What is the function of a thermal overload in HVAC systems?

The function of a thermal overload in HVAC systems is primarily to prevent overheating of the unit. It serves as a protective device that monitors the temperature of the system and interrupts the electrical supply to the compressor when it detects excessive heat. This is crucial because overheating can lead to serious damage, reduced efficiency, or even complete failure of the compressor. By shutting down the system before it reaches a critical temperature, the thermal overload contributes to the longevity and reliability of the HVAC equipment, ensuring that it operates safely under optimal conditions.

In contrast, increasing system efficiency, switching the compressor on, or regulating air flow are not roles played by the thermal overload. Each of these functions relates to different components and systems within HVAC design and operation.