Siemens Combustion SQN71.403R19 Reversing Actuator 10 SEC 120 VAC

The Siemens Combustion SQN71.403R19 Reversing Actuator is a motor-driven rotary control part that positions dampers or fuel-air control elements in HVAC combustion equipment by rotating through a timed cycle and reversing direction as required for flow regulation. It operates on a 120 VAC power supply with a 10-second full travel cycle, converting electrical input into controlled rotary motion through an internal synchronous motor and gear train mechanism. The actuator mounts directly to compatible damper or valve shafts and interfaces with the control system wiring for coordinated sequencing. Controlled rotation supports accurate airflow adjustment, stable combustion behavior, and consistent burner operations.