Mitsubishi Electric FR-A700 Instruction Manual page 305

Parameter
Adjustment procedure
Make adjustment when any of such phenomena as unusual motor and machine vibration/noise/
current and overcurrent has occurred.
Check the conditions and simultaneously change the Pr. 824 value.
If you cannot make proper adjustment, change the Pr. 825 value and repeat step
Adjustment Method
Set Pr. 824 a little lower and Pr. 825 a little higher. First lower Pr. 824 and check the motor for unusual vibration/
noise and overcurrent. If the problem still persists, increase Pr. 825.
Pr. 824
Pr. 825
Tab. 6-23: Adjustment method for setting parameter 824 and 825
Troubleshooting (Torque)
Phenomenon
Torque control is not exer-
1
cised normally.
Tab. 6-23: Troubleshooting during torque control (1)
FR-A700 EC
Torque control by real sensorless vector control, vector control
Decrease the value 10% by 10% until just before unusual noise and current are improved, and
set about 0.8 to 0.9 of that value.
Note that a too low value will produce current ripples, causing the motor to generate sound syn-
chronizing the cycle of current ripples.
Increase the current value double by double until just before an unusual noise and current does
not occur, and set about 0.8 to 0.9 of that value.
Note that taking a too long time will produce current ripples, causing the motor to generate
sound synchronizing the cycle of current ripples.
Cause
(1) The phase sequence of the
motor or encoder wiring is
wrong.
(2) The Pr. 800 "Control method
selection" setting is improper.
(3) The speed limit value is not
input.
(4) The torque command varies.
(5)The torque command does not
match the inverter-recognized
value.
(6) Torque variation due to the
change in the motor tempera-
ture.
Countermeasures
(1) Check the wiring. (Refer to section 3.2.)
(2) Check the Pr. 800 setting.
(Refer to section 6.2.2.)
(3) Set the speed limit value. (If the speed limit
value is not input, the motor will not rotate
since the speed limit value is regarded as
0Hz.)
(4)-1 Check that the command device gives a
correct torque command.
(4)-2 Decrease Pr. 72 "PWM frequency
selection".
(4)-3 Increase Pr. 826 "Torque setting
filter 1".
(5) Recalibrate C16 "Terminal 1 bias com-
mand (torque/magnetic flux)", C17 "Termi-
nal 1 bias (torque/magnetic flux)", C18
"Terminal 1 gain command (torque/mag-
netic flux)", C19 "Terminal 1 gain (torque/
magnetic flux)". (Refer to section 6.20.6.)
(6) Select magnetic flux observer by setting Pr.
95 "Online auto tuning selection". (Refer to
section 6.12.4).
.
6 - 125