Troubleshooting In Torque Control - Mitsubishi Electric FR-E800 Instruction Manual

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 249
Pr.178 to Pr.189 (Input terminal function
Pr.800 Control method selectionpage 115
Pr.807 Speed limit selectionpage 171
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.
• The speed limit is operating.
(The 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 410
bias/gain)page 405
Countermeasure
• Check the wiring. (Refer to the Instruction Manual
(Connection).)
• Check the Pr.800 setting. (Refer to
• Set the speed limit value. (If the 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), C39 (Pr.932) Terminal 4 bias (torque), C40
(Pr.933) Terminal 4 gain command (torque), and C41
(Pr.933) Terminal 4 gain (torque). (Refer to
• Re-calibrate C38 (Pr.932) and C39 (Pr.932). (Refer to
405.)
• Set the acceleration/deceleration time shorter.
Alternatively, set "0" for the acceleration/deceleration time.
(The speed limit during acceleration/deceleration is
determined by the speed limit for constant speed.)
• Reset Pr.854 Excitation ratio to the initial value.
6.7 Troubleshooting in torque control
page 115.)
page 405.)
page
175
6. Torque Control
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