Troubleshooting In Position Control - Mitsubishi Electric FR-E800 Instruction Manual

7.11

Troubleshooting in position control

Vector Vector Vector PM PM PM
Condition
The motor does not rotate.
The position is unfavorably
shifted.
Hunting occurs in the motor or
the machine.
Machine movement is
unstable.
The control method/mode
cannot be changed.
Possible cause
There is incorrect phase sequence
between the motor wiring and encoder
wiring.
The setting of Pr.800 Control method
selection is not appropriate.
The LX signal or the STF/STR signal is not
input.
The X87 signal, LSP signal, or LSN signal
is input (normally open input), or the PU
stop signal is input.
When simple position control by point
tables is used, the position feed length set
by Pr.465 to Pr.478 is not correct.
The command is affected by noise. Noise
is superpositioned on the encoder
feedback signals.
The electronic gear settings in Pr.420 and
Pr.421 are incorrect.
Position loop gain is too high.
Speed loop gain is too high.
Acceleration/deceleration time settings are
affecting adversely.
The LSP/LSN signal is input (normally
open input).
Countermeasure
Check the wiring. (Refer to the Instruction Manual
(Connection).)
Check the Pr.800 setting. (Refer to
Check that the signals are properly input.
Check if the signals are input.
Check the position feed length in Pr.465 to Pr.478.
Set a smaller value in Pr.72 PWM frequency selection.
Change the earthing (grounding) position of the shielded cable.
Alternatively, do not connect it.
Check the settings of Pr.420 and Pr.421.
Set a smaller value in Pr.422 Position control gain.
Set a smaller value in Pr.820 Speed control P gain 1 and a
larger value in Pr.821 Speed control integral time 1.
Shorten the acceleration/deceleration time (setting values in
Pr.7, Pr.8, Pr.1222, Pr.1223, Pr.1225 to Pr.1227, Pr.1229 to
Pr.1231, Pr.1233 to Pr.1235, Pr.1237 to Pr.1239, Pr.1241 to
Pr.1243, Pr.1245 to Pr.1247, Pr.1249).
Check if the signal is input.
7.11 Troubleshooting in position control
page 115.)
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