Mercury lamps!

28 Oct 2003
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United Kingdom
I am about to install one 80watt mercury lamp outside on its own circuit. Its fed by a 10m length of swa and Teed off to a 10m length of 2.5mm swa. The T is so i can add another light later on.

My question is as this is a dedicated circuit, what size breaker should i use? i know the lamp in only 80w but i don't know if it was high start up current or anything I'm overlooking.

for those curious the cable run looks like this:

CU-----4mm SWA--------Junction box for optional light
2.5mm SWA
Junction box for 80w mercury lamp

The lamps shall be connected the the junction boxes via artic blue cable, and appropiate glands used.....

edit: my pic doesn't work too well! the 2.5mm SWA should be joining the 4mm swa. not comming straight from the CU
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just use a 6A type B as you would on a normal lighting cuircuit

your cable rating is plenty high enough for it and its giving plenty of room for inrush currents
Why use mercury, seems a strange choice, most people prefer Metal Halide lamps for the same purpose, from what I'd heard they're becoming less popular.

Of course, who needs to bother with a lamp fitting when you can just have a microwave do the job?

Some people have way too much time on their hands, and way too many lamps and microwaves to ruin...
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