Mitsubishi Electronics FR-V540-1.5K to 55K ユーザーズマニュアル

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47
Fine adjustment of gains for speed control
VE
CT
OR CONTROL
2
2.3.4
Troubleshooting
4
Long return time 
(response time)
Set the Pr. 821 value a little lower.
Decrease the value by half until just before an overshoot or the unstable phenomenon does 
not occur, and set about 0.8 to 0.9 of that value.
5
Overshoot or unstable 
phenomenon occurs.
Set the Pr. 821 value a little higher.
Double the value until just before an overshoot or the unstable phenomenon does not occur, 
and set about 0.8 to 0.9 of that value.
REMARKS
You can switch between PI control and P control under speed control using the X44 signal. (Refer to page 34.)
Phenomenon
Cause
Corrective Action
1
Motor does not rotate.
(1) The motor or encoder wiring is 
wrong.
(1) Check the wiring.
* Choose V/F control (Pr. 800 = 20) and check the 
rotation direction of the motor and the speed monitor 
output from the DA1 output terminal. For the FR-
V5RU, set "170V" for 3.7kW  or  less  and " 160V "  
for more in Pr. 19 "base frequency voltage", and set 
"50Hz" in Pr. 3 "base frequency".
When the forward rotation signal is 
input, the motor running in the 
 
counterclockwise direction as viewed 
from the motor shaft is normal. (If it runs 
in the clockwise direction, the phase 
sequence of the inverter secondary side 
wiring is incorrect.)
(2) The encoder specifications 
(jumper connector setting) are 
wrong.
(2) Check the encoder specifications.
Check the positions of the 5V/12V/24V/External 
and differential/complimentary jumper connectors.
(3) The encoder wiring is wrong.
(3) Check that FWD is displayed when running the 
motor in the counter-clockwise direction from 
outside during a stop of the inverter.
 
If REV is displayed, the encoder phase sequence 
is wrong. Perform the correct wiring or match the 
Pr. 852 "encoder rotation direction" setting.
(4) The Pr. 851 "number of encoder 
pulses" setting and the number of 
encoder  used are different.
(4) The motor will not run if the parameter setting is 
smaller than the number of encoder pulses used.
 
Set Pr. 851 "number of encoder pulses" correctly.
2
Motor does not run at 
correct speed.
(Speed command does 
not match actual speed)
(1) The speed command from the 
command device is incorrect.
 
The speed command is 
compounded with noise.
(1) Check that a correct speed command comes from 
the command device.
 
Decrease the PWM carrier frequency in Pr. 72.
(2) The speed command value does 
not match the inverter-recognized 
value.
(2) Readjust the speed command bias and gain in Pr. 
902, Pr. 903, Pr. 917, and Pr. 918.
(3) The number of encoder pulses 
setting is incorrect.
(3)
Check the setting of the number of encoder pulses 
in Pr. 851.
No.
Phenomenon/Condition
Adjustment Method
Pr. 852 
Setting
Relationship between the motor and 
encoder
0
1
(factory 
setting)
Forward rotation is clockwise rotation 
when viewed from A.
A
Encoder
CW
Forward rotation is counterclockwise rotation 
when viewed from A.
CCW
A
Encoder