Halogen ceiling light - transformer issue!

[MonteDarlo]

I am having an issue with a 20 bulb halogen ceiling light. To cut a long story short the original 210W transformer burnt out to the pint of one bit melting. I bought another of the same spec, fitted it and the light worked. All five and dandy.

However, after I changed a couple of bulbs the light completely dies on me again. I am unsure of this is still a transformer issue or if it could be something else.anyone with any help here would be doing me a huge favour.

Thanks

 

[PrenticeBoyofDerry]

Does this transformer run 20 number halogen lamps, if so what is the full load value of all the lamps?

 

[MonteDarlo]

20 x 10W halogen capsules. All from the same transformer built into the light unit itself.

 

[PrenticeBoyofDerry]

So it worked fine with some lamps not working but when full load the transformer dies? That suggests the transformer is not up to the load requirements.
I normally overate my selection of transformer load by 20% of full load.
So in your case you have a demand of 200W, I would select a transformer rated somewhere near 240W

 

[MonteDarlo]

Thanks, I was just replacing like for like, I'll try a larger transformer.

 

[Taylortwocities]

Jut make sure that the lamps you put in ARE 10W, and not a higher value...

 

[winston1]

Thanks, I was just replacing like for like, I'll try a larger transformer.

You should not have to do that. You have a fault somewhere which needs to be found. Probably a short in one of the lamp bases where you have replaced a lamp.

 

[PrenticeBoyofDerry]

You should not have to do that.

No you shouldn't but unfortunately nor should you have a transformer working on near maximum demand.

You have a fault somewhere which needs to be found. Probably a short in one of the lamp bases where you have replaced a lamp.

It is not something that can be ruled out, but surely if there was a short across a lampholder, you would expect failure without the addition of a lamp!

 

[MonteDarlo]

When I retook the lamp apart to change the transformer I noticed that a section of one the wires connecting the lamp to the transformer looked to be damaged from the burn out, I have trimmed both of these wires back to fresh and intact wire and it seems to be working fine with all lights now working.

My question now however is when I took the light apart initially and saw part of the transformer melted I immediately assumed it was the transformer. Could the wire have been the cause of the initial fault? And if so will what I have done fix this for the long term?

 

[Nozzle]

If you had a poor connection initially, it will get very hot and make the plastic go black but continue to conduct. The transformer will continue to provide the juice, but the localised heat from the poor connection will damage the transformer.

Nozzle

 

[winston1]

You should not have to do that.

No you shouldn't but unfortunately nor should you have a transformer working on near maximum demand.
[quote=

On the contrary the transformers used for halogen lights have poor regulation and if you under load them the voltage rises and shortens lamp life.

The switch mode power supplies often used these days however can be under run but the OP specifically stated he had a transformer.

 

[winston1]

If you had a poor connection initially, it will get very hot and make the plastic go black but continue to conduct. The transformer will continue to provide the juice, but the localised heat from the poor connection will damage the transformer.

Nozzle

Possibly.