Replace transformer?

[willifixit]

I wonder if I could seek some advice please? We have 6 12V 50W halogen downlighters in our dining room, all operating from the same switch. Two of the lights have recently started to go out after about 5 minutes of operation, and then come back on a while later. They always come on with the others when first switched on. I assume that this must be a fault with the transformer because the bulbs are obviously OK, and if there was a problem with the switch I would expect all the others to be similarly affected. The lights have been in about 10 years with no previous problems.

I have located the transformer that serves the two faulty lights and the information on it is as follows:

Lytlec
Dimmable electronic transformer
LDT105
Op voltage 240v/50Hz
Output voltage 12v eff
Output power 105vA

I’ve searched the internet for a replacement but it looks like Lytlec no longer exists (or has been taken over). So my questions are:

Can anyone recommend a replacement please – I guess that it needs to be a 105vA model. Are there any makes I should avoid or try to get? I’ve seen a 12V 105VA Dimmable Electronic Transformer [105W] Robus RM105DN at http://www.directtradesupplies.co.u...lectronic-transformer-105w-robus-rm105dn.html which might fit the bill?
As this transformer shares a circuit with two others, do I need to replace all three of the transformers on the circuit please? Just worried about compatibility issues!

Thanks in advance.

Rich

 

[securespark]

Could be a faulty unit, or it could be overheating, or it could be poor contacts on the lampholders.

Are both going out at the same time?

Is there loft insulation surrounding the transformer? This could mean it will be overheating. When it does this it will trip off, cool down, then switch on again as you describe.

 

[willifixit]

Hi

Thanks for the rapid response. Both lights go out (and come back on) together, so I guess that rules out poor contacts on the lampholders. There is no insulation in the roof space - it is a flat roof and the transformer is located as far from the lamps as it will go. So I'm thinking that there may be a fault in the unit that is causing it to trip out, maybe the cold weather has got to it!

Cheers

Rich

 

[PrenticeBoyofDerry]

Sounds like the transformer is starting to fail, but as stated above could be a number of reasons.
The transformers you have linked will do, the job.
It's likely if all the transformers were installed at the same time with identical loads and usage that they will also be ready to fail.
But check the lamp holders first for burnt and brittle flex and connection to the this transformer for loose connections.
If in doubt, you could try swapping over transformers from this lighting set to one that is functioning correctly and see what results you get.

 

[willifixit]

Well I had a good look at all the connections and all seemed to be fine - no evidence of corroded, burnt or loose connections. So I stumped up less than a tenner for a new transformer and fitted it this morning. And the lights now stay on!
Thanks for your help guys.
Rich

 

[securespark]

Excellent news!