SQM21.18501 Siemens Actuator

Overview

The Siemens SQM21.18501 is a reversible electromotoric actuator specifically designed to control air dampers and fuel-air ratio valves on industrial and commercial oil and gas burners. As part of the heavy-duty SQM2 series, this actuator features a robust design with a die-cast aluminum gear housing and hardened steel shafts to ensure high precision and reliability. It is engineered to operate in conjunction with burner controls or switching devices, providing accurate positioning to optimize combustion efficiency and safety.

Features

• Heavy-duty design with nitrated gearwheels and hardened steel shafts for extended service life
• Integrated external position indicator for easy visual monitoring
• Reversible synchronous motor that is locking-proof
• Adjustable internal cams allow for precise setting of switching points
• Equipped with five auxiliary switches for flexible control integration
• Maintenance-free operation due to self-lubricating sinter-bronze bearings
• Impact-proof and heat-resistant plastic cover with an IP54 protection rating

Specifications

• Model: SQM21.18501
• Operating Voltage: AC 110 V (50/60 Hz)
• Nominal Torque: 20 Nm
• Starting Torque: 20 Nm
• Holding Torque: 12 Nm
• Running Time: 45 seconds for 90 degrees (at 50 Hz)
• Direction of Rotation: Clockwise (facing the drive shaft)
• Drive Shaft Diameter: 12 mm
• Power Consumption: 9 VA
• Protection Class: IP54
• Operating Temperature: -20 C to +60 C

Applications

• Control of air dampers in industrial and commercial burner systems
• Regulation of fuel-air mixture in oil and gas burners
• Use in HVAC systems, process heaters, and power generation plants
• Integration with Siemens burner controls such as the LMV or LME series
• Suitable for high-demand environments requiring precise valve and damper modulation