Application:
The type FSLF spring-return actuator is intended for the
operation of smoke and combination fire and smoke dampers
in ventilation and air-conditioning systems. The actuator will
meet requirements of UL555 and UL555S when tested as an
assembly with the damper and will meet requirements of UBC
for 15 second opening and closing.
Square footage of damper operated will depend on make and
model and the temperature required.
Operation:
Mounting of the actuator to the damper axle shaft or jackshaft is
via a cold-weld clamp. Teeth in the clamp and V-bolt dig into
the metal of both solid and hollow shafts maintaining a perfect
connection. The specially designed clamp will not crush hollow
shafts. The bottom end of the actuator is held by an anti-rotation
strap or by a stud provided by the damper manufacturer.
The actuator is mounted in its fail safe position with the
damper blade(s) closed. Upon applying power, the actuator
drives the damper to the open position. The internal spring is
tensioned at the same time. If the power supply is interrupted,
the spring moves the damper back to its fail-safe position.