Spring-operated "separate function" control mechanism, used in cut-off fire dampers – current break control

The only difference is to use an electromagnetic release device without a permanent magnet instead of an electromagnetic release with a permanent magnet. This electromagnet must be energized in order to create the magnetic field holding the bolt – requires a continuous supply of control energy.

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 interruption.

In the case of a signal from the CSP in the form of a current interruption in the power supply of the electromagnetic release, its magnetic field disappears, then the bolt blocking the spring drive of the damper is released. A spring installed directly in the damper guarantees its very quick transition to the safety position. Closing the hatch takes up to a few seconds. Return the hatch to the waiting position – the spring tension of the damper's drive is possible by applying the control voltage to the electromagnetic release, and then applying power to the electromechanical rotary actuator, the main element of which is an electric motor. This action should follow the activation of the remote-restoration switch from the zone to standby, in which the inspection was made (intervention) 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. 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. The discussed solution has the same structure as the design of the damper with the control mechanism, subject to a difference which is invisible in external appearance, which is the electromagnetic trigger. In the field of control, mechanisms with "separation of functions" with spring actuator, used in cut-off fire dampers and controlled by a power cut, have the same requirements, for mechanisms "without separation of functions" with a spring drive and also controlled by a current break. The only difference is the separation or non-separation of functions, will have different cabling requirements and the need for a control separation interface, which will be discussed later in this chapter.