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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1582657
MikeE wrote:We had this problem and found the problem was that we had little red neon lights in the light switches, put there to find them in the dark


I have this with my garden lights, since I have the neons to locate the switches in the dark. I have CFLs on the circuit and one of the CFLs flashes briefly once sufficient charge has passed to charge up the capacitor...maybe 2 or 3 times a minute.
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By T67M
FLYER Club Member  FLYER Club Member
#1582698
rikur_ wrote:I've got a couple of other lights on smart switches that won't go off completely either


It is worth noting that many of the so-called "smart" dimmers (e.g. LightwaveRF), and some "smart" switches, have a minimum load of ~20W - and as most LED lights are 9W or less, you need at least three LEDs to meet that requirement. If the minimum load isn't met, the lights will glow slightly even when they are supposed to be off.
#1582716
I leave an outside PIR operated floodlight on all night and after reading this thread noted that when it is in the standby mode, all of the little LEDs in the cluster are just visibly on. The cable to it is in the order of 150ft from the fuse panel.
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1582927
Paul_Sengupta wrote:
MikeE wrote:We had this problem and found the problem was that we had little red neon lights in the light switches, put there to find them in the dark


I have this with my garden lights, since I have the neons to locate the switches in the dark. I have CFLs on the circuit and one of the CFLs flashes briefly once sufficient charge has passed to charge up the capacitor...maybe 2 or 3 times a minute.


Funny how internet adverts work. Having typed this, I got an advert for this just now on facebook:

https://www.amazon.co.uk/Masterplug-1-Gang-Weatherproof-Outdoor-Switched/dp/B004R276KO
By PaulB
#1582934
... and if we click on that link we'll all get similar adverts! :-)
#1583290
I have LED lights with dozens of feet of 3+E cable complete with intermediate switching and no problems. All switches are standard mechanical types.

Would it be possible to disconnect the existing 3+E cable and 'jury-rig' another 3+E cable between the switches?

Have you tried changing the switches? Or simulating the switches with Wago (or similar) connectors

There's leakage somewhere - capacitive or otherwise.
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#1583425
Sudden thought: Are you certain that it's the live feed being switched and not the neutral? A wiring error on the switches?

I can imagine the neutral being switched, leaving the lights with the live on one terminal. A little bit of earth leakage (not enough to trip the RCD) in the lights might make them glow faintly.

Just an idea.
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By rikur_
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#1586827
Bert Presley wrote:Would it be possible to disconnect the existing 3+E cable and 'jury-rig' another 3+E cable between the switches?


Finally got around to a bit more investigation on this yesterday.

I took a 10m drum of 3C+E and uncoiled it.
Connected one core to live, one to neutral and one disconnected.
At the far end:
- Live to Neutral 243v
- Neutral to disconnected 53v

Then connected a standard GU10 LED bulb across the floating - neutral, and it did nothing. Then tried with one of the dimable G9 LED bulbs like in use in the house, and it lit dimly. Not sure if the fact that it's a dimable bulb is the significant factor here.

Confirms what others said earlier in this thread, but I was curious to prove it for myself.
#1588349
Hmmm. It certainly looks like capacitive or maybe very high resistive coupling - as you have surmised. The measured 53V - disconnected to neutral - was presumably measured with a modern high-impedance meter. An Avo might have said zero.

On the face of it, it looks like the dimmable G9s have a high impedance compared with the GU10s. Or, perhaps, the mains has some spikes on it which are activating the G9's dimming circuit. Weird.
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By rikur_
FLYER Club Member  FLYER Club Member
#1588360
@Bert Presley The boffins on the IET forum seem to go with the capacitive coupling explanation. Apparently about 1 nanofarad per 10m length in 2 core, which gives about 0.1mA displacement current .... or one 300th of their normal peak load. In the 3C+E configuration there is greater capacitive coupling as in certain switch settings two cores are live. Assuming that doubles the coupling then that's a 150th of full load current .... add in a few more metres of cable and the lights are 1% on.