A power conversion unit performs an AC mode or DC mode conversion operation in which AC or DC power is converted to power driving a motor in order to supply a load. In response to the output of a sequence test signal instructing execution of a sequence test, a power source output switching switch shuts off the supply of a power from a power source to the power conversion unit. When the sequence test signal has been output and the supply of power to the power conversion unit has been shut off by means of the power source output switching switch, a control unit controls the AC mode or DC mode in order to cause the power conversion unit to execute a conversion operation corresponding to the power supplied to the power conversion unit in accordance with the switching history of sequence test signal output and non-output.