Siemens Actuator Servomotor SQN3 / SQN4 Series are electromotoric actuators designed to drive and control the positions of air dampers (Air Damper), gas dampers (Gas Damper), and related control valves in small- to medium-capacity oil and gas burners (Oil & Gas Burner). They help regulate combustion air and fuel supply according to the operating load of the combustion system.
The actuators use reversible synchronous motors that transmit power through a gear train to the drive shaft. They feature adjustable cams, end switches, and auxiliary switches, depending on the model. Switching points can be adjusted in 1° increments, with internal and external position indicators for monitoring actuator position. The gear train is designed for maintenance-free operation under normal conditions.
Reversible synchronous motor for damper positioning and control.
SQN30 models rotate counterclockwise, while SQN31 and SQN41 models rotate clockwise.
Standard SQN3 models provide 0.8–3 Nm of holding torque and a 90° running time of approximately 4.5–30 seconds.
SQN4 models provide 6 Nm of torque and a 90° running time of approximately 120 seconds. Certain SQN31 models also provide 6 Nm.
Available for AC 100–110 V or AC 220–240 V power supplies, depending on the model, at 50–60 Hz.
Equipped with adjustable cams, end switches, and auxiliary switches for setting operating positions.
Impact-resistant, heat-resistant plastic housing with an IP40 protection rating under specified installation conditions.
Siemens SQN3 / SQN4 Series can be integrated with Siemens LOA, LMO, LMG, and LFL burner controls, as well as P, PI, or PID controllers such as Siemens RWF, depending on the actuator model and supported wiring configuration. They are suitable for 2-stage and modulating burner control systems used in boiler burners, industrial furnaces, and hot air generators.
Before selecting or replacing an actuator, verify the model number, operating and holding torque, 90° running time, direction of rotation, supply voltage, drive shaft configuration, and wiring diagram to ensure compatibility with the existing burner system. If position feedback is required, confirm whether the selected model supports potentiometer installation.
Siemens Actuator Servomotor SQN3 / SQN4 Series are electromotoric actuators designed to drive and control the positions of air dampers, gas dampers, and control valves in small- to medium-capacity oil and gas burner systems. These actuators feature reversible synchronous motors. Standard SQN3 Series models provide a holding torque of 0.8–3 Nm and a 90° running time of approximately 4.5–30 seconds, while SQN4 Series actuators provide 6 Nm of torque and a 90° running time of approximately 120 seconds. SQN30 models rotate counterclockwise, whereas SQN31 and SQN41 models rotate clockwise. Depending on the specific model and wiring configuration, they can operate with Siemens LOA, LMO, LMG, and LFL burner controls, as well as PID controllers such as Siemens RWF. They are suitable for controlling combustion air and fuel supply in industrial burner applications.
