The Motor Current Is Too Large; Speed Does Not Accelerate - Mitsubishi Electric FR-CS82S-025 Instruction Manual

6.6.9

The motor current is too large

Check Possible cause
point
Torque boost (Pr.0) setting is improper
under the V/F control, so the stall
prevention function is activated.
The V/F pattern is not appropriate when V/
F control is performed. (Pr.3, Pr.19)
Paramete
r setting
The stall prevention function is activated
due to a heavy load.
Auto tuning is not performed under
General-purpose magnetic flux vector
control.

6.6.10 Speed does not accelerate

Check Possible cause
point
The start command or frequency
command is chattering.
The wiring length is too long for the analog
Input
frequency command, causing a voltage
signal
(current) drop.
The input signal lines are affected by
external EMI.
Pr.1 Maximum frequency, Pr.2 Minimum
frequency, Pr.18 High speed maximum
frequency, and calibration parameters
C2 to C7 settings are not appropriate.
The maximum voltage (current) input
value is not set during the External
operation. (Pr.125, Pr.126, Pr.18)
Torque boost (Pr.0) setting is improper
under the V/F control, so the stall
prevention function is activated.
The V/F pattern is not appropriate when V/
Paramete
F control is performed. (Pr.3, Pr.19)
r setting
The stall prevention function is activated
due to a heavy load.
Auto tuning is not performed under
General-purpose magnetic flux vector
control.
During PID control, the output frequency is automatically controlled so that the measured value equals the set
point.
Countermeasure
Increase/decrease the Pr.0 Torque boost setting value by 0.5%
increments so that stall prevention does not occur.
Set rated frequency of the motor to Pr.3 Base frequency.
Use Pr.19 Base frequency voltage to set the base voltage (e.g. rated
motor voltage).
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.
Perform offline auto tuning
Countermeasure
Check if the start command and the frequency command are correct. —
Perform the bias and gain calibration for the analog input.
Take countermeasures against EMI, such as using shielded wires for
input signal lines.
Check the settings of Pr.1 and Pr.2. To operate at 120Hz or higher,
set Pr.18 High speed maximum frequency.
Check the calibration parameter C2 to C7 settings.
Check the Pr.125 Terminal 2 frequency setting gain frequency and
Pr.126 Terminal 4 frequency setting gain frequency settings.
To operate at 120 Hz or higher, set Pr.18.
Increase/decrease the Pr.0 Torque boost setting value by 0.5%
increments so that stall prevention does not occur.
Set rated frequency of the motor to Pr.3 Base frequency. Use Pr.19
Base frequency voltage to set the base voltage (e.g. rated motor
voltage).
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.
Perform offline auto tuning
Refer to
page
193
194
119
—
147
Refer to
page
134
50
117
134
117,
193
194
—
119
—
147
152
6. PROTECTIVE FUNCTIONS
6.6 Check first when you have a trouble
1
2
3
5
6
7
8
9
10
134
225