Downlighters in loft, and loft insulation

[NeilF]

OK, we have 6 GU10 LED downlighters and 2 MR16 downlighters in the loft now over our bedroom. The electrician simply recommended leaving the insulation around these light pulled back.

When I suggested thermal caps ( http://www.tlc-direct.co.uk/Products/TLALC724.html ) they said these cause more problems than they're worth due to overheating units.

I'm interested what anyone else has done about this? To me this seems a bit slap-dash!?



I'm tempted to get some of those caps, and:-
1) Create a few holes in the top of them for ventilation, and then insulate upto/around them, but not over them.
2) With a couple of the lights, we need to board over them (for loft access) so I'll cut the cap down to the appropriate height to allow the boarding to fit over, and again, simple put the insulation upto/around it.


Any other opinions/advice?

 

[Abraxaz1]

you can use wood to create channels for the cable to run, this allows the user to place insulation over a lot more of the area.

The spark is correct, running insulation over the cable will cause the temperature on the insulation cable to rise. Most cable is only rated for 70 degrees but the stuff is 24v - 50vdc so the insulation is allot thinner hence the temperature issue

 

[NeilF]

We've not even discussed the cables... Just the insulation around/over the actual lights themselves!

 

[HardwareGeek]

The anal answer would be to refer to the manufacturer instructions, do they specify that this model of down light is suitable to be covered or not? some are some are not.

Most likely covering unsuitable fittings would just shorten bulb life, damage bulbs, burn out the connections or melt the cable, small chance of fire.

 

[HardwareGeek]

We've not even discussed the cables... Just the insulation around/over the actual lights themselves!

In the regs basically the rule of thumb is if a cable passes though 500mm of more of insulation then you derate the current carrying capacity to 50%

but in practice the cable under insulation is fine, what causes the problem is the heat from the bulb not general heat of the cable carrying the current

Generally what happens is the wires in the fitting and the cable for upto say 1ft around the light burn / melt from the heat build up, then you call a spark when the lights start tripping

 

[NeilF]

The anal answer would be to refer to the manufacturer instructions, do they specify that this model of down light is suitable to be covered or not? some are some are not.

Most likely covering unsuitable fittings would just shorten bulb life, damage bulbs, burn out the connections or melt the cable, small chance of fire.

Well, I think I'll introduce the thermal caps I mentioned in the OP, if only to keep the surrounding insulation a safe distance away from the lights. I will make a few holes in the top of them to prevent heat build up, and will not put insulation over them.