Halgen picture lights problem

[steve1978]

I have recently tried to change the bulb in a halogen picture light.

The light fitting holds 2 bulbs neither was working but when i removed 1 of the bulbs the other bulb came on. It seems with both fully functioning bulbs in the fitting nether bulb will light but as soon as i remove a bulb the other 1 comes on.

any ideas folks please

 

[riveralt]

Are you sure the light has been correctly fitted and by whom?
Does this picture light link to any other light?
Is it the same light that always works/not works?
Are the lights wired in series?
Have you changed the wiring at any stage?

 

[steve1978]

The light fitting was originally fitted by an electrician and was checked at time of fitting to be working fine

The picture light is linked to another picture light that is doing the same thing.

Both sides of the light works fine with the opposite bulb removed

sorry but i am not a sparky so cant tell you how its wired

Nothing at all has been changed but they have not worked for some time as nobody could gain access to them and everyone just thought the bulbs had blown.

 

[riveralt]

If the lights are linked then it is possible that you have a loose connection either as part of the light fitting or between the two lights themselves.

How are the lights switched?
At the back of the lights I would expect one light fitting to be either directly linked to the power supply Line, neutral and earth (with an integrated switch) or through the wall or pull switch.
The second light fitting would be linked to the L/N/E of the first light fitting.

The question will be how confident are you to isolate the circuit - verify that the circuit is dead - before you remove the light fitting and examine the cable terminations?

 

[steve1978]

i don't have a problem with isolating ect and having a look for loose wires ect as quite a competent builder.

but before i go messing with the wireing is it possible that they have put the wrong bulbs in and the unit can deal with them.

The guys who messed with them originally aint got a clue and thats why they shouted me to look at something else they had messed up.

 

[riveralt]

but before i go messing with the wireing is it possible that they have put the wrong bulbs in and the unit can deal with them.

It should show somewhere on the light fitting the type of bulb required and the rating. Alternatively on the manufacturers instructions. Picture bulbs as you describe are usually the capsule type - though they can take many forms. I take it all the bulbs are the same?

The guys who messed with them originally aint got a clue and thats why they shouted me to look at something else they had messed up.

As long as it is not the guy who wired it up in the first place.

 

[steve1978]

but would the wrong wattage bulb do that to a fitting

No the guys are cooks that messed the other job up and all they did with these light was try to put new bulbs in them.

 

[riveralt]

but would the wrong wattage bulb do that to a fitting

Yes the wrong high wattage could damage the light fitting but that would become self evident when you had a look at the cabling and the bulb connector units.
The fact that only one part of the unit works and then only when one bulb is in and the other out tends to make me feel that it is a wiring issue.
Some picture frame blubs have dedidcated live and neutral positions on the their terminal connectors and mixing them up could cause the problems you describe. But without looking at the light units in detail its difficult to guess.

 

[steve1978]

I have been back over to the place and it seems that 2 more of the same fittings are having the same problem that are on on the same wireing loom and even on a different floor. all seem to work fine with just 1 bulb in on either side of the fitting in exactly the same manner. the bulbs fitted all seem the right bulbs for the job so i took a couple of photos to see if any of you guys can spot something i am clearly missing. from what i can see the bulbs fitted look to be 12v 3w and of course the 2 pin push in type.

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• steve1978
• 20 Feb 2012
• 1

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• steve1978
• 20 Feb 2012
• 1

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• steve1978
• 20 Feb 2012
• 1

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[riveralt]

Both bulbs should be similar to this:
http://www.screwfix.com/p/osram-eco-halosta-halogen-12v-g4-capsule-7w/82035

If these bulbs are all correct then the only other option as I said earlier is that the wring is wrong - either internally (the lighting unit's wiring) or the external wiring providing the power.

Next stage is to open it up and photograph the wiring inside the unit.

Given that the problem is the same across a number of the same type of lights I would plumb for the fact that the light unit's wiring is wrong.

 

[steve1978]

Its looking like i am going to have to turn the power off and have a look inside. might be a while before i can do this as some equipment that has re start problems when shut down is also run from this supply and to be honest the bloke who labeled the fuse box up must have been drunk when he did it or had dyslexia or something as nothing seems to relate to the listed item.