Low voltage lights

[davycc]

Hi Guys

My question is this. I have 8 low voltage dimmable down lights installed in kitchen . This morning her indoors turned the kitchen lights on and the light circuit fuse tripped. I checked what I could and rest the trip all lights in the house bar the kitchen worked. I swapped the light switch/dimmer and all but 2 of the lights worked. I didn't have much time this morning as I had to start work but I pulled the capet back in the above room and notice that when we had gas installed last week they had been working in the area around one of the failed units. Coincidence ?

Why would 2 of the units fail (bulbs checked and ok)

Any suggestions.

PS lights were fitted from below when ceiling plaster was replaced last year so not looking forward to emptying room and lifting carpet lol.[/b]

 

[swampy2]

Why would you need to lift carpet. Do the lights have individual transformers, remove blown lamp and replace. If that fails remove light fitting and swap transformer.

 

[ericmark]

It low voltage then unlikely to have transformers if however extra low voltage then likely there will be a power supply although unlikely simple transformer more likely a switch mode power supply which are often designed to fit through the lamp holes.

The rules state that anything which will require maintenance should be accessible but question is did the installers follow the rules.

For two lamps to fail at same time one would expect two lamps fed from same power supply and it has failed but first I would swap bulbs around just in case two went together.

 

[davycc]

 

[PrenticeBoyofDerry]

If it's extra low voltage, you are likely to be looking at transformer failure.
If you can remove one of the lamps (bulbs) or if you happen to know, are they voltage rated at 12V, this should be printed on the lamp.
If you do have transformers, they should be accessible from the hole made for the light fitting, but if it's easy enough to lift carpets and floorboards that is your choice!

 

[davycc]

The lights are from homebase I have looked before when changing bulbs the fitment only drops through the hole about 3-4 inchs then the cable stops so I cant get access, there is definately nothing attached to the bulb holder . I have tried new bulbs even tried them in other units to confirm they where ok. Is anyone familiar with Homebase units are they a switch mode power supply I don't think they where transformers though I wasnt really taking much notice when they where being fitted. BTW these use GU10 bulbs if thats any help.

 

[davycc]

If it's extra low voltage, you are likely to be looking at transformer failure.
If you can remove one of the lamps (bulbs) or if you happen to know, are they voltage rated at 12V, this should be printed on the lamp.
If you do have transformers, they should be accessible from the hole made for the light fitting, but if it's easy enough to lift carpets and floorboards that is your choice!

Cheers mate I'll check when I get home but I do know I've stuck my hand in through and cant feel anything like a transformer or anything else, if there are then they must be further down the cable so think Ill def have to work from above.

As for the lifting of carpet I'd rather pull my finger nails out but hey ho.

 

[PrenticeBoyofDerry]

GU10 will likely be low voltage and no transformers should be connected, which means you have a fault on the circuit, this could be on the cable or the lampholder. But you do have a couple of them working, so a number of lampholders to fail at the same time is unlikely.
Do you know how the lights are linked up? Are they in continuous link between each fitting (Daisy chain like) or are they feed from a junction box?

 

[sparkybird]

If they were fitted from below, then all connections should be accessible from below (tbh even if they wre fitted from above the same rule should be applied) .. However, I've lost count of the number of times lights have been fitted and then the new ceiling put up with no thought given on how to access junction boxes and transformers afterwards

I would drop all the light fittings and see if you can find the junction box (if you can borrow a small pair of lady arms, then you might be able to reach further into the ceiling)
good luck

SB

 

[davycc]

Lady arms lol I can hear the reply when I ask her to stick her hand into a hole in the ceiling "theres, sipers, mice, dirt" no way!"

Thanks guys will bite the bullet and lift the carpet etc tomorrow, hopefully the pair of dud ones are wired along the the same way as the boards so only one or two boards need lifting if you know what I'm trying to say.

 

[davycc]

All sorted 3ft length of cable from supply to fitting replaced. no obvious signs of damage. I even wired a lamp holder up using it and nothing. There was quite a bit of excess cable to each fitting but it was tacked (not literally) up so freed it a tad which give sufficient to access fittings from below in future.

thanks for the help and advice guys.