Kitchen lighting problem

[wembleyford]

The lighting in my kitchen is five G9 halogen bulbs. I got sick of the cost of them as they kept burning out, and I replaced them last year with LED bulbs. Well - I replaced four of them (as the bulbs came in packs of 4). The last halogen light went out last week, and I've a new LED bulb on it's way to replace it. In the mean time, I now have 4 LED bulbs and one empty socket.

I've now noticed that when the lights are switched off, one of the LED lamps is illuminated with a very faint blue glow. This disappears as soon as I touch the metal light switch fitting (metal plate and switch). I also used one of the those halogen screwdrivers which also glowed fainting when touching the light switch.

Now, as I've been living here for five years and haven't killed myself yet, this isn't massively dangerous currently, but it is a bit concerning. I'm happy to isolate the circuit at the fusebox and take a look at hte lighting circuit and switches myself, but where should I look for faults? Is it likely to be a short circuit? Should the live/neutral wires be wired in to the switches in a particular direction, or is it agnostic? Given this is the kitchen and so it's more lilely I would have damp hands, should I replace the metal-faced light switches with all-plastic ones which, at least, will help isolate the leakage?

Thanks.

 

[bernardgreen]

this isn't massively dangerous currently,

It would apear that the metal front plate of the switch is not earthed. One fault would be that lack of Earth to the front plate.

Stray capacitive coupling between Live and Switched Live in the cable to the switch allows a small amount of current to flow to the lamp(s) when the switch is OFF. This small amount of current is often enough to cause the LED(s) to glow.

More information click HERE

If as you say touching the front plate affects the glow ( with the switch OFF ) then there is likely to be other problems with the wiring.

 

[wembleyford]

Thanks - I'll have a read of that later.

Yes, touching the metal switch plate (and the same on the backdoor switch plate also, also metal) causes the led to go out immediately. There's also a very slight buzz as if the plate is gently vibrating. Not sure if it actually is vibrating or is just a sign of me being very gently electrocuted - this is occuring when the lights are on or off..

 

[bernardgreen]

is just a sign of me being very gently electrocuted

It all most certainly is. Get it fixed as soon as possible It may not be so gentle if your other hand is in contact with something that is earthed when you touch the switch.

 

[SimonH2]

A very small 50Hz current does feel a bit like buzzing. The power supply for my laptop isn't earthed when using the "duckhead" adapter, and the result of mains filtering/capacitive coupling is such as to provide a very tiny 50Hz to the laptop body. Depending on what I'm sat on or touch, it can feel as a tinging in my palms very similar to if the laptop body were vibrating.

The fact that you get it from your light switch plates means that they are not earthed. This is DANGEROUS as a fault could make the plate live - giving you more than just a tingle.