Spotlight Transformer Keeps Failing

[lms78]

Hi,

I have very little experience of working with electrics, but am keen to do basic jobs myself in order to teach myself something and to avoid paying an electrician for jobs I really should be able to do myself. As such, I apologise in advance for what is probably a very badly explained basic question.

I have 13 50w halogen spotlights in my kitchen which run off 2 dimmer switches. Each light is connected to its own transformer before the mains. In the 6 years they have been in place I have needed to change the transformer in 2 of the lights. One of these lights however is on about its 4th transformer and despite having changed it in the last 2 months, it looks like it has gone again as there is no current coming through. (I'm not sure if the light fittings were put in incorrectly, but pulling them down seems harder than it should be and always results in pulling down some of the surrounding plasterboard, which then needs filling, hence changing this regularly is getting annoying).

Anyway, given that the transformer in this light is regularly failing I am concerned there may be an underlying problem.

The first time it failed, it was obvious by looking at it that it had failed (there were burn marks). Since then the there is no visual evidence, but replacing has always fixed the issue.

The transformers I currently use are from Tool Station (dais, DA-E60, 20-60W / VA Dimmable Electronic Transformer) Product Number 55497. I have used these transformers in my bathroom (only difference there being there are only 4 lights controlled by a single switch and they are not on a dimmer) and they have worked fine. Also the first time I changed the transformer I used a different brand (but can't remember which one).

In short, I suppose I have the following questions:

What makes a transformer fail?

Should I try using a different better transformer? If so please can you recommend one?

Is there any chance that I am using the wrong type of transformer? (or would it simply not work from the outset if that were the case?)

Any other advice / suggestions would be gratefully received.

Thanks to anyone who has read this far, and apologies again for my obvious lack of knowledge on this subject!

Lee

 

[PrenticeBoyofDerry]

What condition are the lamp holders in for the lamps(bulbs)?
The transformers seem to be okay rated, if only operating one lamp.
Also just to make sure everything specs up, what ratings are the dimmer switches.

 

[333rocky333]

dimmer needs to be compatible with the transformers

 

[lms78]

Thanks to you both for your replies.

Regarding the lamp holders, I regularly have to change these on all of the lights as the wire nearest to the bit where you clip the lamp into burns away. I have to do this on all of the lights. Sometimes this seems to coincide with the lamp needing replacing, sometimes this happens causing the bulb to go out when the lamp still works. I was initially alarmed by this, but when I spoke to the guy in my local electrics shop, he seemed to think it was nothing to worry about (please feel free to let me now if you disagree). This doesn't happen all the time, but over the course of a year I would probably expect to change the holder on about half of the lights.

Even when the holders don't look bad I will try and change them before moving on to the transformers in a bid not to have to pull the whole light fitting out.

As for the dimmer. The one that controls the troublesome light is a 1-gate, 40-400W 2-way (though only wired up as a 1-way) 250V 50Hz, A 400/2 (not sure if that last bit means anything!).

As said, I have 13 lights, of which 7 are controlled by this switch. As the individual lamps are 50W, 12V, I assume that this dimmer is ok on those fronts? No idea about the Hz?

Thanks again for your help so far and for any additional advice.

Lee

 

[flameport]

Regarding the lamp holders, I regularly have to change these on all of the lights as the wire nearest to the bit where you clip the lamp into burns away.

If this is happening often, then either there is inadequate ventilation around the fitting, or you are using dichroic lamps instead of reflector types, or both.

 

[securespark]

Yeah, if the plasterboard is friable and breaking away, it is usually a sign that the area is getting hot.

Cracks in the skim coat and stiff PVC insulation are a dead give-away too.

Make doubly sure there's no insulation in the voids.

 

[333rocky333]

Dimmable doesnt always mean what it says.
The small print on the transformer or instructions usually specifies the type of dimmer that is suitable.
Ie, Leading edge, trailing edge or any type, whether it would fail the transformers im not sure.
Sometimes its just the lamp heat in the void that destroys the transformers premerturely
Have you thought about downrating the lamps to say 30 watt, this would lengthen the holder life etc as well as reduce your energy bill

 

[dhutch]

This doesn't happen all the time, but over the course of a year I would probably expect to change the holder on about half of the lights.

Doesnt sound right to me, I certainly wouldnt be entertaining it.

Bin the lot, imo.


Daniel