Trouble Which Does Not Trigger An Alarm/Warning - Mitsubishi Electric MELSERVO-J3 Series Instruction Manual

11. TROUBLESHOOTING

11.6 Trouble which does not trigger an alarm/warning

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
The LED display When the display is turned on by
disappears. disconnecting all connectors
except the power supply, check if
the disconnected wires are
shorted.
Check if the control circuit power
supply of the servo amplifier is off.
Check if the voltage of the control
circuit power supply dropped.
The servo motor Check if warning (A99) is
does not operate. occurring.
Check the connection with servo
motor.
Check if warning (AE9) is
occurring.
Check if a servo alarm or warning
is occurring.
Check the on/off states of servo-
on and reset.
Check 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.
Check the point table setting.
Check if a machine part is
interfering.
For a servo motor with an
electromagnetic brake, check the
power supply of the
electromagnetic brake.
Check the electronic gear setting.
POINT
When the servo amplifier/servo motor/encoder malfunctions, the following
status may occur.
Check method
The external I/O terminal is shorted.
The control circuit power supply is not
applied.
The voltage of the control circuit power
supply has dropped.
Forward rotation stroke end (LSP) and
reverse rotation stroke end (LSN) is not
switched on.
The output terminals (U, V, W) of the
servo amplifier do not match the input
terminals (U, V, W) of the servo motor.
The servo-on was turned on while the
main circuit power of servo amplifier is
off.
A servo alarm occurred.
Servo-on is off.
Reset is on.
The setting of parameter No.PA01
(control mode) is incorrect.
1. The maximum torque is insufficient.
Servo capacity is short, or load is too
large.
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)
The setting of point tables is incorrect.
A machine part is interfering.
The electromagnetic brake has not been
released.
The setting of the electronic gear is
incorrect.
Possible cause
11 - 20
Action
Review the wiring of I/O signals.
Turn on the control circuit power.
Set the control circuit power supply
voltage within the rated range.
Switch on the forward rotation stroke
end (LSP) and reverse rotation stroke
end (LSN).
Connect each phase of U, V and W
correctly.
Turn on the main circuit power.
Check the alarm content and remove
its cause.
Turn on servo-on.
Turn off reset.
Review the setting of parameter
No.PA01 (control mode).
1. Reduce the load by changing the
mass and shape of work.
2. Reduce the effective load ratio by
increasing acceleration/deceleration
time.
Review the torque limit setting.
Review the point table setting.
Remove the interference of the
machine part.
Turn on the power of electromagnetic
brake to release the brake.
Set a proper value of the electronic
gear.