Cooling circuit for automatic air-conditioning system, has control unit for controlling capacity controlling mechanism, where unit has deficiency determining device for determining whether deficiency is present, when condition is detected

摘要

The circuit (R) has an air conditioning electronic control unit (ECU) for controlling a capacity controlling mechanism (38), which controls output capacity of a compressor (1). The ECU has a variable condition detecting device for detecting variable conditions of the circuit, and the output capacity of the compressor fluctuates in the condition. The ECU has a coolant deficiency determining device for determining coolant deficiency in the circuit, where the determining device determines whether the coolant deficiency is present, when the detecting device detects the condition.