led gu10 glowing.... normal?

edthedead

Hello,

I have replaced our 4 gu10 bulbs with new led one but noticed that they seem to glow very faintly when switched off, is this normal, or do I need a new switch?

DVardysShadow

It is not a total surprise to me - particularly if the light has 2 way switches. I would be investigating whether there are earth wires in the circuit cables - and whether these are connected.

evoke

It's possibly a (lack of) earth issue.

sillygoose

another possibility..

Do they keep glowing or does it fade? White LEDS are like mini fluorescents in that they bombard a phosphor layer with intense light from an ultraviolet LED - the ultraviolet energy causes the phosphor to give off white light. Its possible the phosphor is becoming saturated and acting like 'glow in the dark' paint which works in a similar way. The way to prove this would be to remove it from the fitting and see if its still glowing.

Mrs_Egg

It may also be down to the output and the quality of the LED lamp you have used.

foomanchu

If it fades away it is normal.

edthedead

I tried taking one out and the glowing stopped so I guess some power must be 'leaking' somewhere. Is it something I should be worrying about or can I just leave it?

sillygoose

Yes I would be worried, the light switch is just an ordinary on/off switch? (not electronic or dimmer etc)

I would be wanting to pull the light switch off and see whats going on. With main power OFF remove one of the cables into the switch and terminal block or tape it off then try putting the power on see if it stops it.

Other possible thing could be some capacitance - when two conductors run a long distance together carrying AC electricity a current can pass due to capacitance effect, but for mains wiring and frequency it would be tiny - but maybe enough to very weakly light up lower power LEDs. If this were the case not much you could do about it but it should be small enough not to be a hazard.

evoke

You may also have two earths with a potential difference between the two which I imagine could cause an issue like this. I'm not a qualified electrician but I had the neon light on my electric hob isolator swich continue to glow dimly when it was switched off! This was caused by a bad/no earthing connection.

edthedead

Thanks for the replies so far:money:
I will take switch off and check the connections. I have looked at the lamps this afternoon and it is only a very very dim glow, not visable in day light unless I cup my hands round the lamp.

It didn't happen with the old halagen GU10 so I guess the ammount of power flowing must be so very small that it was not enough to light the halogen bulbs?

Re The capacitance effect that sillygoose mentioned, it is a 2 gang switch, but the other switch is switched off, could that still be the cause, both wires run up the wall next to each other for approx 2-3 foot?

The lamps, for information, are Simply Led 4w ones, so high power and (i think!) good quality.

DVardysShadow

edthedead wrote: »

Thanks for the replies so far:money:
I will take switch off and check the connections. I have looked at the lamps this afternoon and it is only a very very dim glow, not visable in day light unless I cup my hands round the lamp.

It didn't happen with the old halagen GU10 so I guess the ammount of power flowing must be so very small that it was not enough to light the halogen bulbs?

Re The capacitance effect that sillygoose mentioned, it is a 2 gang switch, but the other switch is switched off, could that still be the cause, both wires run up the wall next to each other for approx 2-3 foot?

The lamps, for information, are Simply Led 4w ones, so high power and (i think!) good quality.

The fact that the light ceases when you take the bulb from its socket indicates it is capacitance. Almost the full voltage will be available to the bulb - but very little current. A 2 gang switch with a common supply will possibly enhance the effect if the other light is switched on.