Ceiling downlights problem!

[Geldard]

Hi all. We have ceiling downlights in the kitchen. There are 7 lights, each with their own individual transformer. Now, 2 lights work together, and the rest don't. The light switch has 3 switches and a dimmer slider switch. Now the lights are wired to a normal switch but also look like they go through the dimmer at the back. One switch operates separate led lights for
Something else and one switch isn't used. All the bulbs are fine. What could be the problem? Help would be greatly appreciated!

 

[PrenticeBoyofDerry]

Did these lights ever work?
Did the ones that don't work, fail at the same time or one at a time?
Possible faults:
loose connections between fittings
transformers have died
lamps blown
Do you have any test equipment, such as a multimeter?

 

[Geldard]

We have moved in. So not sure when they stopped working. Would the other five transformers fail together? Bulbs are fine. I do have a multimeter. Is there a chance that the dimmer has failed?

 

[LooPrEvil]

Are the bulbs the correct wattage for the units?

 

[PrenticeBoyofDerry]

does the dimmer work the two lights that are working?
It would not be unusual for transformers having the same usage time to start failing around the same time.
The other two could also be on the way out.
But they might have been replaced for new at different times, so can't really say for sure.
You need to test for voltage at the supply side and the load side of the transformer, if the supply side is live and load side is dead your trany's are the problem.
If no volatge at supply side, problem further up stream likely to be loose or damaged connections.
If live at both supply and load side, check connections at the fittings and the lamps.
Also what rating is the dimmer and what load in watts are the lamps(bulbs)

 

[Geldard]

Ok, checked the bulbs, they are 12v 50w. Same as what the bulb holders say to use. All transformers are same. The dimmer makes no change to the 2 working lights. On the back of the light switch, the wires link from the switch thy operates the working lights to the dimmer, then back out. Could it be that the dimmer has failed and the two working lights are working off the switch?

 

[PrenticeBoyofDerry]

If the other lights are are also connected to the switches they should be able to operate the same.
You can test across the dimmer for voltage, at com and L2 if a voltage is present the dimmer is working.
You could also disconnect the dimmer and use a normal switch for the time being, note down the connections first, see they work of a standard two way switch, if they do it's a dimmer problem.
but if your other lights are working and connected to the same switches, the problem is not the dimmer but the dimmer must be rated for the load, you have possibly 7x50w=350w, so your dimmer must be rated at 400w or higher.

 

[Geldard]

Ok, will give it a go tomorrow. I've got a funny feeling that the 2 working lights are on a separate supply line?

 

[PrenticeBoyofDerry]

Ok, will give it a go tomorrow. I've got a funny feeling that the 2 working lights are on a separate supply line?

Well lets prove this funny feeling by some testing!

 

[Geldard]

Ok, so I removed the wires from the dimmer and used the spare switch. Now all but 2 work which are next to each other. Is it normal that te lights would be wired separately in 2's? I've proved that the cowboy has done this with the original working pair. Just wondering that the 2 that aren't working are wired separately and I need to find the wire???

 

[PrenticeBoyofDerry]

So we have now gone from having only two working out of seven to five working our of seven.

Is it normal that te lights would be wired separately in 2's?

Not what I would call normal but people have strange ideas and do odd things!

Do you know how to do a continuity test.
Also it will help if you can test for voltage, at the two lights that are not working.
Supply and load side of the transformers.