"Spamlet" wrote in message
...

"David Robinson" wrote in message
...
Excuse my ignorance - I've never run DC cable before!

I'm installing some of these...
http://www.tlc-direct.co.uk/Products/QLCD10C.html

Various ways of grouping them are possible, using various transformers
(e.g. one 0-250W, a few 0-50W and 0-100W).

I've done some quick calcs of the required cable size, and it seems
stupidly large.

What size cable do people use in practice? How do people usually group
the lights? Big groups / small groups? Daisy chained cable or star
wired?
Also, what _type_ of cable? What core colours for after transformer?
(On site guide allows almost anything for ELV).

TIA.

David.

It's the transformer that limits you: our kitchen ceiling has two rows of
3 with two 60W transformers. That was the electrician being unnecessarily
stingy, as it is quite difficult to tell the lamps apart, and when a 30W
one got into one of the holders, the set cycled on and off with the
overheat (presumed) cut out, and I had the floor above up, before I
realised...

Thus, when I did the bathroom I allowed for some particularly light
obsessed individual being blind enough to put in a 50W lamp, and so
allowed one 100W transformer for each pair - though still only need 20W
for most purposes, but one brighter one (splash proof) over the shower to
help wake me up!

Incidentally, we have a couple of round in-cabinet lights as well. Ours
are 'brassed' and have frosted glass and take little 10W lamps. Make sure
you 'try before you buy' cos ours are rubbish: the 'metal' being so
fragile that it distorts and soon cracks the glass when you try to unscrew
it to change the 'bulb'. You end up with a handful of broken glass.

S
ps. 'TW' above may be being a bit over cautious in allowing only one lamp
per tf : so long as we've kept within the wattage limits (which means
leaving a label somewhere to tell any user the maximum you've allowed for)
we've had no failures at all in quite a few years now (sshhh!).

S