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

Page: 393 / 1218

Parameters Position control under vector control and PM sensorless vector control
FR-A800 5 - 191
5.5.10 Troubleshooting in position control
Condition Cause Countermeasure
1
The motor does not
rotate.
There is incorrect phase
sequence between the motor
wiring and encoder wiring.
Check the wiring. (Refer to page 2-77.)
Control mode selection setting
Pr. 800 "Control method
selection" is not appropriate.
Check the Pr. 800 setting. (Refer to page 5-61.)
No servo ON or stroke end signals
(STF/STR) are input.
Check if a signal is properly input.
A command pulse or position
pulse sign (NP) is not correctly
input.
앫
Check if the command pulse is properly input.
(check the accumulated value for command pulses
in Pr. 430 "Pulse monitor selection").
앫
Check the command pulse type in Pr. 428
"Command pulse selection".
앫
Check that the position pulse sign (NP) is assigned
to an input terminal. (inverter pulse input)
The setting in Pr. 419 "Position
command source selection"
(position command source
selection) is not correct.
Check the position command source selection in
Pr. 419.
When simple position control by
a point table (Pr. 419 = "0") is
used, the position feed length set
by Pr. 465 to Pr. 494 is not correct.
Check the position feed length in Pr. 465 to Pr. 494.
The option to be used and
parameter settings do not match.
Correctly set Pr. 862 "Encoder option selection"
according to the option to be used.
(Refer to page 5-69)
2
The position is
unfavorably shifted.
A command pulse is not correctly
input.
앫
Check the command pulse type in Pr. 428
"Command pulse selection".
앫
Check if the command pulse is properly input.
(check the accumulated value of command pulses
in Pr. 430)
앫
Check that the position pulse sign (NP) is assigned
to an input terminal. (inverter pulse input)
The command is affected by
noise. Noise is superpositioned
on the encoder feedback signals.
앫
Set Pr. 72 "PWM frequency selection" lower.
앫
Change the earthing (grounding) position of the
shielded cable. Alternatively, do not connect it.
3
Hunting occurs in the
motor or the machine.
Position loop gain is too high. Set Pr. 422 "Position control gain" lower.
Speed loop gain is too high.
앫
Perform easy gain tuning.
앫
Set Pr. 820 "Speed control P gain 1" lower and
Pr. 821 "Speed control integral time 1" higher.
4
Machine movement is
unstable. Acceleration/deceleration time
settings are affecting adversely. Set Pr. 7 "Acceleration time" and Pr. 8 "Deceleration
time" lower.
Tab. 5-71: Troubleshooting
Vector Vector Vector PM PM PM