General description

Fire dampers prevent fire and smoke from spreading through ventilation systems.

They may be equipped with a thermal release mechanism.
Certified high reliable safety systems perform fire detection and the control of fire dampers.


The fire damper monitors fire alarm inputs. The fire alarms will be signalized with the dampers end switches. The dampers end switches are normally closed contacts by default. Since fire damper end switches have usually changeover contacts, the user can change the contact types of the end switches.

Motor driven fire/ smoke dampers can be open or closed during fire alarm. The damper position during fire alarm depends of the area it controls, if it has to be pressurized, de-pressurized or purged.

The normal position of motorized fire damper is always the position where the motor is powered. In case of fire alarm or power failure, the damper drives to the fire position due to its spring return actuator.

Attention: Never change the contact type of the damper command output otherwise you will get wrong behavior of the motorized damper and you can damage the ducts.

That's why the fire damper has no setting for fire position which can be open or closed during fire alarm. The damper can be mechanically adjusted to normally open or closed position.

Motor driven dampers have an optional maintenance run triggered by a maintenance switch.