MS4120F; MS4620F,S; MS8120F,S; S2024-F; S20230-F FAST-ACTING, TWO-POSITION ACTUATORS
The actuators are designed for use in Smoke Control Systems.
If power fails, the actuator spring returns to the 0° position. The
actuator mounts flush with the damper box. The actuator drives
from 0° to 95° and spring returns back to 0°.
The actuators are operated by an spst two-position controller.
When using an spst two-position controller, the actuator drives
to the damper fully open position when controller contact
makes and spring returns to the damper fully closed position
when controller contact breaks. The actuator drops to holding
power level on detection of stall, independent of hub position.
The actuator and the internal spring are designed so that no
special cycling during long-term holding is required. Honeywell
recommends following all local, state, and national codes for
periodic testing of the entire smoke control system. Refer to
National Fire Protection Association (NFPA) National Fire
: NFPA90A, NFPA92A, and NFPA92B for your
Some models include auxiliary switches (see Table 1).
SPST Switches (Table 5)
See Fig. 6 through 8 for SPST auxiliary switch wiring.
Table 5. SPST Auxiliary Switch Operation.
less than 7
greater than 85
NOTE: Both sets of contacts are open when the actuator is
between 7° and 85°.
SPDT Switches (Fig. 11)
See Fig. 9 through 11 for SPDT auxiliary switch wiring.
Fig. 11. SPDT auxiliary switch operation.
(degrees from fully closed position)
greater than 7
less than 85