Contact for external safety device

An external safety device (differential pressure controller, smoke detector, fire alarm control panel) can be connected to terminal X2 (12 V).

Air-ventilated fireplaces

If the ventilation unit is being operated at the same time as an air-ventilated fireplace, a differential pressure controller is needed as the safety device. The differential pressure controller prevents the ventilation system from being operated if the air pressure in the fireplace’s installation area falls by the permitted pressure in relation to the flue draught.

If this happens, the ventilation unit switches off. The differential pressure controller is connected as a normally closed contact. When the impermissible partial vacuum is reached, the differential pressure controller opens and thereby directly interrupts the current supply to the fans. An electric heat register, if present, shuts off too.

The note “External safety shutdown triggered” appears on the operating unit.

If the differential pressure controller is closed, the ventilation unit starts up again.

External safety device

If the safety device connected to terminal X2 (12 V) is triggered (pressure error, smoke etc.), the ventilation unit shuts down automatically → parameter Acknowledgement of external safety device.