lights dim when turned off

[ngoodson1969]

Hi,

I have been called back to a job where a 3-halogen lamp fitting with 2 way switching keeps blowing a bulb. When this happens and the switch is turned off the remaining 2 lamps stay on but very dim. When the blown lamp is replaced, all is well again. I have tried everything. Isolated it from upstream lights, changed both double switches and tightened all terminals. Any ideas? Thanks.

Nick

 

[bugsy]

Are 230 or 12v luminaires, have you disconnected switch lines and applied feed diect to fitting,

 

[ngoodson1969]

Hi, I haven't tried to connect feed direct, will try that.
I think the luminaires are low voltage.

 

[bugsy]

Eliminate any possible problems with the switching first, we'll take it from there

 

[DurhamSparky]

hmmmmm... interesting..!

other than that it sounds like a fun fault to play with!! how new is the light? possibly a faulty one from the factory??

 

[ngoodson1969]

Just got back from my hols and going to look at this light again tomorrow.
Just supplying a direct feed to the lamp won't help much as the problem is created when switch is off and one lamp removed. If I remove the switch from the equation I expect that the luminaires will all go on! I reckon there's an induced voltage somewhere along the switch wire. I'm gonna create a switch external to the existing and wire it in and try it, whadya think? Also gonna try one of her other multi-lamp fittings and see if that has same problem. I HOPE it's the fitting........

Nick

 

[bugsy]

Just got back from my hols and going to look at this light again tomorrow.
Just supplying a direct feed to the lamp won't help much as the problem is created when switch is off and one lamp removed. If I remove the switch from the equation I expect that the luminaires will all go on! I reckon there's an induced voltage somewhere along the switch wire. I'm gonna create a switch external to the existing and wire it in and try it, whadya think? Also gonna try one of her other multi-lamp fittings and see if that has same problem. I HOPE it's the fitting........

Nick

It won't be

 

[ngoodson1969]

Found the cause of the dimming lights, when the smoke nearby is disconnected from the permy live then the problem goes away. Don't know why though, very strange. Any ideas????
Now I've just gotta find somewhere else to feed this smoke from.

 

[bugsy]

Is it at all possible the feed to the smoke is actually broken out of the switchline?

 

[ngoodson1969]

It was fed from the switchline, then I removed it, tried the new switch cable that I'd run and the job was fine. I then reconnected the smoke to the permanent live and the problem returned........

 

[SKY]

Hi

What is the smoke?

Thanks

 

[bugsy]

Are you sure you have a perm live from the lighting, because the fault your describing sounds as though your connecting the smoke between the switch and switch return .

 

[ngoodson1969]

It's deffo a permanent feed. Will double check tomorrow. Cheers Bugsy, you've been very helpfu.

 

[bugsy]

Hi

What is the smoke?

Thanks

Smoke detedtor

 

[pushrod]

This might or might not be related, but i recently read in a manufacturers spec that their smoke detector could not be used in a lighting circuit that had fluorescent light fittings. There was no explanation why. I assumed it must be something to do with the inductance or capacitors in the light fittings.
Do Halogen lights have anything similar??

 

[ngoodson1969]

Will have to check that, cheers.

 

[DurhamSparky]

sounds like a job i did not long ago!!

customer had new loft insulation fitted!!
installer disturbed a junction box and the live feed for intruder alarm came out!
been the nice installer he was he reinserted the red cable in to the red connector! (how ever he connected to the wrong red bit and actually connected to switch line from the landing light!

outcome!! when light on stairs is on it powers light and charges intruder alarm!
when light off it also disconnects alarm and the battery in alarm powers the light very dimly!

is your smoke doing the same!!! possibly the battery feeding the light!! i would double check the connections!!


may i also add the loft guy also mashed the screw terminals in JB!!! PRAT!!!!

 

[ngoodson1969]

I fixed the problem in the end. I just fed the smoke into a jb on the same circuit just upstream and hey presto. Very strange, it deffo wasn't the switch wire I was feeding into! One of those mysteries.
Cheers All.