A power conversion device includes: a power conversion circuit that outputs power to a power output terminals to which electric cables of a power cable for supplying AC power to a motor is connected; an encoder circuit that outputs encoder information on the basis of angle information input to an information input terminal and supplied from signal lines of a signal transmission cable; a control unit that outputs a control signal that controls the power conversion circuit on the basis of the encoder information supplied from the encoder circuit; a shield terminal connected to a shield of the signal transmission cable which is electrically connected to a ground line of a power cable on the motor side; and a determination unit that detects a current input to the shield terminal and flowing through the shield of the signal transmission cable, and outputs disconnection detection information for disconnection in the shield.