Power conversion equipment which can detect a short circuit failure of series connected smoothing capacitors is provided. The equipment includes a capacitor failure detecting circuit having switch units, exciting resistors, contact resistors, and diodes. A switch unit is provided with an exciting circuit and a contact circuit, and when a predetermined current flows through the exciting circuit, the contact circuit is closed. The exciting circuit and an exciting resistor are alternately connected in series, and the contact circuit and a contact resistor are alternately connected in series. These serially-connected circuits are connected in parallel with each capacitor. When excitation of a switch circuit having a lowest potential is turned OFF, it is judged that one or more of the series connected capacitors has failed via a short circuit.