In article , Charles Middleton
writes

"Martin Angove" wrote in message
...

I've just found the instruction leaflet for mine - Aurora downlighters
from Screwfix (p163, 19324). The dimensions given are 135mm height -
i.e. in total from ceiling to nearest obstacle above, and 75mm *from
spring mount* to nearest vertical obstacle. The diagram shows a lamp
almost completely enclosed in a box of these dimensions though :-)

Thinking about it what I didn't (foolishly) consider was the distance from
the fixture to the joist - its quite close. What's the heat tolerance of a
ceiling joist and how hot can these fixtures get? Has anyone known of these
units setting fire to things before - I imagine its a distinct possibility!

I'm starting to get a little concerned about the set up now - I would want
to have an fire in the void between my ground and 1st floor!


I think you are worrying unnecessarily. You would have to try quite hard
to start a fire with a LV downlighter. You certainly would not be able
to set light to a ceiling joist with one even if it was touching.

A lot of the clearance measurements are to give cooling to keep the lamp
life reasonable.

--
Tim Mitchell