This is a typical modern-style light switch. The plate is just over 3 inches square:
The mounting box used for light switches is often only 5/8 in. deep. Under current regulations, the grounding conductor would have to be sleeved with green/yellow instead of plain green, and the black (switch return) wire would need to be re-identified red:
Here's a typical 2-gang "socket outlet" or receptacle, followed by our 13-amp plugs:
And this is a "fused spur unit" or "fused connection unit," commonly used to hardwire a fixed appliance to the ring. This one is feeding a small over-sink water heater:
The fuse is the same type (1 x 0.25 in. ceramic) as used in our plugs. These spur units are available with or without a switch.
[This message has been edited by pauluk (edited 07-13-2002).]
Paul, I have seen these fittings in a couple(3) of houses in NZ here. I recently re-wired a house, that had the 3" square plates and the power sockets were wired in a ring circuit, with? MK Electric double switched socket-outlets. I do remember the plasterer swearing about them, as a standard flushbox hole over here, normally measures 2"x4"max. But, Paul, one thing that I find unusual, was the use of the ceiling-looped(junction box), style of wiring, we standardly use the switch-loop method,over here, because of the need to have an Earth conductor at each light fitting and switch. However, the older ceiling-loop method, is still around here, it's a pain.
Better get our terminology straight here. I'm not certain I understand what you mean by "switch loop" and "ceiling loop."
The two most common methods here are:
1. A junction box in the attic which will take four cables. One for power in, one for power out to the next box, one to the light fixture, one down to the switch. This results in just a single twin+earth cable at the switch (no neutral in the box), and just a single twin+earth at the light fixture.
2. "Loop-in" method. The ceiling rose for the light effectively acts as the junction box as well. One T&E for power in, one T&E continuing to the next light, and one T&E down to the switch. It has the advantage of not needing extra junction boxes wired in the attic (often time-consuming and awkward!), but can be very difficult to replace the pendant fitting with some other types of fixture later.
Re: U.K. Pics: Typical residential devices#133253 09/14/0212:49 AM09/14/0212:49 AM
Paul, Sorry about my contradiction in terms. Basically what we have over here, is this: A)Ceiling-Loop method: Feeds are run between all ceiling roses on the circuit, no junction boxes are required, a red wire is taken from the live feed at the rose, down to the switch and returns to the rose, through a sleeved black wire, this is sleeved red to signify that it is live while the switch is on. This wire then feeds one side of the lamp, the other side is the circuit neutral. The only advantage of this method is that enables a two-core switch wire. B)Switch-Looped method:Live feed is fed to all switches on circuit, this is the only method that complies with our new regulations, as every lighting circuit, must have a continuous earth conductor at all points on the circuit, regardless of what type of lighting is being installed. However, Paul, the switch loop method is much safer, with the advent of more and more Handyman type people fixing light fittings, the ceiling loop method has caused a few fatalities over here
Re: U.K. Pics: Typical residential devices#133254 09/14/0207:26 AM09/14/0207:26 AM
Thanks for the clarification. I just wanted to make sure we were on the same wavelength as these terms can be interpreted differently.
Your method (A) is the method which is known as "loop-in" in England. We also use the black as the switch return to the live side of the lamp. The black in this application should be sleeved or taped red, although in most older residential wiring this was rarely done. (Compare this with the American practice where on a switch cable they use black as the return and white -- usually neutral -- as the live feed to the switch.)
If I've understood method (B) correctly, this brings live and neutral feed looped to each switch in turn, then you run a single twin+earth to the light. Correct?
That would be a perfectly acceptable method here, of course, but it's rarely used. The ceiling rose loop-in is now pretty much standard for new construction, although in many cases I prefer the older junction box method where the light fixture doesn't specifically have loop-in provision.
I'll feed the neutral through a switch box if it makes for easier wiring, although to also continue the feed to another switch, so that there would be three cables in the box, would necessitate the use of a deeper box. That's not always easy to accommodate with our solid masonry walls.
On the earthing point you made, prior to 1966 it was common for residential lighting circuits in the U.K. to be just 2-wire with no earth. The 1966 IEE Regs. added the requirement that all lighting points, including switches, be provided with an earth terminal, even if all-insulated fittings were used. (The idea being that if somebody were to replace a switch or light later, if an earth was already present they'd use it, otherwise they might be tempted to not earth a metal fitting.)
Just one point that I don't quite understand though:
Switch-Looped method:Live feed is fed to all switches on circuit, this is the only method that complies with our new regulations, as every lighting circuit, must have a continuous earth conductor at all points on the circuit, regardless of what type of lighting is being installed.
Surely the ceiling loop-in method also allows you to have an earth at all points in the circuit? The switch cable can be earthed at the ceiling fixture.
Re Loop in at switch. I am an electrical contractor in Inverness, North Scotland. Up here the standard method of wiring lighting circuits in new domestic installations is to loop at the switch ie. feed in, feed out, switch wire to light all taken to the switch position (T&E cable), neutral wires connected within the mounting box in a strip connector. This method works well here as most new construction is timber frame, or walls are strapped & lined with plasterboard enabling the use of 35mm deep boxes. You will really appreciate this system if you have to install decorative light fittings, with only 1 cable to connect & no permanent live to terminate.
Re: U.K. Pics: Typical residential devices#133256 10/05/0202:52 AM10/05/0202:52 AM
Hello David & welcome to ECN. As far as I'm aware, you're our first member from north of Hadrian's Wall!
I run into the problem you describe quite often. Somebody wants to replace a looped-in pendant fitting with a fancy new light and there is just no provision for anything other than a single twin-&-earth cable to be terminated in it, so it results in having to crawl into the attic to install a junction box. I'm sure you've also seen the usual DIY approach to such a problem where the looped live feed just gets "choc blocked" and pushed loosely into the roof space.
Interesting about the new construction in Scotland. I saw a TV show a while back which seemed to suggest that imported Scandinavian timber homes are becoming quite popular up there now.
Personally, I would like to see more timber used here; as you say wiring becomes a lot easier without running into solid (or crumbling) masonry at every turn.
Re: U.K. Pics: Typical residential devices#133257 10/05/0210:59 AM10/05/0210:59 AM
Here in Austria I've never seen the ceiling loop method. The only common way of wiring a light fixture is to run the incoming wire to a junction box in a wall, one cable or conduit with the switch loop down to the switch and one cable up to the light fixture. So the only point with more than 1 cable is the j-box. When there were no receptacles were installed these wires were usually just pulled through the box and not spliced (without any conductor left, love the 6"rule in the US), very hard to splice in anything new, usually pigtail with single strip connectors. Sometimes this setup was even just plastered in. Probably they thought: No splice-> no access needed.