Glad to see this has provoked a lively discussion!
Sparky,
Sorry if I missed the irony first time -- I must have been tired that night. I too noticed that the '02 NEC now has everything in English & metric units. When the British IEE decided to change over with the 1970 edition they just dropped English measurements completely in favor of metric. Not a good decision in my opinion.
CT,
I hadn't thought about the colors where Romex is used on a 240V (no neutral) circuit like the water heater, but I take the point. I was looking at the small appliance branch (120V only, not multiwire) shown in red and white.
The point several of you have made about the depth (or lack thereof) of British boxes is one of my major grumbles about our fittings. Wiring space is very cramped in many cases, especially at something like a double receptacle where a spur cable has been added. I like to use deeper boxes wherever I can, but it's not always easy when dealing with the masonry walls which are so common here.
Sven,
I thought these were regularly used in the theatre industry and also for some residential lighting circuits-switched sockets
The 2A types used to be found quite regularly for switched lighting outlets in some homes, but as David has pointed out, the practice is almost extinct these days.
You're right about BS546 plugs in theatre applications though. Aside from any desire to make the plugs non-interchangeable, there's a much more practical reason for using them.
Regular 13A plugs all contain a fuse. It's not uncommon for a suspended spotlight to be fed through half a dozen or more different extensions and connectors from the control booth. If a lamp burns out, it's enough trouble to get the ladders out and climb up to change the bulb. If the bulb shorts out (or some other fault blows a fuse) you don't want to have to trace all the extensions back to find which of the many fuses opened the circuit. (Yes, I've been involved with the lighting & sound for amateur dramatics!)
[This message has been edited by pauluk (edited 10-29-2002).]