transfomer junction box

[murdock]

what are your thoughts on transfomers in the roof space?

junction box or open?

[Sparks]

Open terminals - ventilated box
Shrouded terminals - acceptable open.

[AndyD]

How about open terminals but insulation taped closed? I always insist they're screwed to a joist or baton. I don't allow them loose on the ceiling board.

[Sparks]

Insulation tape melts and yes, they must be secured.

[bergie]

How about open terminals but insulation taped closed? I always insist they're screwed to a joist or baton. I don't allow them loose on the ceiling board.

andy ,are you talking about the 50 va,s as well . most of the time i connect it on the ladder and then push them through the hole and for maintenance just pull it out. keeping in mind the distance the transformer must be from the lamp.

[AndyD]

Admittedly it's not always practical but if the transformer has screw fixing slots and especially if the ceiling has insulation we require the transformers to be fixed. Ive come across a couple of installations with loose roof insulation that's been pumped in and the transformers have gone molten and caught fire. The transformers were installed after the insulation was pumped in but because of their weight they bury themselves over time.

This is a notorious area of contention with little consensus between individual electricians. There was a relevant thread here not so long ago and it all boiled down to the use of the words 'should' and 'shall' in the 0142 regs.

PVC/vinyl Insulation tape is rated to +70C so it ought to be suitable for insulation of transformer terminals. If the temp is higher than that the lighting should be cabled in silicone cable, not PVC.

[ColinK]

Ok but obviously your plastic 50w downlight transformers "new type" dont apply to heat at all???