SQM33.550A9 Siemens Actuator

Overview

The Siemens SQM33.550A9 is a high-precision electromotoric actuator designed for the load-dependent control of gas dampers, air dampers, or oil control valves in industrial and commercial burner applications. Engineered for use with Siemens burner controls, such as the LMV3 series, this reversing actuator provides reliable parallel positioning and fuel-air ratio management. It features a robust stepper motor and a die-cast aluminum housing with an impact-proof plastic cover, making it suitable for demanding combustion environments.

Features

• High-precision stepper motor provides accurate positioning for optimal combustion efficiency
• Internal optical feedback system ensures reliable real-time position monitoring without mechanical wear
• Integrated 12-foot (3.6m) connecting cable with ferrules for streamlined installation
• Clockwise and counterclockwise rotation options selectable via the basic burner control unit
• Self-holding torque mechanism maintains position even when the unit is under load
• Durable IP54-rated construction protects internal components from dust and splashing water
• Maintenance-free gear train with permanent lubrication and low backlash for long service life

Specifications

• Model: SQM33.550A9
• Operating Voltage: 24 V AC/DC (+/- 20%)
• Rated Output Torque: 3 Nm (approximately 27 in-lb)
• Holding Torque (Power Applied): 3 Nm
• Holding Torque (Power Not Applied): 2.6 Nm
• Running Time for 90 Degrees: 5 to 120 seconds (dependent on the basic unit)
• Drive Shaft: 10mm D shaped shaft
• Angular Adjustment: Maximum 90 degrees
• Operating Temperature: -4 F to 140 F (-20 C to 60 C)
• Power Consumption: Maximum 10 W
• Protection Class: IP54 (to EN 60 529-1)

Applications

• Precise modulation of air dampers and gas butterfly valves in forced draft burners
• Fuel-air ratio control in commercial and industrial heating systems
• Integration with Siemens LMV27 and LMV37 linkageless burner management systems
• Direct drive for oil control valves in dual-fuel burner configurations
• Use in steam boilers and process heat generation plants requiring continuous operation efficiency