On Saturday 12 January 2013 18:24 snipped-for-privacy@snyder.on.ca wrote in alt.home.repair:
Like these:
If so - oh dear... I have used them in a car, in the old days. But they have no place in house wiring.
Possible slight confusion?
Ring circuits are for sockets and make a peculiar (but valid if conditions are met) claim that you can use nominal 20A rated cable for a 32A protected circuit based on there being 2 paths back to the fuse box.
Lighting, in the UK, has always bee "tree wired" - ie one or two cables leav ethe fuse/breaker and then branch all around the place until every subcircuit on a lighting circuit has been fed.
I'm curious - do you really bring 5-15 cables back to the fusebox for a single lighting circuit if you have 5-15 switched sets of lights? Or do you put a lot less lights on a single breaker?
Me: I'm running with 2 circuits (pretty normal for a UK house), both 10A (regs permit 6A, 10A and 16A - 6A is most common, and 16A is usually for commercial premises).
Curiously, if you go back to even the 1980's in England, (change was between the 15th to 16th Editions of the regs IIRC) not every point on a lighting circuit needed an earth provided *unless* the fitted was Class I (ie earthed). This of course was a bugger if a double insulated fitting was swapped out and a Class I installed.
OK - thanks for that. Pretty much the same then.