Any electrical savvy people able to help? - Lighting

[TheCarMadDad]

Yep, it happened to a replacement fixture too, although I can't say whether it was the same problem as I didn't take it apart, just took it back for a refund.

It's a bit concerning when you pay 60 odd quid for what you assume to be a decent quality light.

[Smiler.]

The max case temperature for the transformer is 80°C. It appears that the wiring/terminals are in contact with the case. Usually, the type for flex cable employed has insulation/sheathing rated at 60°C or 70°C.

It looks like a poor design.

[Dr Mike Oxgreen]

TheCarMadDad said:

I too the transformer and main part of the fixture apart and found this.... doesn't look too healthy! ??

Far kinell!

I don't agree that it has been caused by contact with the hot transformer, because the scorching of the plastic has taken place inside the outer insulation (which has been cut back). The outer insulation looks relatively unharmed. Besides, you wouldn't actually expect the transformer casing to reach its specified maximum temperature (you'd hope!).

The fact that the scorching is concentrated around the points where the bare ends of the wires would be crimped into the bullet connectors suggests to me that they weren't properly crimped, with the result that there's been arcing going on and that has generated the heat to scorch the plastic insulation of the crimped connectors. My bet is that the failed crimp is the live one with the brown wires going into it, because that's the one that has melted into oblivion - the scorching on the other crimp connector is simply because the two have (stupidly) been wrapped together in the same piece of insulation.

This is always a potential problem with 12V fittings where the current is going to be larger than it would be with a 240V fitting. Any poor connection will be much more prone to overheating.

Definitely don't just take that back to the store, because they'll just bin it and nothing further will happen. I would contact Trading Standards and send your photos to B&Q head office.

Edited by Dr Mike Oxgreen on Wednesday 21st September 07:44

[Sheepshanks]

Dr Mike Oxgreen said:

This is always a potential problem with 12V fittings where the current is going to be larger than it would be with a 240V fitting. Any poor connection will be much more prone to overheating.

Saw the same thing on kitchen cabinet lights at daughter's new (to her) house. 5 x 20W 12V halogens is 8.3 amps - the wiring into the choc block they'd been wired to had just burned away.

I was a bit thrown in the OPs case as he said the new fitting only worked partially too.

[turbospud]

TheCarMadDad said:

Yep, it happened to a replacement fixture too, although I can't say whether it was the same problem as I didn't take it apart, just took it back for a refund.

It's a bit concerning when you pay 60 odd quid for what you assume to be a decent quality light.

it properly only cost $3 to import,we had a consignment of fittings from a supposedly good manufacturer, unknown to them the invoice from thier supplier was in the pallet,yes they did not even make them,$4 each to them.

unfortunatly it has been a race to the bottom on quality for quite a few years