The Hand/Off/Auto (HOA) control is the latest addition to Greenheck’s line of Vari-Green controls that optimize ventilation system efficiency.
The compact HOA control can replace a Vari-Green transformer and provide a 24V power source from existing line voltage at the fan. The fan can be enabled by using a dry contact closure or by providing a voltage (12-120V) allowing the control to easily integrate the fan into a variety of systems. With only three buttons and an LED display, the compact HOA control is both user-friendly and functional. Users have the ability to run the fan in hand mode for balancing, troubleshooting or to operate the fan before external controls are installed and operational.
The control also has the ability to remotely enable the fan and use a speed reference that is set either on the HOA control or provided by a third party. A Fireman’s mode provides another input to override all other modes and send the fan to any speed chosen, 0% or 20-100%. The versatile unit can also be selected to operate as a stand-alone control or as an accessory to other Vari-Green controls.