Siemens Actuator SQN90.220A2799

The Siemens SQN90.220A2799 is an actuator designed for precise air damper control in small and medium power burners. It operates on a supply voltage of 220 V and delivers a nominal torque of 2.4 Nm. This device is part of the Actuators product group and is used to regulate the fuel-air mixture for efficient combustion.

When selecting an actuator of this type, ensure the supply voltage, torque, and control signal format (e.g., three-point, 0-10 V, or on/off) match the system requirements. The shaft or coupling pattern and total rotation angle must correspond to the damper or valve linkage. Verify the mounting dimensions and auxiliary switch configurations to ensure compatibility with the existing setup.

Common failure modes include stripped gear trains due to mechanical overload, failed end switches that no longer signal correct position, and seized valve stems after prolonged inactivity. Symptoms may include improper damper positioning, burner lockout, or failure to modulate correctly. Check for free movement of the damper linkage and verify power and control signals before replacement.