>bzzzert<

[torkell]

Do you know that, as of April next year, the mains wiring colours will change for the UK? In fact, any electrical work now should use the new colours already, but you're still allowed to use the old ones if you've got left-over bits of cable for now.

Current colours: Red, Yellow and Blue denote the 3 phases, Black denotes neutral, and Green (sometimes with yellow stripes) denotes earth. And this is all very well and makes pefect sense as long as you're not colour-blind. If you are, then electrician is one of those jobs which is not for you.

Until the EU got their way, at which point they decided to change all the colours. Oh, and you don't refer to the phases by colour anymore - you label them "L1", "L2" and "L3" instead. So the new colours are Brown, Black and Grey for the phases, Blue for neutral, and Green with Yellow stripes for the earth.

Have you worked out the fun part yet? This table might help:

	L1	L2	L3	N	E
old
new					//

Comments

[pewterfish.livejournal.com]

Depending on the phase angle between the three phases, it could get ... interesting if you attempt to follow the old colour-scheme. That said, all the wiring I've ever seen in domestic electric circuitry has been brown-blue-green...

Of course, I haven't done THAT much... But I've never seen a red-black-green.

Nonetheless, interesting times, and all that, eh?

[torkell]

For the past few decades all single-phase wiring from the plug to the power-sucking-widget has been with the new colours (brown-blue). The core wiring (i.e. from the consumer unit to the socket) for anything done before this year is generally red-black-copper (the earth usually being unsleeved in the wire). It's only been the past year or two that the new colours have really become available, and in fact it's getting hard to buy the old colours now. So unless it's a new installation you'll almost certainly find the old colours.

I'm not actually sure what happens if you swap phase and neutral. I'd imagine most single-phase stuff wouldn't care (stuff like light bulbs doesn't care *what* you feed it as long as there's power there, and modern switching power supplies can sometimes be run off anything from 90v to 250v AC or about 110-300v DC.

I'd guess it would get more interesting with stuff that actually uses all 3 phases. There was one tale I came across of when someone swapped a pair of phases to an olden days hard disk, and the motor ran backwards (which resulted in the heads going down instead of up with the resulting Bad Things that happen when hard disk heads impact the platters).

[pewterfish.livejournal.com]

Mmm, haven't seen much domestic wiring other than widget-to-socket, so it's possibly not surprising that I haven't seen the other colours.

Swapping phase and neutral shouldn't make any difference, assuming it's going through a decent PSU. Might have amusing effects on older televisions and monitors.