• The RT signal is a second function selection signal which also enables other second functions. (Refer to
• The RT signal is assigned to terminal RT in the initial status. Set "3" in one of Pr.178 to Pr.189 (Input terminal function
selection) to assign the RT signal to another terminal.
Adjust if any of phenomena such as unusual vibration, noise, current or overcurrent is produced by the motor or machinery.
Change the Pr.824 setting while checking the conditions.
If it cannot be adjusted well, change the Pr.825 setting, and perform step 1 again.
Set Pr.824 lower and Pr.825 longer. First, lower Pr.824 and then check of there is still any abnormal vibration, noise or
current from the motor If it still requires improvement, make Pr.825 longer.
Lower the setting by 10% each time and set a value that is approximately 80 to 90% of the setting
immediately before the abnormal noise or current improves.
If set too low, current ripple is produced and produces a sound from the motor that synchronizes with it.
Lengthen the current setting by doubling it each time and set a value that is approximately 80 to 90% of the
setting value, immediately before abnormal noise or current is improved.
If set too long, current ripple is produced and produces a sound from the motor that synchronizes with it.
Troubleshooting in torque control
Torque control does not
When a small torque
command is given, the
motor rotates in a
direction opposite to the
Torque control cannot
operate normally during
The motor vibrates.
Output torque is
nonlinear for the torque
Parameters referred to
Pr.72 PWM frequency
Pr.178 to Pr.189 (Input terminal function
Pr.800 Control method
Pr.807 Speed limit
• There is incorrect phase sequence
between the motor wiring and
• Pr.800 Control method selection
is not appropriate.
• The speed limit value has not been
• Torque command varies.
• The torque command and the torque
recognized by the inverter are
• Torque fluctuation due to motor
• The option to be used and
parameter settings do not match.
• Torque offset calibration is
• 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 or 2".)
5.4 Torque control under Real sensorless vector control and Vector control
• Check the wiring. (Refer to
• 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
• Set Pr.72 PWM frequency selection lower.
• Set Pr.826 Speed setting filter 1 higher.
• Re-calibrate the settings of C16 Terminal 1 bias command
(torque), C17 Terminal 1 bias (torque), C18 Terminal 1
gain command (torque), C19 Terminal 1 gain (torque)
• Select the magnetic flux observer by Pr.95 Online auto
tuning selection. (Refer to
• Correctly set Pr.862 Encoder option selection according to
the option to be used. (Refer to
• Re-calibrate C16 and C17. (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.)
Return Pr.854 Excitation ratio to the initial value.