We call this Afterglow Effect and it happens due to the very high resistance of the LEDs. Some LED brands are better here, some worse. It also has to do with the number of LEDs per dimming channel. Even in the switched off state still flows a minimal current over the dimmer and the LED (with an incandescent lamp occurs the same, but it cannot be seen).
The solution is to use the compensator 6596:
Among others, the compensator prevents after-glow of low-voltage halogen or LED lamps in a deactivated state due to possible ripple voltage or activation via touch-dimmer without neutral conductor connection (parallel to the primary transformer side or to the lamp).
For more information please check: http://www.busch-jaeger-catalogue.com/6599-0-2290,artikel.html
Tags: Light Control