On 22 Jan 2009 at 23:13, Pete Turnbull wrote:
The IET Wiring Regulations merely require that you
can't touch a live
part with a finger (and there's a standard to define how fat a finger
is) and without the use of a tool. It doesn't mean you can't remove the
bulb without a tool, it means you can't then touch the live part without
a tool. In the case of Christmas lights the metal is somewhat recessed,
and you can't get a finger in, so it's allowed. I assume here that
we're talking about the ones that use miniature E5 (5mm ES) bulbs. Of
course even in this case, you can touch the live part with a
screwdriver, the tines of a table fork, a paperclip, etc -- but those
are defined as tools :-) Amusingly, these lights are classed as if
double-insulated, even though all the ones I've seen are not -- the
rather bizarre justification for that definition seems to be simply that
they have no earth wire!
...or the puppy can chew on it, or baby can see what the pretty bulb
tastes like...
I've never understood why Christmas tree lamps (particularly the
miniature ones) aren't mandated as line-isolated low-voltage devices.
They're still the most prevalent type in the USA.
Cheers,
Chuck