Servo Motor / Actuator

A Servo Motor (or Actuator) is a precision electric motor used in modulating burners to position air dampers and fuel valves. It ensures the correct air-fuel ratio is maintained across the entire firing range.

Function in Combustion Control

In modern burners (especially those with Electronic Ratio Control), servo motors are the "muscles" that move the mechanical components.

1. Air Control: Adjusts the air damper opening to increase or decrease combustion air.
2. Fuel Control: Adjusts the butterfly valve or fuel regulator to match the fuel input to the air.
3. Positioning: They receive signals (e.g., 4-20mA or digital bus) from the Burner Controller and move to exact angles (e.g., 45.5°).

Features

• Feedback Potentiometer: Provides position feedback to the controller to verify the valve is where it should be.
• High Torque: Capable of moving heavy dampers against draft pressure.
• Fail-Safe: Some actuators have spring-return mechanisms to close valves on power loss.