Troubleshooting In Torque Control - Mitsubishi Electric 800 Series Instruction Manual

6.6

Troubleshooting in torque control

Sensorless Sensorless Sensorless
Condition
Torque control does not
1
operate properly.
When a small torque
command is given, the
2 motor rotates in a
direction opposite to the
start signal.
Torque control cannot
operate normally during
3 acceleration/
deceleration.
The motor vibrates.
Parameters referred to
Pr.72 PWM frequency selectionpage 146
Pr.178 to Pr.189 (Input terminal function
Pr.800 Control method selectionpage 86
Pr.807 Speed limit selectionpage 120
C38 to C41 (torque setting voltage (current)
124
6. Torque control
6.6 Troubleshooting in torque control
Possible cause
• Motor wiring is incorrect.
• Pr.800 Control method selection
is not appropriate.
• The speed limit value has not been
input.
• Torque command varies.
• The torque command and the torque
recognized by the inverter are
different.
• Torque offset calibration is
inaccurate.
• Speed limit is operating.
(Speed limit may operate because
the speed limit value will increase or
decrease according to acceleration/
deceleration time setting of Pr.7 and
Pr.8 when Pr.807 = "0".)
selection)page 283
bias/gain)page 278
Countermeasure
• Check the wiring. (Refer to the Instruction Manual
(Connection).)
• Check the Pr.800 setting. (Refer to
• Set the speed limit value. (If speed limit value is not input, it
becomes 0 Hz by default and the motor does not run.)
• Check that the torque command sent from the controller is
correct.
• Set Pr.72 PWM frequency selection lower.
• Set Pr.826 Torque setting filter 1 higher.
• Re-calibrate C38 Terminal 4 bias command (torque/
magnetic flux), C39 Terminal 4 bias (torque/magnetic
flux), C40 Terminal 4 gain command (torque/magnetic
flux), C41 Terminal 4 gain (torque/magnetic flux). (Refer to
page 278.)
• Re-calibrate C38 and C39. (Refer to
• Set the acceleration/deceleration time shorter.
Alternatively, set "0" for the acceleration/deceleration time.
(Forward/reverse rotation speed limit at this time is the value
at a constant speed.)
page 86.)
page 278.)