Changing Fan Timeout
The fan ranges from 30-180 or you can choose [Always-on]. Fan is for cooling. It pulls air through dimmer modules and exhausts it through the top.
Dimmer on = Fan is on. When any dimmer is on at any level, the fan will be on.
All dimmers in an "off" state, in any given single rack, means the fan will be off in accordance with the fan timeout setting.