In case of, when moving to the safety position, it is initiated by an electromagnetic release that releases the bolt of the damper spring drive, and transition to the standby position is ensured by an independently powered electromechanical rotary actuator, we say, that it is a solution of the control mechanism "with separation of functions" of the safety from the function of restoring the waiting position. During normal operation of the ventilation and air conditioning system, the spring of the damper's drive remains under tension, thus storing the potential energy necessary to close the damper. It is locked in the waiting position by a bolt, held by an electromagnetic trigger with a strong permanent magnet. Therefore, no control energy is required in standby. Additionally, the bolt is coupled via a lever with a thermal release – most often fusible or ampoule and with a manual trigger. The damper can be moved to the safety position in three cases:

– temperature rise above the activation temperature of the thermal release,
– uruchomienia wyzwalacza ręcznego,
– control signal from the CSP – current pulse.

In the case of a signal from the CSP of a current pulse energizing the electromagnetic trip unit, a magnetic field opposite to the magnetic field of a permanent magnet is created, As a result, the bolt blocking the spring drive of the damper is released. A spring installed directly in the damper guarantees a very quick transition of the damper to the safety position. Closing the hatch takes up to a few seconds, thus incomparably faster than with a control mechanism without separation of functions. Return the hatch to the waiting position – the spring tension of the damper's drive is possible by supplying power to the electromechanical rotary actuator, the main element of which is an electric motor. This should be done after activating the zone remote recovery switch, on which the inspection was carried out or by manually arming these dampers, which are not equipped with the remote recovery standby function. In this way, the obligation to verify by the facility security services each fire hazard signal in place is enforced, from which this signal comes, before the normal functioning of the CSP is restored. For dampers with control mechanisms with separation of functions, there is no need for additional control separation interfaces yes, as for dampers with mechanisms without functional separation. Signaling of the beginning and end of each change of the damper partition position is provided by limit switches, which complement the spring drive of the damper.
Due to the need to apply voltage to the electromagnet coil in order to enable the damper to move to the safety position, it is essential that:
-the trigger was powered by a power supply cooperating with the battery,
– w przypadku gdy przewód łączący sterownik z wyzwalaczem elektromagnetycznym klapy ma większą długość niż 2 m this connection should be supervised.