2 Gang 2 Way Switch with LED spotlights

[aryl]

Hi,

I am replacing my standard hanging light in the landing with 240v spotlights using GU10 LEDs rather than the normal GU10 Halogen.

I have one switch downstairs in the entrance hall and the other one upstairs in the landing.

My problem is that when you switch the lights off the LEDs have a faint light (i.e. not 100% OFF) and when you switch the lights on the LEDs lights up to the normal brightness (i.e. 100% ON).

It is all wired up and double checked (actually triple checked) according to this wiring scheme,

If I replace the LED with Halogen bulb they remain off when lights are switched off.


I also disconnected the cable to the downstairs switch and replaced the upstairs with a 1 Way switch and that works perfect when using the LED bulbs i.e. 100% OFF and 100% ON.


I am running out of ideas here so any help would be appreciated!

Thanks!

 

[ColJack]

a photo of the actual wiring of the switches and light itself would be more useful than a picture of the instructions for 2 way lighting that most of us already know..

 

[maltaron]

LED lamps do glow after switching off. They will eventually go out. I think that they have a capacitor in them which takes a little time to discharge. Its not a problem with your wiring.

 

[electronicsuk]

It is far more likely that you have capacitive coupling between your live and switched live wires. It's a very common problem, as you have found, in two way circuits, due to the use of 3C+E cable in which line conductors are run parallel to each other with no CPC or neutral inbetween.

You can solve the problem by using one normal halogen lamp in the circuit to add some extra load, which should prevent enough voltage being present to light the LED lamps. However, there will still be a small current flow into the lamps even when the switches are off, just not enough to light a filament lamp. Unless it actually bothers you then there's no need to worry about it.

 

[aryl]

Thanks for the quick replies!

I have added some additional photos of the wiring in the switches, Spotlight, junction box etc.

THe light does not go out after a while so it is not down to a capacitor in the LED.

Sounds more like there is a capacitive coupling but I do not want to use any Halogen lights. Is there any other solution?

 

[SparkyFromTheValley]

if u really want to sort it without rewiring it all, use 12v lights.

 

[electronicsuk]

Sounds more like there is a capacitive coupling but I do not want to use any Halogen lights. Is there any other solution?

There are a few options. You can do as already suggested and use MR16 downlights with 12v transformers, although as you already have GU10 fittings and lamps I doubt this is something you'd be interested in.

Another option is to mount a small pygmy lamp somewhere out the way (in the loft, if you want) and run it in parallel with the LED lamps. This should solve the problem, but it does necessitate adding extra load to the circuit that wont be providing you with any useful light.

Thirdly and finally, run a new length of T+E between the switches and use this for your strappers on L1/L2. The CPC/earth conductor should prevent any coupling between L1 and L2 due to being connected back to earth. You can use one of the existing cores for common.

 

[ColJack]

Downstairs Switch

• aryl
• 26 Mar 2009
• 1

Upstairs Switch

• aryl
• 26 Mar 2009
• 1

Junction box in loft

• aryl
• 26 Mar 2009
• 1

bottom right hand cable in the JB picture goes where?


sure you got the right black wire as the neutral??

if you have the wrong black wire as the neutral you are getting "feedback" from another light when switched off..

do any of the other lights seem dimmer when the LED's are switched off, or so they work properly when the LED's are switched on?

 

[electronicsuk]

Also, why does the T+E exiting at bottom right of the JB not seem to have the CPC connected? If it's a switch drop (although from that wiring it appears not to be) then I'm not suprised you're having problems. Even if this turns out to have nothing to do with it, all CPCs should be sheathed and connected to earth.

 

[ColJack]

well spotted that man.. I missed that...

 

[aryl]

Bottom right hand cable in the JB picture goes to a loft light with a switch. Agree that bit is not the best installation, should get a proper light and cable while I am at it. I did not have it connected initially so the problem was there before.

On the bottom left hand side there are 2 cables, one goes two the landing switch and the other is the Live and Neutral. I have checked them with the multimeter so I have not mixed them up.
All the grey cables on top are going to the spotlights in a star congiguration rather then serial as it woud just be a waste a cabling.

I have checked all the lights and if they change when switching the LEDs on/off but no changes.

 

[Steve]

Its capacitive coupling. Simple as.

Its the same phenomenon that causes CFLs to flicker on 2-way circuits when turned off.

The energy required to light LEDs is very small, therefore the small amount of charge on the switch runs is enough to light them dimly. It takes a lot of energy to light a 60w bulb.

The bottom right cable appears to be 2 core flex.

 

[ColJack]

I'd double check the switch wires are the right ones, and make sure the loft light works with the LED's switched on and off..