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
selectionpage 221
Pr.178 to Pr.189 (Input terminal function
Pr.800 Control method
selectionpage 104
Pr.807 Speed limit
selectionpage 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
1
2
3
4
5
6
7
8
9
10