Downlighters go off then on

[Sanke]

Hi all
Been working on a customers shower this morning The bathroom is lit by downlighters in the ceiling Problem was two of the downlighters stopped working & then after a few minutes relit. This continued for the hour that I was there The customer assured me that this was usual & she had been advised by the "electrician" that the transformers were overheating/recooling , also another light in the bathroom didn't even light!
Was the electricians explanation feasible ? If so, safe to leave ? How should it be repaired ?
Cheers
Steve

 

[bugsy]

Yes he is right , but the install's wrong. the transformers are not matched to the lamps,
Either change the lamps to a lower wattage 35w or 20w or replace the transformers with the correct v/a rating

 

[cbw]

Seconded!

 

[Sanke]

Hi bugsy
Understand what you say but why does it only affect two of the lights ? Assuming that they are all the same ? Or would I be right in assuming that perhaps they have changed these two bulbs at some stage ? The one that doesnt light, could this be a loose connection ?

 

[bugsy]

They have either changed two lamps or one transformer feeds two lamps

 

[Sav]

Hi,
I had a similar problem and upon inspection, found that the one transformer was powering the 2 downlights.
Just check the rating (wattage) of the transformer and see if it is powering the 2 downlights and what rating they are.

If yes to the above, use one transformer per light ( its the best way anyway).

Hope this helps,
Sav

 

[cbw]

Are they low voltage or GU10?

Could be blown bulbs, transformer or poor wiring on the dead one?

 

[Sanke]

Looks like I've got to get some floor boards up then Just so that i am clear we are saying that best way should be one transformer= one light = same wattage i.e 25w trans 25w bulb Second way one transformer = two bulbs i.e. 50w trans, 2 x 25w bulb At no stage should the bulb be higher than the transformer These were put in ten years ago Should they have intumescent hoods ?

 

[cbw]

you should be able to pull them down without having to get floorboards up!

 

[bugsy]

You should be able to remove D/L and pull trannies through cut out, yes match trannie to lamp, bet they hav'nt got fire hoods

 

[Sav]

Hi again,
Normally the transformers are 50 or 60w ratings. Its best to use at least 70% of the rating of the transformer. e.g 50w transformer = 35w minimum rated downlight. If you used 20w on a 50w transforme, you could lessen the life of the transformer and/or lamp.

Also, could you not pull the fittings down to have a look at the wiring instead of lifting floorboards up ??
Usually, you will find most connections if you pull the fitting down ( Isolate circuit first though ok )

Sav

Sav

 

[Sanke]

Didnt think of coming down but that would be easier

 

[Johno]

before you do anything drastic just check the wattage of the bulbs, because the tranny is probably 60va, so if the 2 bulbs add up to more than that change for 20w

 

[cbw]

ease them one side at a time, then when you have enough down compress the springs as they are prone to taking the edge off the cut out....Gently, gently...

 

[SirKit Breaker]

Bin the 12v crap complete with the trannys and fit IP rated 240v GU10's.