SQM40.241A21 Siemens Actuator

Overview

The Siemens SQM40.241A21 is a high-precision electromotoric actuator designed for the accurate positioning of air and gas dampers, butterfly valves, and oil pressure controllers. This modulating rotary actuator is engineered for use in industrial and commercial combustion plants, specifically for medium to high-capacity oil and gas burners. Featuring a robust NEMA 4 rated housing, it is built to withstand demanding environments while providing reliable, load-dependent control of fuel and combustion air. The actuator supports multiple control signals, including 4-20 mA, 0-135 Ohm, and 2-10 VDC, making it a versatile solution for linkageless or linkage-based burner management systems.

Features

• Flexible Control Input: Compatible with 4-20 mA, 0-135 Ohm, and 2-10 VDC analog control signals
• Robust Construction: Die-cast aluminum lower housing with an impact-proof and heat-resistant plastic cover
• Environmental Protection: NEMA 4 / IP66 rated enclosure allows for outdoor use without additional weather shields
• Manual Disengagement: Features a coupling pin (K1) to manually disengage the drive shaft from the motor for quick alignment
• Internal Position Indication: Includes scales for easy adjustment of switching points and position monitoring
• Mounting Versatility: Can be mounted in any orientation, simplifying installation in complex burner configurations

Specifications

• Model: SQM40.241A21
• Operating Voltage: AC 230 V (50/60 Hz)
• Rated Torque: 10 Nm (approx. 90 in-lb)
• Running Time: 30 seconds for 90 degrees
• Direction of Rotation: Counter-clockwise (CCW)
• Nominal Angle of Rotation: 90 degrees
• Drive Shaft: 10 mm diameter with Woodruff key
• Potentiometer: Single potentiometer included (European version)
• Operating Temperature: -20 C to +60 C
• Power Consumption: 10 VA

Applications

• Load-dependent control of gas, oil, and combustion air flow in industrial burners
• Precise positioning of air dampers and gas butterfly valves
• Use in thermal process plants and HVAC boiler systems
• Direct control via burner management systems or in connection with modulating controllers
• Replacement for legacy actuators in existing combustion trains and thermal processes