1. A motor driver comprising:a converter that converts an AC voltage into a DC voltage and outputs the DC voltage;
an inverter that inverts the input DC voltage into a multi-phase AC voltage for motor driving;
a short bar fixed to an output terminal of the converter and an input terminal of the inverter by screw fastening;
a first voltage detector that detects a voltage across the output terminals of the converter;
a second voltage detector that detects a voltage across the input terminals of the inverter; and
a reporting unit that provides, when a difference between the voltage detected by the first voltage detector and the voltage detected by the second voltage detector exceeds a predetermined threshold, a report relating thereto.