The FSAF24-BAL actuator provides spring return operation. There is no reversing switch. Mount in spring return closed position. The torque is asymmetrical giving 180 in-lb drive and 133 in-lb spring. A manual override winder and locking mechanism is provided. If the manual winder is used when the actuator is powered, the actuator will release, drive closed, and then go back to the potentiometer position. The actuator may not be mechanically parallelled or “piggybacked.” Each damper section should be controlled by a separate actuator. The FSAF24-BAL uses a DC motor which is controlled by a microchip. The actuator may be stalled anywhere during its rotation without damage. If power is removed, the damper will spring closed. Interlocks must be provided as necessary for life safety functions and to shut down fan if required.