Honeywell MS4104F1210 Fire and Smoke Damper Actuator 120V 30 lb-in Spring Return with 2 Auxiliary Switches

The Honeywell MS4104F1210 is a fast-acting, two-position spring return actuator designed specifically for fire and smoke damper control applications. This direct-coupled actuator accepts an on/off signal from a single-pole, single-throw (SPST) controller, and features two internal SPST auxiliary switches for position indication and system integration.

Key Features:

• Delivers 30 lb-in (3.4 N·m) minimum driving torque at 350°F (176°C), ensuring reliable operation in extreme conditions
• Reversible mounting facilitates use in either clockwise or counterclockwise spring rotation
• Fifteen-second spring return timing ensures rapid damper closure for critical fire safety applications
• Integral spring return ensures consistent level of return torque
• Patent pending design eliminates need for limit switches to reduce power consumption
• 95° ±3° stroke, mechanically limited
• Die-cast aluminum housing with flush mounting capability

This actuator is designed to meet both UL-555 and UL-555S 350°F safety requirements for combined fire and smoke applications. The unit requires no special cycling during long-term holding and produces no audible noise during holding operation. Suitable for HVAC systems in commercial and industrial buildings where fire and smoke damper control is critical for life safety systems.