What is the function of an ambient temperature switch in a non-ATC system?

The function of an ambient temperature switch in a non-automatic temperature control (non-ATC) system is primarily to inhibit compressor clutch operation. This switch detects the temperature of the ambient environment and plays a crucial role in regulating the operation of the air conditioning system to prevent potential damage and ensure efficient functioning.

When the ambient temperature is too low, the switch will signal the compressor not to engage. This protection mechanism is essential because running the compressor in low temperatures can lead to compressor damage due to the risk of liquid refrigerant returning to the compressor. Moreover, it helps in preventing excessive moisture from building up within the system, which could cause problems with performance and reliability.

While other alternatives like controlling fan speed and adjusting duct temperature or detecting refrigerant levels play important roles within different systems, they are not the primary functions of an ambient temperature switch in non-ATC systems. Thus, inhibiting the compressor clutch's operation is the correct and most contextually relevant function of this switch.