| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an erroneous operation due to the transfer of noise generated by the high frequency switching operation of a semiconductor power converter to the peripheral electronic apparatuses. SOLUTION: Using a shielded cable as the input/output circuit cables 19, 22 of an inverter, one end portions of the shielded cables 19A, 22A are grounded to the ground pole 26. The exclusive ground poles are respectively used for inverter, electronic apparatuses 15, 25, panel cabinet 24 and motor 23. Using the shielded cable as the grounding lines 14A, 15A, 25A for the ground pole, one end portion of the shielded cable is grounded to the ground pole. Here, following selections are possible. Namely, the ground resistance of the ground pole is set to 10 Ω or less, the ground pole of the inverter is isolated by 10 m or more from the ground pole of the electronic apparatus and by 5 m or more from the ground pole for motor. In addition, a size of the shielded cable is identified, the inverter is insulated from the panel and the ground cable is provided in addition to the power cable as the output cables of the inverter. |
