Appendix 5 Test Operation - Mitsubishi Electric MDS-B-SPJ2 Series Specification Manual

Appendix 5 Test operation

(1) Method for rotating the motor in an open loop
< Purpose >
When the below phenomena occur during motor rotation, this operation is used to investigate the
causes.
1. There is a lot of motor noise and vibration.
2. Alarm 23 (EXCESSIVE SPEED ERROR)
3. The motor rotates between 10 to 100 rpm, and will not rotate faster.
4. Rotation is irregular. Hunting occurs.
5. The motor does not rotate as commanded.
< Method >
1. Set parameter SP038: bitF from 0 to 1, and enter an open loop status by turning the power
OFF/ON.
2. After canceling the emergency stop signal, turn the forward run command (SRN) ON, and
gradually raise the S commands from zero to rotate the motor.
3. Set parameter SP038: bitF from 1 back to 0, and return to the normal operation mode by
turning the power OFF/ON.
< Note > The normal operation mode cannot be returned to by only turning the power
< Phenomena and fault causes >
Judge the fault cause from the phenomenon that occurs when the motor is rotated using the
method above.
Motor rotation
direction
Same as above.
Same as above.
(2) Method for coasting the motor
< Purpose >
When a lot of vibration and noise occur during motor rotation, the motor can be put into a
coasting state to determine whether mechanical factors (balance, resonance) or electrical
factors (motor rotation irregularity, etc.) are responsible.
If the vibration and noise stop when the motor is put into a coasting state, then electrical
factors can be judged as the cause. If the vibration and noise continue in the coasting state at
the same level as during motor-driven operation, then mechanical factors can be judged as
the cause.
< Method >
1. Rotate the motor at the max. speed.
2. Turn the NC power OFF while the motor is rotating at max. speed, and put the motor in a
coasting state.
< Note > The method for turning the NC power OFF differs according to the
OFF/ON. The parameter must be returned to 0.
Controller
speed display
Normal display
Stays at zero, or
changes greatly.
Normal display
Same as above.
manufacturing specifications of each maker. Before carrying out this method,
please check the specifications of the NC being used to make sure of the
method to turn the NC OFF, and that there is no problem with suddenly turning
the NC power OFF.
Appendix
Rotation status
Smooth rotation
Smooth rotation
The speed does not
change, even when the
speed command is raised.
The motor stays stopped,
hunting occurs.
A − 9
Fault cause
The motor U, V and W
phase sequence is
incorrect.
The CN2 cable wiring is
incorrect. There is a motor
built-in encoder error.
The speed command signal
is not being correctly
transmitted.
There is a controller error.