Troubleshooting In Torque Control - Mitsubishi Electric 800 Series Instruction Manual (Function

6.7

Troubleshooting in torque control

Sensorless Sensorless Sensorless Vector Vector Vector
No. 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.
Output torque is
4 nonlinear for the torque
command.
Parameters referred to
Pr.72 PWM frequency selectionpage 221
Pr.178 to Pr.189 (Input terminal function
Pr.800 Control method selectionpage 104
Pr.807 Speed limit selectionpage 153
C38 (Pr.932) to C41 (Pr.933) (torque setting voltage (current)
Possible cause
• There is incorrect phase sequence
between the motor wiring and
encoder wiring.
• 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".)
• Torque shortage.
selection)page 368
bias/gain)page 363
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 (Pr.932) Terminal 4 bias command
(torque/magnetic flux), C39 (Pr.932) Terminal 4 bias
(torque/magnetic flux), C40 (Pr.933) Terminal 4 gain
command (torque/magnetic flux), and C41 (Pr.933)
Terminal 4 gain (torque/magnetic flux). (Refer to
363.)
• Re-calibrate C38 (Pr.932) and C39 (Pr.932). (Refer to
363.)
• 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.)
• Reset Pr.854 Excitation ratio to the initial value.
6.7 Troubleshooting in torque control
page 104.)
page
page
157
6. Torque Control
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