Dear Forum-support,
I’m a happy Velbus Customer for +3y and I call myself one of the happy early adopters and took the “good” risk to implement this solution in our new home.
So far everything is/was working perfect and every week I’m enjoying the flexible reprogramming options (christmas lights) etc.

I just have one question that I can’t explain decently with my technical background. Till now I was using old (40W-60W) bulps for lights and also played around succesfully with the first 4W power leds …
These are now replaced with the “new” generation 6W SMD LED’s …
We still can turn on the lights ;-), but when it’s turned off, we notice a visible “power leak” resulting in very very small visible light (not only during the first 5 minutes, but for hours). It’s enjoyable as “night light” and not realy disturbing, but where is this current leak coming from?!

***Are the relay contacts in VMB4RY not 100% isolated? Is this normal that we have some leak currents? ***

Any advise how to solve this? Do we need an external extra opto-coupler? Do we need to cut both cables?
I initially thought in direction of leak current from the “non-cut” 0-line (blue) and ground (yellow/green), we only cut 1 fase (red)
but since the aluminium housing of the spots is not grounded, this isn’t possible.

Main concerns:

  • extra power consumption, but as it’s less than a red status led :wink: I don’t expect much extra costs here
  • lamp life time reduction …

• suppressed relay contacts
•4 independent relay outputs :

  • switching capacity with a resistive load: 16A/230VAC max
  • switching capacity with an inductive load: 8A/230VAC max.

GU10 480-530LM 3000K 16-SMD LED Warm White Light Bulb (6.4W/AC220V)
Emitter Type: 5630 SMD LED
Total Emitters: 16
Power: 6.4W
Rated Voltage: 220V
Luminous Flux: 480-530LM

I think you’ve a current leakage through the suppression capacitor of the relay contacts due the low current the leds draw. This capacitor is there to avoid the “blobs” when switching on/off. A solution to this is to open the relays and remove this capacitor (it’s normally parallel over the contact). An other, more expensive solution is to use an other relay which is controlled by the velbus relay.

When relay is not active, how will current flow through relay contacts?

printed circuit board assembly china

to anders88,

a capacitor passes current when there is a ac voltage over them. explaination is the ac voltage switches 50 times per second the polarity so the capacitor charge and discharge 50 times per second. the current passes the relaycontact via the capacitor and runs throught the ledlamp because the resistance of the capacitor is high the current is low. So the led will weakly lights up. follow jeroends suggestion and remove the capacitor.


The leak current comes from the suppressed relay contacts.
These contacts are suppressed with a varistor.
In your case, removing of the varistor can fix the probem with the small visible light when it’s turned off.