Rotary speed control for QuietAir QT150VS only.

Fan Speed Controlling
The round knob on the controller front is connected to a potentiometer. This is used to control a 0-10V DC output from the fan.
The controlled voltage is then returned to the fan, giving smooth fan speed control.

Minimum Fan Speed Facility
Incorporated in the controller is a potentiometer to set a minimum fan speed. This will regulate the return voltage to the fan.
The minimum voltage range using this facility can be adjusted between approximately 1.3V DC and 6.7V DC.

Standby and On Switching
The round knob on the controller front is also used as a fan standby and on switch. Press and release the knob to switch fan on.
Pressing and releasing the knob again will put the fan into standby mode. LED back lighting indicates fan ON/OFF status.