Led lights in bathroom still glow when isolated

[markymark2406]

I have led down lights in the bathroom ceiling which glow when they are turned off, also in circuit is a extractor fan with a permanent and switch live
Any ideas ?

 

[ericmark]

Most LED bulbs do sink a little power to get around the inductive and capacitive linking with AC in the cables, but some times it is not enough, you can fit a load capacitor or different make bulbs. I have found a problem with G9 bulbs, but not BA22d, a lot is down to room to fit capacitor or bulb, I did find some G9 bulbs that did work OK but the covers would no longer fit.

 

[bernardgreen]

There is capacitive coupling between Live and Switched Live in the wiring to the switch, this allows a small amount of power to bypass the switch ( when OFF ) and an LED lamp can glow on this small amount of power.

This leaked power can be absorbed by a snubber connected across the lamp

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

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

As a contact suppressor it would be fitted between Live and Switched Live at the switch BUT as a snubber it has to be fitted between Switched Live and Neutral at the lamp..

( If there is a Neutral at the switch it may be more convenient ( space wise ) to fit it in the back box of the switch )

KEMET RC Capacitor 470nF 100Ω Tolerance ±20% 250 V ac, 630 V dc 1-way Through Hole PMR209 Series
RS Stock No. 206-7869
Manufacturer Evox-Rifa
Manufacturers Part No. PMR209ME6470M100R30


There are other sources

 

[ericmark]

I got mine at CEF but it was rather on the large size, only just got it to fit in the lamp base, then the lights pulsed, then when from a small G9 bulb same size as quartz, to a massive bulb like this

not a clue where the wife got them, but the problems went. I suppose when you think about it getting all the bits inside a very small package is a problem, but can't fit the glass diffusers over the new bulb, but did cure the problem.

But as yet we don't know what bulb is fitted.

 

[leegsi]

There is capacitive coupling between Live and Switched Live in the wiring to the switch, this allows a small amount of power to bypass the switch ( when OFF ) and an LED lamp can glow on this small amount of power.

This leaked power can be absorbed by a snubber connected across the lamp

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

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

As a contact suppressor it would be fitted between Live and Switched Live at the switch BUT as a snubber it has to be fitted between Switched Live and Neutral at the lamp..

( If there is a Neutral at the switch it may be more convenient ( space wise ) to fit it in the back box of the switch )

KEMET RC Capacitor 470nF 100Ω Tolerance ±20% 250 V ac, 630 V dc 1-way Through Hole PMR209 Series
RS Stock No. 206-7869
Manufacturer Evox-Rifa
Manufacturers Part No. PMR209ME6470M100R30


There are other sources

https://uk.rs-online.com/web/p/rc-network-capacitors/2067869/

How would that be fitted in a normal light fitting?

 

[bernardgreen]

There will be a terminal block where the cable connects to the lamp. It will be either in the ceiling rose or in the lamp itself.

One lead from the snubber into the terminal with the Neutral and the other lead into the terminal with the Switched Live. If necessary put some sleeving on the leads to prevent short circuits

In the ceiling rose it would be wired liked this ( thanks to flameport for the excellent image of a ceiling rose which saved me having to draw it )