240v mains LED spotlight flashing when switched off.

I replaced a transformer-powered halogen spotlight with a 240v LED spotlight a year ago and it has worked fine until now.

Even now, when the light switch is in the "ON" position, the light works fine. However, since this evening, when in the "OFF" position, the light has started flashing with an interval of approximately once every 3-4 seconds. I have tried a different LED bulb but the same thing happens. Also, I have done no other electrical work in the house that may have caused this.

Anyone have any idea / tips as to what the issue may be?

Thanks!

chriswml said:

I have done no other electrical work in the house that may have caused this.

Click to expand...

Does that mean

"I have done no other electrical work in the house"

or

"I have done electrical work in the house but nothing which to my mind could have caused this"

?

chriswml said:

I replaced a transformer-powered halogen spotlight with a 240v LED spotlight a year ago and it has worked fine until now.

Click to expand...

You mean you swapped an SELV lamp for an LV lamp?

And you changed the control gear?

When the switch is of capacitive coupling between Live and Switched Live allows enough energy to reach the lamp and make it flash. A well known problem with energy saving lamps. They save this very small trickle of energy until it is enough to make the lamp flash.

If this has suddenly started to happen then you should check that the earth conductor in the cable to the switch is still intact and connected to the earth conductors. With the earth in place the capacitive coupling Live to Switched Live is less effective.

Putting a capacitor across the lamp will absorb this energy and prevent the lamp flashing.

//www.diynot.com/forums/viewtopic.php?p=1378727#1378727


Capacitor 0.047uF micro Farads 250 volts AC in series with a resistor 100 ohms

Which come pre-packaged as a contact suppressor from RS Components

RS Stock No. 206-7847
Manufacturer Evox-Rifa
Manufacturers Part No. PMR209MB5470M100

There are other sources of the contact suppressors

Read more: //www.diynot.com/forums/viewtopic.php?p=1955748#1955748#ixzz1V4ZNeavD

Hi Guys.

Thanks for your responses. Sorry for the delay but I've been away since Monday.

ban-all-sheds - I have done no other work at all.

securespark - the spotlight I had in the ceiling was a low voltage GU5,3 type halogen bulb. This was attached to a transformer, which in turn was connected to the mains. I removed the transformer and connected a 240v GU10 fitting in it's place. The bulb I have used since then is a 4W GU10 LED lamp.

bernardgreen - Thanks for your suggestion and the explanation! I shall have root around in the switch and cables this weekend. Hopefully it's nothing more than a loose earth connection!

chriswml said:

Hopefully it's nothing more than a loose earth connection!

Click to expand...

Even with an intact earth system the capacitively coupled energy can be sufficient to activate the LED either as a series of flashes or a continuous dim glow.

Extending what bernardgreen has written about capacitive coupling. The flashing when the switch is in the off position can indicate that the switch is in the neutral line instead of the live. The lamp remains live when switched off, builds up a stored charge then discharges via the LED to the lamp chassis (especially an earthed chassis)

Are you sure no other wiring has been changed in the property?
Have you had a new meter fitted?
Any work done on the meter? incoming service? Anything at all?

Do you have a reliable and safe method of testing polarity?

bernardgreen said:

chriswml said:

Hopefully it's nothing more than a loose earth connection!

Click to expand...

Even with an intact earth system the capacitively coupled energy can be sufficient to activate the LED either as a series of flashes or a continuous dim glow.

Click to expand...

Thanks for the additional info.

sparkticus said:

Extending what bernardgreen has written about capacitive coupling. The flashing when the switch is in the off position can indicate that the switch is in the neutral line instead of the live. The lamp remains live when switched off, builds up a stored charge then discharges via the LED to the lamp chassis (especially an earthed chassis)

Are you sure no other wiring has been changed in the property?
Have you had a new meter fitted?
Any work done on the meter? incoming service? Anything at all?

Do you have a reliable and safe method of testing polarity?

Click to expand...

Thanks for your input sparkticus. Yes, I'm sure that no other wiring has recently been changed.

A year ago, when I changed the problem light, I also swap out five other GU5.3 LV halogens + transformers for 240v GU10 LED's on a different floor although I've had no problems with them and they continue to work fine. Apart from the light fittings, which I attached to existing connectors, I didn't touch the wiring itself at all.

No, no meter work/incoming service/any work at all on the electrics since a year ago. And no, I don't have a way to test polarity.

I think I shall have to get a friendly electrician round at the weekend to give me a hand and advise me. It's one thing trying to learn to do something myself but wiring / electrics is certainly not something I want to get wrong and inadvertently make unsafe in the process .... changing a few light fittings / switches / sockets is fine but I think I should better quit whilst I'm ahead and learn from somone showing me how it's done!!

Thanks again for all your advice guys!