ABB 6517U-101-500 Manual Del Usuario página 21

Important information
1.1.1.12
Recommendation for protecting the devices
Extended operation of an unloaded transformer (e.g. with a
faulty bulb) connected to a dimmer may destroy both the
transformer and the dimmer. This is caused by a possible
voltage rise which may occur between an unloaded
transformer and the dimmer.
Caution!
Reduce minimum brightness only so that the lighting is still
visible.