On 22/01/2009 18:50, Tony Duell wrote:
I beleive that Christmas lights are one of the
few (if not the only)
single-insulated non-earthed device that can be sold in the UK.
[ ... ]
I also wonder how the light bulb sockets (both
the BC (Baynoet Cap) ones
used in the UK and the ES ones used elsewhere are approved. With the bulb
removed (which can be done without the use of a tool), there are exposed
livel parts.
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
I have pictures of the 'Standard Test FInger' (a jointeed metal thing)
used to test for this...
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,
I was thining of the dull-size BC and ES lampholders used for mains
bulbs (and thus with mains applied to the contacts). You can remove the
bulb without a tool and you can most certainly then touch live parts
with any normal-sized human finger.
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
Are they? I understood the normal appliances were 'Class 1' if they had
an earth wire and 'Class 2' if double-insulated. And that 'Class 0' was
single-insulated, but no earth, and about the only class 0 devices that
could still be sold were decorative lights.
-tony