Patent ID: 9714781
Date: 2017-07-25
CPC Classifications: F25B,F25D,H02H,H02P

Claim:
1. A transport refrigeration apparatus including a refrigerant circuit in which a refrigeration cycle is performed, comprising: a fan configured to supply air to an air heat exchanger connected to the refrigerant circuit; a fan motor configured to drive the fan; a power supply sensor that detects a supply frequency and a supply voltage of a power supply configured to supply power to the fan motor; an abnormality determiner configured to compare a current value for current flowing through the fan motor with a preset current threshold to determine occurrence of a motor abnormality of the fan motor; and a threshold changer configured to change the current threshold of the abnormality determiner in accordance with the detected supply frequency and the detected supply voltage of the power supply configured to supply power to the fan motor, wherein the threshold changer stores a plurality of predetermined correlations between the detected supply voltage and the current threshold for respective supply frequencies, each of the plurality of correlations defining a different relationship between the current threshold and the supply voltage, and when the power supply sensor detects a new supply frequency, the threshold changer calculates based on one of the plurality of correlations corresponding to the new supply frequency, to determine the current threshold to coincide with the detected supply voltage.