The MS4104, MS4109, MS4604, MS4609, MS8104 and MS8109 Fast-Acting, Two-Position Actuators are spring return direct coupled actuators (DCA) for Fire and Smoke dampers (on/off control). The actuator accepts an on/off signal from a single-pole, single-throw (SPST) controller. Reversible mounting allows actuator to be used for either clockwise (cw) or counterclockwise (ccw) spring rotation.

Features & Benefits:

• 30 lb-in. (3.4 Nm) or 80 lb-in. (9 Nm) minimum driving torque at 350°F (176°C)
• Reversible mounting facilitates use in either clockwise (cw) or counterclockwise (ccw) spring rotation
• Integral spring return ensures level of return torque
• Fifteen-second spring return timing
• No special cycling required during long-term holding
• No audible noise during holding
• Patent pending design eliminates need for limit switches to reduce power consumption
• Ninety-five degree angle of rotation
• Actuator holds rated torque at reduced power level
• Die-cast aluminum housing
• Housing design allows flush mounting to damper
• Models available with SPST position-indicating switches (7°, 85° stroke).

Certifications:

• Designed to operate reliably in smoke control systems requiring Underwriter’s Laboratories Inc UL555S ratings up to 350°F
• Non-UL marked models available