All Aprilaire zoned comfort control panels will work with normally-open, powered-closed zone dampers as well as normally-closed, powered-open zone dampers. All Aprilaire zone dampers are normally-open, powered-closed dampers. This means with no power going to the zone damper it will always be open. When a zone calls for conditioning, the Aprilaire zone dampers in the zones not calling will be sent a continuous 24 volt power supply from the Aprilaire zoned comfort control panel to be powered closed. The Aprilaire zoned comfort control panel will continuously power the normally-open, powered-closed zone damper until the conditioned air call in the calling zone is complete. Once the call is complete, the continuous 24 volt power supply is stopped by the Aprilaire zoned comfort control panel and the Aprilaire zone dampers in the non-calling zones return to their normally-open position.
The NC and C terminals on the Aprilaire zoned comfort control panel send out 24 volts continuously while the Aprilaire zoned comfort control panel is not making any calls for conditioned air. If a normally-closed, powered-open damper is used and connected to the NC and C terminals, our Aprilaire zoned comfort control panel will send a continuous 24 volt power supply to the zone damper to keep it open. The zone damper must be capable of receiving continuous 24 volt power. The manufacturer of the normally-closed, power-open damper you selected should be able to determine whether or not their dampers can function reliably with continuous 24 volt power.
All Aprilaire zoned comfort control panels will work with normally-open, powered-closed zone dampers as well as normally-closed, powered-open zone dampers and with dampers which are powered-open and powered-closed. All Aprilaire zone dampers are normally-open, powered-closed dampers. This means with no power going to the zone damper it will always be open. When a zone calls for conditioning, the Aprilaire zone dampers in the zones not calling will be sent a continuous 24 volt power supply from the Aprilaire zoned comfort control panel to be powered closed. The Aprilaire zoned comfort control panel will continuously power the normally-open, powered-closed zone damper until the conditioned air call in the calling zone is complete. Once the call is complete, the continuous 24 volt power supply is stopped by the Aprilaire zoned comfort control panel and the Aprilaire zone dampers in the non-calling zones return to their normally-open position.
When a powered-open, powered-closed damper is used the power- to- open terminal on the damper wires to the NC terminal on the Aprilaire zoned comfort control panel, the power- to- close terminal on the damper wires to the NO terminal on the Aprilaire zoned comfort control panel and the Common terminal on the damper wires to C terminal on the Aprilaire zoned comfort control panel. Since the NC and C terminals on the Aprilaire zoned comfort control panel send out 24 volts continuously while the Aprilaire zoned comfort control panel is not making any calls for conditioned air, our Aprilaire zoned comfort control panel will send a continuous 24 volt power supply to the zone damper to keep it open. When a zone calls for conditioned air, 24 volts is sent out the NO and C terminals to power closed the zoned dampers in the zones not requiring conditioned air. The Aprilaire zoned comfort control panel will continue to send 24 volt power out the NC and C terminals to the zone damper in the zone calling for conditioned air to keep it open. Once the call is complete 24 volt power is removed from NO and C terminals in the non-calling zones and instead 24 volt powers is sent out the NC and C terminals to power the dampers back open. The zone damper must be capable of receiving continuous 24 volt power. The manufacturer of the normally-closed, power-open damper you selected should be able to determine whether or not their dampers can function reliably with continuous 24 volt power.