Mitsubishi Electric FR-E800 Instruction Manual page 158

No. Condition
Speed command varies.
Motor speed
4
fluctuates. Torque shortage.
Speed control gain is not
suitable for the machine.
(Resonance occurs.)
Speed control gain is too
Hunting (vibration or
high.
acoustic noise)
5 Torque control gain is
occurs in the motor
too high.
or the machine.
Motor wiring is incorrect. • Check the wiring.
Acceleration/
Torque shortage.
deceleration time is
6
different from the
Load inertia is too high.
setting.
Speed control gain is not
suitable for the machine.
Response is slow
Machine movement
7
because of the inverter's
is unstable.
acceleration/
deceleration time
setting.
High carrier frequency is
affecting the motor
Rotation ripple
rotation.
8 occurs during the
low-speed operation.
Speed control gain is too
low.
Parameters referred to
Pr.72 PWM frequency selectionpage 249
Pr.80 Motor capacity, Pr.81 Number of motor
Pr.125 Terminal 2 frequency setting gain frequency, Pr.126 Terminal 4 frequency setting gain
Pr.359 Encoder rotation direction, Pr.369 Number of encoder
Pr.822 Speed setting filter 1page 398
Pr.824 Torque control P gain 1 (current loop proportional
Possible cause
• Check that the speed command sent from the controller is correct. (Take EMC
measures.)
• Set Pr.72 lower.
• Set Pr.822 Speed setting filter 1 higher. (Refer to
• Raise the torque limit.
(Refer to the torque limit for speed control on
• Adjust Pr.820 Speed control P gain 1 and Pr.821 Speed control integral time
1.
• Set Pr.820 lower and Pr.821 higher.
• Set Pr.824 Torque control P gain 1 (current loop proportional gain) lower.
• Raise the torque limit.
(Refer to the torque limit for speed control on
• Set acceleration/deceleration time suitable for the load.
• Adjust Pr.820 and Pr.821.
• Set the optimum acceleration/deceleration time.
• Set Pr.72 lower.
• Set Pr.820 higher.
polespage 115
pulsespage 452
gain)page 173
Countermeasure
page 398.)
page 139.)
page 139.)
frequencypage 400
5.9 Troubleshooting in the speed control
1
2
3
4
5
6
7
8
9
10
157
5. Speed Control