Shut-off damper ADC is a 2-position, motorized damper without end switch. The damper is powered open with 24V AC, and is normally closed with spring return. Power supply wiring is connected to the lead wires attached to the damper motor. Positive closure is provided by a tight seal.

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Note: If you are using a fresh air appliance (HRV or ERV) which uses FAN Defrost in a simplified installation, i.e. connecting appliance’s supply air duct to a furnace's return air duct, the appliance must operate continuously. In case it is turned off, the furnace will continue to draw in outdoor air directly into itself without re-heating or re-cooling. If the appliance is installed such that the homeowner may turn it off during the cold or hot seasons, we recommend installing a motorized damper ADC6 between the appliance’s supply air and the furnace's return air duct that closes when the appliance is not operating.