Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 1088 / 1218

Check first when you have a trouble Protective functions
6 - 48
6.6.12 Speed does not accelerate
Check
points
Possible cause Countermeasure
Refer to
page
Input
signal
Start command and frequency command
are chattering. Check if the start command and the frequency
command are correct.
⎯
The wiring length used for analog
frequency command is too long, and it is
causing a voltage (current) drop.
Perform Analog input bias/gain calibration. 5-418
The input signal lines are affected by
external EMI. Take countermeasures against EMI, such as
using shielded wires for input signal lines.
3-6
Parameter
setting
Pr. 1 "Maximum frequency", Pr. 2 "Minimum
frequency", Pr. 18 "High speed maximum
frequency", and calibration parameters C2
to C7 settings are improper.
Check the settings of Pr. 1 and Pr. 2 and set
Pr. 18.
5-321
Check the calibration parameters C2 to C7
settings.
5-418
The maximum voltage (current) input value
is not set during the External operation.
(Pr. 125, Pr. 126, Pr. 18)
Check the settings of Pr. 125 "Terminal 2
frequency setting gain frequency" and Pr. 126
"Terminal 4 frequency setting gain frequency".
To operate at 120 Hz or higher, set Pr. 18 "High
speed maximum frequency".
5-321,
5-418
Torque boost (Pr. 0, Pr. 46, Pr. 112) setting is
improper under V/F control, so the stall
prevention function is activated. Increase/decrease the Pr. 0 "Torque boost"
setting value by 0.5% increments so that stall
prevention does not occur.
5-688
V/F pattern is improper when V/F control is
performed.
(Pr. 3, Pr. 14, Pr. 19)
Set rated frequency of the motor to Pr. 3 "Base
frequency".
Use Pr. 19 "Base frequency voltage" to set the
base voltage (for example, rated motor
voltage).
5-690
Change Pr. 14 "Load pattern selection"
according to the load characteristic.
5-692
Stall prevention (torque limit) function is
activated due to a heavy load.
Reduce the load weight.
⎯
Set Pr. 22 "Stall prevention operation level
(torque limit level)" higher according to the
load. (If Pr. 22 is set too high, an overcurrent trip
(E.OC
첸
) is likely to occur.)
5-90,
5-325
Check the capacities of the inverter and the
motor.
⎯
Auto tuning is not performed under
Advanced magnetic flux vector control, Real
sensorless vector control, or vector control.
Perform offline auto tuning. 5-72
The setting of pulse train input is improper.
Check the specification of the pulse generator
(open collector output or complementary
output) and check the adjustment of the pulse
train and frequency (Pr. 385 "Frequency for zero
input pulse" and Pr. 386 "Frequency for
maximum input pulse").
5-292
During PID control, output frequency is automatically controlled to make measured value =
set point.
5-543
Main
circuit Brake resistor is connected across terminals
P/+ and P1 or across P1 and PR by mistake. Connect an optional brake resistor (FR-ABR)
across terminals P/+ and PR.
2-87