Bulbs & LED's chat.. LED's are lit even though power is off.

I have a mixture of CBUS Dimmers and Relays.
There are lots of LED downlights that work great.
But then there are some LED downlights that still light up even though the power is switched off.

As a general rule, what bulbs should I look out for when purchasing bulbs for a CBUS system?

 

You need dimmable bulbs/LED downlights to start with. Some, dim better than others. What you are seeing is 'off-state leakage'. That is, even when a dimmer channel is off, there is a tiny amount of current leakage through to the load. This won't be visible on an old halogen load but can be on LED, particularly when there are a small number on the dimmer channel. To overcome this, you need a load correction device to be fitted by an elactrician on each of the dimmer channels where this problem occurs. Search this forum for more info on load correction device and off state leakage for more comprehensive info

 

For a CBUS system with dimmers and relays, choose LED downlights that are specifically labeled as "CBUS compatible" or "trailing edge dimmable." Avoid bulbs with high inrush currents or those that lack proper electronic drivers, as they can cause flickering or glowing when off. Always check the manufacturer's compatibility list to ensure optimal performance with your CBUS system.

 

If you have enough spare relay channels you could run the dimmers through them as well, using logic or scene controls to turn on or off