Hi All,

I've just replaced 4 GU10 halogens with LED GU10s - 2 of which were
stocked with 15 blue LEDs. When I put them in they started to glow,
despite the power being off - just a very gentle glow that was barely
perceptible. I also installed 2 white LED replacements - these were
definitely off until switched on.

What is going on?

Cheers - Adam...

Adam-the-Kiwi wrote:
Hi All,

I've just replaced 4 GU10 halogens with LED GU10s - 2 of which were
stocked with 15 blue LEDs. When I put them in they started to glow,
despite the power being off - just a very gentle glow that was barely
perceptible. I also installed 2 white LED replacements - these were
definitely off until switched on.

What is going on?

See the hundreds of earlier threads about CFL tubes doing this.
This is just a slightly different manifestation - the bulb glows not
flashes.
The cause is that the typical house has places where live and switched
cables run adjacent to each other, often in the same cable, and the
rapid change in voltage as the AC waveform changes polarity a hundred
times a second means that it induces a current in the nearby conductor.

This isn't normally noticable with 'ordinary' light bulbs, but with CFL
tubes, they may flash, and LED ones glow slightly.
This is utterly harmless.

Ian Stirling wrote:
Adam-the-Kiwi wrote:
Hi All,

I've just replaced 4 GU10 halogens with LED GU10s - 2 of which were
stocked with 15 blue LEDs. When I put them in they started to glow,
despite the power being off - just a very gentle glow that was barely
perceptible. I also installed 2 white LED replacements - these were
definitely off until switched on.

What is going on?

This is utterly harmless.

call it night lighting


NT

Ian Stirling wrote:
Adam-the-Kiwi wrote:
Hi All,

I've just replaced 4 GU10 halogens with LED GU10s - 2 of which were
stocked with 15 blue LEDs. When I put them in they started to glow,
despite the power being off - just a very gentle glow that was barely
perceptible. I also installed 2 white LED replacements - these were
definitely off until switched on.

What is going on?

See the hundreds of earlier threads about CFL tubes doing this.
This is just a slightly different manifestation - the bulb glows not
flashes.
The cause is that the typical house has places where live and switched
cables run adjacent to each other, often in the same cable, and the
rapid change in voltage as the AC waveform changes polarity a hundred
times a second means that it induces a current in the nearby conductor.

This isn't normally noticable with 'ordinary' light bulbs, but with CFL
tubes, they may flash, and LED ones glow slightly.
This is utterly harmless.

Thanks Ian. So, essentially, it's just an induced current in the
switched cable?

Cheers - Adam...

Adam-the-Kiwi wrote:

Ian Stirling wrote:
Adam-the-Kiwi wrote:
Hi All,

I've just replaced 4 GU10 halogens with LED GU10s - 2 of which were
stocked with 15 blue LEDs. When I put them in they started to glow,
despite the power being off - just a very gentle glow that was barely
perceptible. I also installed 2 white LED replacements - these were
definitely off until switched on.

What is going on?

See the hundreds of earlier threads about CFL tubes doing this.
This is just a slightly different manifestation - the bulb glows not
flashes.
The cause is that the typical house has places where live and switched
cables run adjacent to each other, often in the same cable, and the
rapid change in voltage as the AC waveform changes polarity a hundred
times a second means that it induces a current in the nearby conductor.

This isn't normally noticable with 'ordinary' light bulbs, but with CFL
tubes, they may flash, and LED ones glow slightly.
This is utterly harmless.

Thanks Ian. So, essentially, it's just an induced current in the
switched cable?

Yes.
The design of the power supplies of these basically means that all of
the leaked current goes straight to the LED.