Problem with Halogen Cable Lighting

[RichardClarke]

Within my kitchen I had installed 2 sets of Halogen Cable Lights, each containing 5 halogen lights each light is 50 watt. At the end of each kit is a 12v transformer which is connected to the mains. These lights were installed approximately 2 years ago. As readers will be aware there are 2 pieces of wire that run from the transformer to each end of the cable lights to form a circuit. Here lies the problem...recently one of the cable lights has stopped working and on further inspection the problem is a break in the circuit namely one of the wires from the transformer appears to have burnt out and detached itself from the cable lights. The other set of lights is still working but the same wire for that set appears to be black in colour and is no doubt going the same way.

If anyone can help, I'd like to know if this is a common problem with these sort of lights or is it a manufacturers problem or a problem caused by the installation. In order to mend the lights I assume I need some sort of insulated wire to replace the burnt out one...any ideas what sort of wire I use ?

Thanks in anticipation.

 

[malcolmsanford]

First I would check and see if that 5x50watt lamps is above the manufacters recommendation. Not knowing every light fitting ever made, but 250watt of halogen lights seems excessive. You may find, and I could be totally wrong, that it may be overloaded.

Saying that if it is recommended that you can use 50watt lamps then it would seem that like most things in todays world your fittings may have built in destruction. I assume they came with a years warrenty and after that it's just how long they will last. If your so inclined you could contact the company telling them of the situation and see if they even respond, as they are most likley made in China .........good luck

Personally I would not try and repair them unless they are really expensive. Like most older things once you repair it somewhere, something else breaks ie the Transformer.

If you are going down the repair route then this might be the best cable to use.

Heat Proof Cable

Thougfh this is not cheap or easily available. Also check your lamp holders. Halogen lamp holders have springs insdie to accept the lamp and these can wear and give you a loose connection that can lead to over heating

 

[RichardClarke]

Thanks for the advice...after what youve said I checked the bulbs only to find they were 20 Watt and not 50 !! I took the burnt/fused wires from between the transformer and light cable line and went to a local electrical supplier. They suggested replacing the transformer is it was clear signs of "overloading" and there was little point replacing the connecting wires as it would just happen again or alternatively change the whole light system which at a cost of £120 each im reluctant to do. Whilst taking the transformer off I noticed that the earth wire was not connected, now I'm not an electrician but even I know this is dangerous but could this be the potential cause of the problem with the overloading and burning of the connecting wires ???

If I replace the transformer any ideas for a compatable model, the specification on the current tranformer says 230v-240v-50Hz and 12v-Max105VA there is a little diagram of a cable showing 150c what does this mean??

 

[telectrix]

1.the transformers are Class 2 and do not need earthing. the earth , or cpc, should not be connected, just as long as it is continuous through all the 230v cables. 2. 105VA transformer will just cope with 5 20watt halogens, theoretically, but experience has shown that it is far better to use 1 tranny per fitting. 60VA trannies for this are only about £4-£5 each, so £25 for new trannies, 1.0mm or 1.5mm for the 230v. heat resistant flex for each lamp. sorted.

 

[spud1]

Any good wholesaler should be able to point you in direction of replacement trans. 150C maybe temp rating of cable in celcuis? Tell me is it clear insulated with silver coloured braided wire ? If so quite common wire lighting wire. Have got replacement wire in past from wholesaler. 105VA means no more than 5 x 20W lamps fed from that trans. (i.e 5x20= 100W or VA put basically) so dont replace lamps with 50W by accident. If overheated perhaps consider loose connections also as well as overloading of transformer.

Spud

 

[Guest123]

Ok so the rating of your transformer is 105VA which basically equates to 105W. The loading on the transformer is 5 x 20W = 100W so the transformer is working at pretty much it's capacity whenever the lights are on.

I would suggest you replace the transformers for larger, a minimum of 200 - 250 VA as they should never be worked at or near their capacity for the very reason you have encountered.

As for the earth conductor, these transformers probably do not have an earth terminal on them as they are of class 2 construction so it should be terminated safely in a cable connector or seperate joint box terminal. This would have no bearing on the overloading situation.

A transformer per fitting is a far better set up IMO.

 

[telectrix]

just beat you there Lenny with an almost identical reply. bigger capacity TX or separate TX's

 

[Guest123]

just beat you there Lenny with an almost identical reply. bigger capacity TX or separate TX's

I just cant co-ordinate my fingers sometimes......

 

[telectrix]

happens to the best of us. my excuse is jack daniels, what's your's? and don't reply to "what's your's" with "I'll have a large one"

 

[RichardClarke]

Thanks for all your advice chaps but just one more thing...The transformers supplied with the kit are made of chrome and the only replacements I can find are white plastic. Assuming the transformer is not broken...could a another solution to my problem be resolved by changing all the 20w halogen bulbs to 5 or 6 watt led bulbs thus not overloading the transformer ??

 

[spud1]

LED lamps will probably not work with out appropriate driver (instead of transformer) or fit your 12V lampholders