Wiring

orc · Posted: Sun Dec 31, 2006 4:10 pm Post Subject: Wiring

I\\\'ve installed down lights (5x50 watt) on .5mm2 cable is this too lite should I use a heavier gauge cable?

mst · Posted: Sun Dec 31, 2006 4:27 pm Post Subject:

proberly will be alright but........

if i found that in my house i would definately change it!

i take it its not done in singles?

dingbat · Posted: Sun Dec 31, 2006 4:30 pm Post Subject:

250W / 12V = 21 amps

Rating of 0.5 sq mm flex is 3 amps (Table 4H3A in BS 7671).

I'd say 'you do the maths' but I already did it for you.

orc · Posted: Sun Dec 31, 2006 5:14 pm Post Subject: Wiring

dingbat wrote:

250W / 12V = 21 amps

Rating of 0.5 sq mm flex is 3 amps (Table 4H3A in BS 7671).

I'd say 'you do the maths' but I already did it for you.

Thanks for your reply, so quick on new years eve, I'm using 240V instead of 12V, can you respond again, I kind of think the wire is too light for 240V

orc · Posted: Sun Dec 31, 2006 5:18 pm Post Subject: Wiring

mst wrote:

proberly will be alright but........

if i found that in my house i would definately change it!

i take it its not done in singles?

Thanks for the reply, its not single cable, two core, but I think I may rewire soon. At the moment the lights only go on for five minutes at a time but could be a problem in the future if on for any length.

kevnurse · Posted: Sun Dec 31, 2006 5:19 pm Post Subject:

You have a 250W load on a 230V supply, so the current draw, when all the lamps are lit, is 250 divided by 230, which is slightly over 1 Amp. Your cable is rated at 3 Amps. Its safe.

orc · Posted: Sun Dec 31, 2006 5:25 pm Post Subject:

kevnurse wrote:

You have a 250W load on a 230V supply, so the current draw, when all the lamps are lit, is 250 divided by 230, which is slightly over 1 Amp. Your cable is rated at 3 Amps. Its safe.

Thxs

dingbat · Posted: Sun Dec 31, 2006 5:36 pm Post Subject:

Sorry about that, for some reason when I read your post I automatically inserted the words 'extra low voltage' somewhere in my head.

There are so many non-compliant issues with the use of downlighters that I always fear the worst!

orc · Posted: Mon Jan 01, 2007 12:11 pm Post Subject:

dingbat wrote:

Sorry about that, for some reason when I read your post I automatically inserted the words 'extra low voltage' somewhere in my head.

There are so many non-compliant issues with the use of downlighters that I always fear the worst!

Thanks for the help anyway, its great to get help and I likewise always fear the worst. The lights have been in operation for six months now without problem but I knew there was this question in my mind that I needed answered. Happy new year.

dingbat · Posted: Mon Jan 01, 2007 12:25 pm Post Subject:

orc wrote:

The lights have been in operation for six months now without problem but I knew there was this question in my mind that I needed answered.

There are probably a number of issues you are unaware of, not least the method of termination of conductors and enclosure thereof. That there are not more problems with electrical installations generally is more a matter of sheer luck than of good practice.

Practically anybody can connect electrical equipment so that it works; it's when it fails that the real problems can occur. I see very few DIY installs that fill me with any confidence (I see quite a few so-called professional jobs that make me shudder, too.)