The First Company CB500 Circuit Board 3 Speed is an electronic control module designed to manage fan motor operation in HVAC air handlers and fan coil units. It regulates three-speed fan settings by processing thermostat signals and distributing appropriate electrical output to the motor. Commonly used in residential and light commercial heating and cooling systems, it ensures precise airflow control and system responsiveness. This circuit board enhances operational efficiency, supports consistent temperature distribution, reduces energy consumption, and contributes to reliable performance and extended equipment lifespan.