Mitsubishi Electronics FR-A740-0.4k to 500k ユーザーズマニュアル
422
Check first when you have a trouble
5.5.5
Motor rotates in the opposite direction
5.5.6
Speed greatly differs from the setting
5.5.7
Acceleration/deceleration is not smooth
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Main
Circuit
Phase sequence of output terminals U, V and W is
incorrect.
incorrect.
Connect phase sequence of the output cables (terminal
U, V, W) to the motor correctly.
U, V, W) to the motor correctly.
Input
signal
The start signals (forward rotation, reverse rotation) are
connected improperly.
connected improperly.
Check the wiring. (STF: forward rotation , STR: reverse
rotation)
rotation)
The polarity of the frequency command is negative
during the polarity reversible operation set by Pr. 73
Analog input selection.
during the polarity reversible operation set by Pr. 73
Analog input selection.
Check the polarity of the frequency command.
Input
signal
Parameter
setting
Torque command is negative during torque control
under vector control.
under vector control.
Check the torque command value.
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Input
signal
Frequency setting signal is incorrectly input.
Measure the input signal level.
—
The input signal lines are affected by external EMI.
Take countermeasures against EMI such as using
shielded wires for input signal lines.
shielded wires for input signal lines.
Parameter
Setting
Pr. 1, Pr. 2, Pr. 18, calibration parameter C2 to C7 settings
are improper.
are improper.
Check the settings of Pr. 1 Maximum frequency, Pr. 2
Minimum frequency, Pr. 18 High speed maximum frequency.
Minimum frequency, Pr. 18 High speed maximum frequency.
Check the calibration parameter C2 to C7 settings.
Pr. 31 to Pr. 36 (frequency jump) settings are improper.
Narrow down the range of frequency jump.
Load
Stall prevention (torque limit) function is activated due to
a heavy load.
a heavy load.
Reduce the load weight.
—
Parameter
Setting
Set Pr. 22 Stall prevention operation level (Torque limit level)
higher according to the load. (Setting Pr. 22 too large
may result in frequent overcurrent trip (E.OC ).)
higher according to the load. (Setting Pr. 22 too large
may result in frequent overcurrent trip (E.OC ).)
Motor
Check the capacities of the inverter and the motor.
—
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Parameter
Setting
Acceleration/deceleration time is too short.
Increase acceleration/deceleration time.
Torque boost (Pr. 0, Pr. 46, Pr. 112) setting is improper
under V/F control, so the stall prevention function is
activated.
under V/F control, so the stall prevention function is
activated.
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments to the setting. Deactivate stall
prevention.
0.5% increments to the setting. Deactivate stall
prevention.
The base frequency setting and the motor characteristic
does not match.
does not match.
For V/F control, set Pr. 3 Base frequency, Pr. 47 Second V/F
(base frequency), and Pr.113 Third V/F (base frequency).
(base frequency), and Pr.113 Third V/F (base frequency).
For vector control, set Pr.84 Rated motor frequency.
Regeneration avoidance operation is performed
If the frequency becomes unstable during regeneration
avoidance operation, decrease the setting of Pr. 886
Regeneration avoidance voltage gain.
avoidance operation, decrease the setting of Pr. 886
Regeneration avoidance voltage gain.
Load
Stall prevention (torque limit) function is activated due to
a heavy load.
a heavy load.
Reduce the load weight.
—
Parameter
Setting
Set Pr. 22 Stall prevention operation level (Torque limit level)
higher according to the load. (Setting Pr. 22 too large
may result in frequent overcurrent trip (E.OC ).)
higher according to the load. (Setting Pr. 22 too large
may result in frequent overcurrent trip (E.OC ).)
(100)
Motor
Check the capacities of the inverter and the motor.
—