Voltage at light fitting that is turned off

[BillyTheSparks]

Hello,

I need some advice, I have wired and fitted 2x down lights with 7w Kosnic LED lamps. These are switched from 3 positions. They are on a circuit suppling 13 other down lights all with LED lamps. (All the wiring is new as it's a renovated house, which I've wired).

Now testing the conductors of the cables with the megger all tests are fine and clear. When the circuit is energised the lights work as they should (I have done this sort of thing before!)

When the light switch is in the off position the lights go off, but then 1 down light starts to flash intermittently.

I have tested at the light fittings and I'm getting 74v with the switch in the off position???!!!???

Can anyone help me with this little set-up? I have been tugging my hair out today trying to figure it out!

It's not a loose neutral, as all neutrals are connected with Wago's (Helacons). And I have taken the light fittings out of the circuit.

I have also had all the switches off and connected the wires together with Wago's but still getting the same voltage.

I'm starting to think I'm going mad, but I know that happened along time ago!

Could it be induced voltage in the 3core between the switches? I have turned off all circuits apart from this one so I know that it's not coming from anywhere else.

If it is induced voltage can I loose it somewhere using something? I have been thinking of ferrite magnets? But I don't know that much about them.

Could it also be the lamps? Has anyone had anything sililar happen to them?

Sorry to go on but it helps to get it down on the screen.

Cheer
Billy

 

[Rauer]

I'm not certain but I seem to recall someone on here saying the lamps have capacitors in them , so could be discharge?

I have led plinth lights and the misses sees them flash occasionally

 

[telectrix]

induced voltage. this can be improved by fitting a snubber ( or more than 1). across the sw L and N on each group of LEDs.

 

[simpson93]

induced voltage. this can be improved by fitting a snubber ( or more than 1). across the sw L and N on each group of LEDs.

would you get 74 volt tho from induced voltage alone?

 

[BillyTheSparks]

I'm not certain but I seem to recall someone on here saying the lamps have capacitors in them , so could be discharge?

I have led plinth lights and the misses sees them flash occasionally

I also thought it could be a discharge, but not all of the down lights do this. Could it be because there is only two on this sw line?

Could it be the lamps? they're not the cheepest, but I have had problems with the Kosnic 5w dimmable range.

 

[simpson93]

I also thought it could be a discharge, but not all of the down lights do this. Could it be because there is only two on this sw line?

Could it be the lamps? they're not the cheepest, but I have had problems with the Kosnic 5w dimmable range.

dont think its because you have two, have you checked the other fitting for any voltage?

 

[BillyTheSparks]

induced voltage. this can be improved by fitting a snubber ( or more than 1). across the sw L and N on each group of LEDs.

Hi, What is a snubber and where do I get them from?

 

[BillyTheSparks]

dont think its because you have two, have you checked the other fitting for any voltage?

Not yet. I didn't bother as I was so caught up with it.
But i'm also getting a Voltage at the terminal of the sw without the sw live connected there.

 

[Farmelectrics]

When we say snubber we mean a resistor don't we but what size would we get for a lighting circut

 

[simpson93]

maybe a stupid question, have you checked for voltage with the circuit switched off?

 

[telectrix]

Hi, What is a snubber and where do I get them from?

it's a resistor and/or a capacitor combination. there are various ones. it has been suggested that a 330K resistor across L and N terminals in the one of the fittings might do the trick. a bit of trial and error involved. have you tried measuring the voltage with an analogue meter. ?

 

[BillyTheSparks]

maybe a stupid question, have you checked for voltage with the circuit switched off?

Yep, no voltage with the MCB off.

 

[nickblake]

i always used 1 meg seamed to do the trick

 

[Farmelectrics]

Tel when you say trail and error were did you get the 330k value from then wouldn't no what value to get myself

 

[BillyTheSparks]

have you tried measuring the voltage with an analogue meter. ?

Nope, whats one of those?? Haha! I only have digital testers

 

[telectrix]

well, nick's just suggested 1 Meg. that's the trial and error part. try 1 Meg., and if it's no improvement, try a lower value. ( not too low, of course ). the combined R/C snubbers may well give a better result.

 

[BillyTheSparks]

ok so where do I get these things?

 

[topquark]

Clamp the cable and see what current has been induced, then you can work out the value. Discrete components from RS/Farnell/Maplins.

 

[BillyTheSparks]

Clamp the cable and see what current has been induced, then you can work out the value. Discrete components from RS/Farnell/Maplins.

Will try that when I'm next on site, Thank you.

 

[Knobhead]

This is repeat of a previous thread.
You could try either of these methods, no danger of resistors overheating.
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