Mitsubishi Electric FR-F800 Series Instruction Manual page 617

6.6.5 Motor rotates in the opposite direction
Check
point
Main The phase sequence of output terminals U, V
circuit and W is incorrect.
The start signals (STF and STR signals) are
connected improperly.
Input
The polarity of the frequency command is
signal
negative during the polarity reversible
operation set by Pr.73 Analog input
selection.
6.6.6 Speed greatly differs from the setting
Check
point
The frequency setting signal is incorrect.
Input
The input signal lines are affected by
signal
external EMI.
Pr.1 Maximum frequency, Pr.2 Minimum
frequency, Pr.18 High speed maximum
frequency, and the calibration parameter
Parameter
C2 to C7 settings are not appropriate.
setting
Pr.31 to Pr.36, and Pr.552 (frequency
jump) settings are not appropriate.
Load
Parameter Stall prevention function is activated due to
setting a heavy load.
Motor
6.6.7 Acceleration/deceleration is not smooth
Check
point
The acceleration/deceleration time is too
short.
The torque boost (Pr.0, Pr.46) setting is not
appropriate under V/F control, so the stall
prevention function is activated.
Parameter
setting
The base frequency does not match the
motor characteristics.
Regeneration avoidance operation is
performed.
Load
Parameter Stall prevention function is activated due to a
setting heavy load.
Motor
616
6. PROTECTIVE FUNCTIONS
6.6 Check first when you have a trouble
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Possible cause
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Possible cause
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Countermeasure
Connect the output side terminals (terminals U, V, and W)
correctly.
Check the connection. (STF: forward rotation, STR: reverse
rotation)
Check the polarity of the frequency command.
Countermeasure
Measure the input signal level.
Take countermeasures against EMI, such as using shielded wires
for input signal lines.
Check the settings of Pr.1, Pr.2, and Pr.18.
Check the calibration parameter C2 to C7 settings.
Narrow down the range of frequency jump.
Reduce the load weight.
Set Pr.22 Stall prevention operation level higher according to the
load. (If Pr.22 is set too high, an overcurrent trip (E.OC[]) is likely to
occur.)
Check the capacities of the inverter and the motor.
Countermeasure
Increase the acceleration/deceleration time.
Increase/decrease the Pr.0 Torque boost setting value by 0.5%
increments so that stall prevention does not occur.
Under V/F control, set Pr.3 Base frequency and Pr.47 Second V/
F (base frequency).
Under Advanced magnetic flux vector control or PM motor control,
set Pr.84 Rated motor frequency.
If the frequency becomes unstable during regeneration avoidance
operation, decrease the setting of Pr.886 Regeneration
avoidance voltage gain.
Reduce the load weight.
Set Pr.22 Stall prevention operation level higher according to the
load. (If Pr.22 is set too high, an overcurrent trip (E.OC[]) is likely to
occur.)
Check the capacities of the inverter and the motor.
Refer to
page
50
60, 563
349
Refer to
page
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93
287
357
289
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290
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Refer to
page
228
551
552
177
572
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290
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