| 摘要 |
PROBLEM TO BE SOLVED: To provide a safe motor drive power conversion device.SOLUTION: Only when a main power switch 13 is open, a resistance value measurement switch 34 is closed and in the state where input-side contacts 30-1 to 30-3 and a short-circuit contact 30-4 are closed, as first inspection, both terminals of a total value R33 of a series of three dynamic brake resistors 33-1 to 33-3 are short-circuited by the short-circuit contact 30-4 of a brake-side switch, thereby detecting whether a short-circuit state is normal or not, and detecting cable disconnection from a DB failure detection board 10 to the dynamic brake resistors 33-1 to 33-3, a contact defect of the short-circuit contact 30-4 of the brake-side switch and a contact defect of the resistance value measurement switch 34. Next, second inspection is performed for determining whether the total value R33 of a series of the three dynamic brake resistors 33-1 to 33-3 is settled within an allowable range. A PLC 6 compares the first inspection and the second inspection with inspection situation patterns registered beforehand. If there is any abnormality, an alarm is raised to a worker and when all the alarms are canceled, driving is enabled to be performed. |
