Mitsubishi Electric FR-A720-0.4K Instruction Manual page 10

4.30 Check and clear of the faults history ............................................................ 399
5 PROTECTIVE FUNCTIONS
5.1 Reset method of protective function ............................................................. 402
5.2 List of fault or alarm display ........................................................................... 403
5.3 Causes and corrective actions ....................................................................... 404
5.4 Correspondences between digital and actual characters ........................... 418
5.5 Check first when you have a trouble ............................................................. 419
5.5.1 Motor does not start............................................................................................................... 419
5.5.2 Motor or machine is making abnormal acoustic noise........................................................... 421
5.5.3 Inverter generates abnormal noise........................................................................................ 421
5.5.4 Motor generates heat abnormally .......................................................................................... 421
5.5.5 Motor rotates in the opposite direction .................................................................................. 422
5.5.6 Speed greatly differs from the setting .................................................................................... 422
5.5.7 Acceleration/deceleration is not smooth ................................................................................ 422
5.5.8 Speed varies during operation............................................................................................... 423
5.5.9 Operation mode is not changed properly .............................................................................. 424
5.5.10 Operation panel (FR-DU07) display is not operating............................................................. 424
5.5.11 Motor current is too large....................................................................................................... 424
5.5.12 Speed does not accelerate .................................................................................................... 425
5.5.13 Unable to write parameter setting.......................................................................................... 425
5.5.14 Power lamp is not lit .............................................................................................................. 425
6 PRECAUTIONS FOR MAINTENANCE AND INSPECTION
6.1 Inspection item................................................................................................. 428
6.1.1 Daily inspection ..................................................................................................................... 428
6.1.2 Periodic inspection ................................................................................................................ 428
6.1.3 Daily and periodic inspection ................................................................................................. 429
6.1.4 Display of the life of the inverter parts ................................................................................... 430
6.1.5 Checking the inverter and converter modules ....................................................................... 430
6.1.6 Cleaning ................................................................................................................................ 430
6.1.7 Replacement of parts ............................................................................................................ 431
6.1.8 Inverter replacement.............................................................................................................. 434
6.2 Measurement of main circuit voltages, currents and powers ..................... 435
6.2.1 Measurement of powers ........................................................................................................ 437
6.2.2 Measurement of voltages and use of PT ............................................................................... 437
6.2.3 Measurement of currents....................................................................................................... 438
6.2.4 Use of CT and transducer ..................................................................................................... 438
401
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VII