I bought some SWA cable to use in the garden. It has three 2.5 mm2 cores, with brown, black and grey insulation.
The label doesn't say which colour to use for what but it does have an new/old conversion chart.
new old brown red grey yellow black blue
I think brown is live, but I'm not sure what to do with the others, because I've only used twin and earth until now.
Which one is what?
Brown is live, grey (sleeved blue) is neutral, black (sleeved yellow and green) is earth.
It's 3-phase cable without a neutral.
brown = red = L1 grey = yellow = L2 black = blue = L3
If you are using it for a single phase+neutral supply then, strictly speaking, it is the wrong stuff. It would be a pity to waste it, so I would suggest that you use it as follows:
brown = live black with blue sleeving = neutral grey with green/yellow sleeving = earth
Note: you must sleeve the conductors at both ends.
You must also earth the armour (via a proper cable gland for wire armour, but at 2.5mm2 I suspect that you have braided cable so cable entry is via a stuffing gland and take the braiding to an earth terminal).
To be fair, Bolted was spot on with his reply.
Suggesting that grey is L2 and black is L3 is incorrect. It is the other way around.
The OPs conversion chart that came with the wiring is also incorrect.
Adam
?? Sorry - I can't see it on here.
Correct - I was too quick & posted without thinking. :-(
Now that's just plain naughty!
I don't know what Bolted posted, but (apart from my new phase colours messup) I'll stick with what I said. Since the (insane) harmonised colours appeared I've always liked bl(ack/ue) and gr(ey/een) for neutral and earth! I'm not sure if there is actually a standard for using 3-phase cable on 1ph+n+e - I doubt it - and sleeving is ok. :-)
Have you tried to get brown, black and grey indicator lights for switchgear panels? Mad, I tell you! :-)
"sleeved" - electrical tape will do?
The regs say that you should use "permanent" marking. That includes sleeving and thread-through cable markers. If you use tape - which can eventually fall off - then you should probably also use small tie-wraps to give it better security.
Incidentally, I found the following to back up my choice of cable colours:
a three core for a single phase supply the NICEIC advise that black should be sleeved and used as earth green/yell and the grey as neutral
sleeved blue ,but when installing to the old coloured board do i sleeve the neutral as blue or as black ? also on some jobs the grey is used as the earth,and the black as the neutral I should'nt be confused but i am
My god - there's noting like stable standardisation is there. Do the reg say we must rise at 10:30 and chant "Prescott's my hero" three times? Madness.
On 10 Aug, 23:28, dave wrote:
Actually the colours were agreed a ?decade? ago. Prescott didn't have a hand in them.
It has some interesting side-effects...
- Harmonised look wonderful (not) under low light or LP sodium light
- GY/BK/BR has Black typically Earth on 1ph, but Live on 3ph
- 3c+E smoke does have "standard colours" but not 3c-SWA
- Line being the new trendy word for Live
There are some other odd SWA options - for example 5c can be had with all white cores or BR/BL/BK/GY & Gr/Ye. The latter is actually useful for two switched LN feeds (Shed + Lights) with Gr/Ye forcing anyone who comes along in the future to only screw up LN rather than Live that which should be Earth.
Be glad, we still manage to keep...
- FTE with bare CPC - rather than French green insulated CPC
- Ring final circuits - rather than Radials (because we have fused plugs)
- UK wiring accessories - imperfect, but better than most
A positive of Ring FC is dual CPC routes, a negative is unbalanced ring & a broken rings means each leg is protected by 32A CPD (above cable CCC).
The real problem across the board is legislation which specifies nothing, permitting corporate marketing departments to write whatever they want tied to their revenue targets under the guise of "stakeholder society". Government is usurped completely by business, business is not a democracy, all in order to create a chain of men in brown overalls so men in blue suits & BMWs can push products which are often utter crap. The new environmental linked BR will turn out to be a complete joke with people avoiding CWI or Loft insulation to avoid ridiculous "law of dimishing return" improvements on future extensions. Again, as usual, from H&S to BR to Electrical the concept of Cost Benefit Analysis goes out the window through second rate politicians, civil servants and essentially "nationalise the demand" corporations. Forget 1932 protectionism, we are generating a Centrally Planned Protectionism which in the end will result in a cost-laden economy that snaps. Legislation can reach a point where the original aim is so lost that it collapses. Not MP Expenses but Corporate writing Gov't policy will be the stink eventually. I even recall ? Watchdog? years back where companies boasted how they were writing government policy. Next going by agricultural land prices will be a "rural agricultural economy", N% of product must be locally grown. Goldman Sachs & TARP money created the recent oil run, next will be the food run - all under the guise of environmental lobbying no doubt by supermarkets who can inflate margins. The most profitable UK companies are grocery warehouses with 2-3 national supply; says a lot really.
At least the wind turbine micro-generation macro-revenue nonsense died.
...
That's the only kind I've seen for sale in DIY shops. (I imagine electrical specialists could supply something with a different colour scheme.) Some years ago when I was thinking about getting some to use in the garden, I noticed they were only selling the same thing, but in red, yellow, and blue. (I remember because I thought it was strange then.)
Isn't three-core-and-earth cable (the kind you'd use for connecting two switches to one light) sold with three-phase colours too?
Hadn't actually considered that. What do you use? I suppose for black you'd have to use some sort of non-emittive indicator like an dolls- eye.
Owain
If so that would be correct in the usual wiring configuration, as all three wires are some version of live or switched live, so should all be in phase colours.
Using phase colours as neutrals is bad, using any colour other than g/ y for earth (even if sleeved) is very bad IMHO.
Owain
Yep - you're right. For single phase supplies it's assumed that you will use 2-core cable (brown+blue) and use the armour as the protective earth conductor.
3-core cable will be brown+black+grey and is used for 3-phase supplies (usually motors or transformers where neutral isn't required). Once again, the armour is earth. 4-core cable has brown+black+grey+blue cores for 3-phase & neutral supplies. 5-core cable has brown+black+grey+blue+green/yellow cores. Used like 4- core but with a separate earth conductor.You can also get similar cables with all white cores numbered from 1 upwards every so often.
You're also right about the lighting cable. I remember seeing it in r.y.b
+e, but I haven't come across a harmonised colours version - I assume it exists, but most people seen to use 2 runs of twin+earth. It's probably cheaper and easier to get.
Its easy enough to get, and comes in the harmonised colours now.
I had to think about that for a bit. If it's a "loop-in" circuit, where L, N, & E go from the supply to the ceiling fixture, and then you connect live and two switched lives (and earth, of course) between the switches, that's true.
But if you take L, N, & E to one switch first, then run three-core-and-earth to the second switch, then switched live, N, & E to the light, then the cable between the switches is carrying two switched lives, one neutral, and one earth.
The second kind is the only one I've done, but I guess it's probably not as common.
I agree that it's better not to re-sleeve, but sometimes you have to work with the available materials.
It's wire armour, and Wickes sells the glands for that, on the shelf over the cable.
Thanks.
I saw some "heatshrink sleeving" in assorted colours in B&Q, but no instructions on the outside of the pack. Does anyone know how much heat you need? A hair-dryer?
(Not a blowtorch!)
Tiny hot air guns are used in the lab. Hair dryer is not hot enough. Blowtorch is often used outdoors, but you don't put the flame on the sleeving -- you wave it some distance away so temperature is well below that of the flame. I sometimes do it over a gas hob (again, some distance above the flame). Can also use the hot side of a soldering iron, but that's fiddly to get full shrinkage.
You can get heatshrink in at least two temperatures for shrinking. I have used a hair-dryer, but I had to cup my hand over the air intake to warm it up a bit, not too dangerous short term unless the mrs finds out and hits you with it. Usually I use a soldering iron that's been removed from it's supply so the heat isn't at full heat ~300C as the shrink temperature is about 80C to 110C I think, and will probably shrink to half it's diameter. If it's too hot the sleeving may melt or split. A lighter or match can be OK with care as mentioned, some heatshrink is non-flammable
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