicitor (when conveyancing) had all the documents from the council approving the work, so either they didn't notice or was it acceptable a few years ago?

[Stephen]

But the upstairs lights appear to be in red and black T&E,l whereas the downstairs has the older stranded stuff without earth, so I think they could have taken the loft lights off the upstairs light circuit.

To answer your other question, ground and first floor lights each have

6A MCBs in the CU.

Thanks, Stephen.

[Dave Plowman (News)]

But are you sure that earth is connected all the way back to true earth?