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.
Here are some notes on
Underground Cables. 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 required an earth at all points, so twin cable with no earth was soon withdrawn from the market.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).]
