Mitsubishi Electric MELSEC-Q QD75M User Manual page 741

15 TROUBLESHOOTING
LED indicator
Classifica
of servo
Error
tion of
amplifier
code
errors
IFU
2022 FA.1C
2023
FA.1D
2024 FA.1E
2020 —
Servo
amplifier
errors
2024 —
2025
—
Error name
DRU
There is error in communication
Base unit bus
— between interface unit and drive
error 1
unit.
There is error in communication
Base unit bus
between interface unit and drive
—
error 2
unit.
Servo amplifier Drive unit came off the base unit
—
mounting error after initialization.
Communication error occurred
@A.20# Encoder error 2
between encoder and drive unit.
Motor output
Servomotor output (U, V, W
@A.24# side ground
phase) ground fault.
fault
Absolute position data in error.
Absolute
@A.25#
position lost
Power was switched on for the
first time in the absolute position
detection system.
Description
15 - 78
MELSEC-Q
Cause
Interface unit connection fault.
Interface unit failure.
Base unit failure.
Drive unit connection fault.
Drive unit failure.
Base unit failure.
Drive unit connection fault.
Base unit failure.
Faulty parts in servo amplifier.
The encoder connecter is
disconnected.
Encoder fault.
Encoder cable faulty. (Wire
breakage or shorted)
Power input wires and servo motor
output wires are in contact at CNP2.
Sheathes of servo motor power
cables deteriorated, resulting in
ground fault.
Main circuit of drive unit failed.
Battery unit voltage low.
Battery cable or battery fault.
Super capacitor of the absolute
position encoder is not charged.