Siemens Actuator Servomotor SQN3 / SQN4 Series

Siemens Actuator Servomotor SQN3 / SQN4 Series – Industrial Burner Damper Control Actuators

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.

Key Features of Siemens SQN3 / SQN4 Series

• 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.

Applications in Industrial Burner Systems

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 SQN3 / SQN4 Series are electromotoric actuators designed for position control of air and gas dampers in industrial burner systems. They feature synchronous motors and maintenance-free gear trains, along with adjustable cams, end switches, and model-dependent auxiliary switches. Available power supply options include AC 100–110 V or AC 220–240 V at 50/60 Hz, depending on the model. An IP40 protection rating applies when appropriate cable entries and mounting hardware are used. These actuators are suitable for controlling combustion air and fuel supply according to burner load requirements.