| 摘要 |
PROBLEM TO BE SOLVED: To determine leakage of a motor effectively. SOLUTION: An inverter comprises a rectifying circuit 2 for converting an AC power supply 1 into a DC power supply, a leak detection circuit 3 having a zero-phase current transformer, an inverter circuit 4 comprising power switching means 4a-4f for converting the DC power supply from the rectifying circuit 2 into an AC power supply, a motor 5 connected with the output of the inverter circuit 4, and means 6 for on/off controlling the power switching means 4a-4f wherein the inverter circuit 4 is arranged as a three-phase full-wave circuit by three power switching means on the high potential side and three power switching means on the low potential side. When a motor is started, the control means turns on/off at least one of the high potential side power switching means or the low potential side power switching means intermittently for a specified period and determines leakage of the motor based on the output from the leak detection circuit. |
