How are the methods in England? Do you use romex, and BX cable? Is coduit ran in the walls?
The Romex name isn't used here, but a similar PVC-sheathed cable is the most common method for wiring residential systems. It's commonly called "twin & earth" (i.e. 2 conductor plus ground).
Steel conduit -- either set into the wall or run on the surface -- is common in industrial applications, but would be far too labor-intensive and expensive for residential work, although you might find it in some very old (1930s) residential wiring. Wiring from the 1930s/1940s may also be a lead-sheathed cable.
These days we also have PVC conduit, which is common in light commercial systems, and also useful in domestic situations where a little more protection is needed for the wiring, such as in a shed or garage.
[This message has been edited by pauluk (edited 06-24-2003).]
#137349 - 06/26/0309:02 PMRe: Wiring methods in U.K.
The twin-&-earth -- "T&E" -- is officially designated 6242Y, and the 3-core plus earth is 6243Y.
The T&E with twin red conductors doesn't seem to be used that widely. It's available only in the smaller gauges for lighting switch drops, but most of the time the regular red/black is used (Regs. require the black to be taped or sleeved red when used as a switch return).
Paul, I've never seen that Earth + Two Reds cable before. I've seen a cable with two single Reds, used as a switch wire as you described, but it never had an Earth wire with it. Hmm, bare earth wires, are these still used in the UK?.
#137352 - 06/27/0311:33 PMRe: Wiring methods in U.K.
yeah french regulation requred a switched leg to be red or purple but in usa it is little diffrent we use red black et white( it is remarked for loop leg) and that wires i use it few time and i keep a piece with me i know few of my freinds here cant belive what european wire look like they were little suprised
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
#137353 - 06/28/0312:26 AMRe: Wiring methods in U.K.
Bjarney, I would imagine that regulation depth would be 2-3 feet, depending on where it is laid. With direct burial, as you may already know, there is a requirement to bed cables into sand, that has no stones in it, this has caused the failure of lots of U/G cables. XLPE, has become quite popular in NZ, as an alternative to PVC serving, it's cheaper and it does not degrade under sunlight. But, it is hard to work with when cold(As I have found) and can be hard to pull through conduits, as most lubes, can affect the insulation, we have to use KY jelly with our cables over here, anything else is too risky at 11-33kV, if the insulation is compromised!.
#137355 - 06/28/0305:42 AMRe: Wiring methods in U.K.
You know I've never stopped to think about whether the outer jacket on SWA is XLPE or some other type of plastic! It is difficult to work cold though.
A couple of years ago I had to install an underground feeder to a shed/workshop in January, and it was one of those rare English days when the temperature remained down at almost freezing point until well into the morning. It took ages to get that stuff where I wanted it to go, and even longer to terminate the cable into its gland at the outside end.
As long ago as 1966 the "Regs" specified a minimum depth of 18 inches, so if you read those notes you'll see that they sometimes take a step backwards.
I've never liked the idea of underground junction boxes (not for direct burial anyway -- underground in a manhole is OK).
Trumpy, Yes, our cables still have a bare earth wire (from pictures I've seen in an Australian catalog, it looks as though yours have green/yellow insulation throughout ?). However, the Regs. now require all bare earth wires to be sleeved with green/yellow insulation when exposed at junctions and outlets.
Cable with no earth conductor was widely used for lighting circuits in the past, but from 1966 onward the Regs. required an earth at all points, so twin cable with no earth was soon withdrawn from the market. Do the NZ rules allow you to run a switch drop with no ground? Even if the mounting box is metal? The argument here was that even if the fitted switch assembly was entirely plastic that an earth terminal should be provided in case somebody replaced the switch with a fancy brass one later.
Marc, There's another subtle difference in a switch loop here. In the U.S. you would normally re-identify the white wire as black and use that as the feed to the switch, with the black as the return to the lamp, yes?
In British wiring, it's normal to use the red wire as the feed; the black (normally neutral) is then re-identified red and used as the line to the light.
BJ, I never really liked the adoption of green/yellow for grounding here, and prefer the original plain green. Some of the conductor insulation and sleeving in use for ground wires these days is really more like yellow with just a thin green stripe along it. I don't like that at all -- Plain yellow is used as the standard color for our B-phase.
[This message has been edited by pauluk (edited 06-28-2003).]
#137356 - 06/28/0306:37 AMRe: Wiring methods in U.K.
A couple of years ago I had to install an underground feeder to a shed/workshop in January, and it was one of those rare English days when the temperature remained down at almost freezing point until well into the morning.
That January is the middle of the UK winter, it's the middle of our Summer. But on the subject of cable types and regarding that link, concentric cable, is what we call Neutral-Screened, you can only use the outer screening as an Earthing(or if you are really slack in your quote, a Neutral)Conductor. But, Paul, trying to bend any large diameter cable in cold conditions, has a risk all of its own, I posted a topic a while ago about installing a 300mm2 Al cable, and believe you me, the cable did not like being bent at all, this cable had XLPE insulation on it(as all cables of this size do), It wasn't the Al conductors in the cable that didn't like being bent,it was the outer and the core insulation that was moaningabout being bent, we've had XLPE cables split on us in really cold temperatures. XLPE is nothing but a s**t-bag, to try and run in cold areas. Regarding our LV cables, we have used the sheathed Earth conductor since the early 70's, I hope that our Australian folk can back me up on this!. This method(to a certain extent) cuts down on Earth-Leakage currents, through the length of the cable. Paul, over here in NZ, We are required to run an Earth continuity conductor to all points on a circuit, regardless of wether they are required or not, makes sense though, in the example that you gave, I have lost count of the times that I have sworn and cursed the Electrician that fitted the Double insulated light fitting and chopped off the Earth wire. (Again I would ask for the input of the AUS sparkies to let us know how it is over there).