12V Down Lights Intermittently Working

[marky1]

Hi

Customer has x5 12v down lights in kitchen, each with there own transformer. 1 of them stops for approx 10/15 minutes then comes back on. I have checked all connections for tightness & transformer to ensure not wrapped in insulation yet same issue. I then replaced the transformer, lampholder & bulb but still have the same problem, connections at switch is fine, its not the last fitting on circuit.

Any ideas please? 

 

[Sharpend]

I've just had a very similar problem at one of my customers, another spark, in my absence, changed the original R80 down lights for some JCC 12v fittings, had nothing but problems with the lights coming on and going off in random order? I tested all cables, all clear, checked connections throughout, nothing, still the lights danced a merry dance. Swapped them out for some JCC 230v versions and not had a days problem since.

I can only suspect that the halolite transformers were cheap rubbish.?

 

[Steve3948]

Is there enough room for the heat generated by the lamp to dissipate in the void.

Try a transformer that can be covered with insulation, although it wont be, or try a lower wattage lamp and see if it still happens.

 

[marky1]

Ok thanks Sharpend, i will try another transformer first & go from there. If no joy then might have to look at 230v option

 

[Steve3948]

Does it still do it if you drop it out of the ceiling.

 

[marky1]

Steve 3948, although its a flat roof, id say the gap is at least 18 inches all over. The existing lights have been in over 5 years with no problems till now, i will try new transformer & lower wattage bulb & see what happens, cheers

once i swapped everything over it worked fine hanging down, but it was a few days after before the same problem occurred, i can try that to see what happens, guess this will tell me if its a heat problem above ceiling

 

[sparkytim]

Most transformers have a thermal cut-out that resets after it cools down, sounds like its overheating, usually due to being to close to lamp or not enough space for heat to disipate

 

[Robin Spark]

Marky if heat is the issue then best to convince customer to swap over to 230v leds.

Customer will recoupe installation costs in electric saved you should only need replacement gu10 lamp holders, bit of cable and lamps.

Sign up for a trade account with led hut and you'll get decent prices.

 

[Steve3948]

Philips Master LED Mr16 retro fit, works with existing LV transformer, just pop lamp in.

****Just sayin****

 

[Robin Spark]

Philips Master LED Mr16 retro fit, works with existing LV transformer, just pop lamp in.

****Just sayin****

Steve have you fitted them to 12v trannies as manufacturers instructions says best with led drivers?

 

[batty]

Are you using dichroic or alutech lamps. Dichroic gives as much heat back as goes forward. Alutech heat goes forward so not so many overheating problems with lamp holders and transformers.

 

[marky1]

thanks for your help, much appreciated

 

[Steve3948]

Steve have you fitted them to 12v trannies as manufacturers instructions says best with led drivers?

The whole selling point with them is they are retro fit, replacing existing LV halogen.

This is what Philips claim, and I fitted over 60 in one house with few issues. They have a built in driver in the back of the lamp, as shown on their web site.

I say few because we had a few rooms where they needed to be the dimmable type, we left the existing dimmers and found the lamps dimmed but not smoothly, changed the current 260W for trailing edge and not much better, then tried 400W trailing edge and they were perfect, one room with 6 and one room with 8.

The only drawback £18.45 + Vat each.

Client did not want the ceilings touched and the tranny would not come through the fitting, he was fed up with keep changing lamps.

It's been about 6 months now and still all good, he was over the moon, I cringed when I sent him the bill.

http://www.ecat.lighting.philips.com/l/lamps/led-lamps-and-systems/led-lamps/master-ledspot-lv/21636/cat/?t1=ProductList

 

[Robin Spark]

Thanks Steve for the reply, I'll keep these in mind next time I get a similar job instead of taking out the transformers.