Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

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11. TROUBLESHOOTING
11.6 Trouble which does not trigger an alarm/warning
POINT
When the servo amplifier/servo motor/encoder malfunctions, the following
status may occur.
The following example shows possible causes which do not trigger alarm or warning. Refer to this section to
remove the cause of the error.
Description Check method Possible cause Action
The LED display
disappears. When the display is turned on by
disconnecting all connectors
except the power supply, check if
the disconnected wires are
shorted. The external I/O terminal is shorted. Review the wiring of I/O signals.
Check if the control circuit power
supply of the servo amplifier is off. The control circuit power supply is not
applied. Turn on the control circuit power.
Check if the voltage of the control
circuit power supply dropped. The voltage of the control circuit power
supply has dropped. Set the control circuit power supply
voltage within the rated range.
The servo motor
does not operate. Check if warning (A99) is
occurring. Forward rotation stroke end (LSP) and
reverse rotation stroke end (LSN) is not
switched on. Switch on the forward rotation stroke
end (LSP) and reverse rotation stroke
end (LSN).
Check the connection with servo
motor. The output terminals (U, V, W) of the
servo amplifier do not match the input
terminals (U, V, W) of the servo motor. Connect each phase of U, V and W
correctly.
Check if warning (AE9) is
occurring. The servo-on was turned on while the
main circuit power of servo amplifier is
off. Turn on the main circuit power.
Check if a servo alarm or warning
is occurring. A servo alarm occurred. Check the alarm content and remove
its cause.
Check the on/off states of servo-
on and reset. Servo-on is off. Turn on servo-on.
Reset is on. Turn off reset.
Check the setting of parameter
No.PA01 (control mode). The setting of parameter No.PA01
(control mode) is incorrect. Review the setting of parameter
No.PA01 (control mode).
Check if the generated torque
exceeds the torque limit value.
1. Check the "Instantaneous
torque" in the status display.
2. Check the torque ripple with
"Graph" command of "Monitor"
menu on MR Configurator.
1. The maximum torque is insufficient.
Servo capacity is short, or load is too
large.
1. Reduce the load by changing the
mass and shape of work.
2. Reduce the effective load ratio by
increasing acceleration/deceleration
time.
2. An unintended torque limit is enabled.
Or the setting of torque limit is 0
(Not generating torque).
(Set with parameter No.PA11, PA12,
PC35)
Review the torque limit setting.
Check the point table setting. The setting of point tables is incorrect. Review the point table setting.
Check if a machine part is
interfering. A machine part is interfering. Remove the interference of the
machine part.
For a servo motor with an
electromagnetic brake, check the
power supply of the
electromagnetic brake. The electromagnetic brake has not been
released. Turn on the power of electromagnetic
brake to release the brake.
Check the electronic gear setting. The setting of the electronic gear is
incorrect.
Set a proper value of the electronic
gear.