Mitsubishi Electric MELSERVO MR-J4-B-RJ Series, Instruction Manual

Page: 41 / 174

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
1 - 34
Alarm No.: 24 Name: Main circuit error
Alarm content
A ground fault occurred on the servo motor power lines.
A ground fault occurred at the servo motor.
Power supply voltage for inverter circuit control is low. (Only for MR-J4W2-0303B6)
Detail
No.
Detail name Cause Check method Check result Action Target
24.2 Ground fault
detected by
software
detection
function
(1) For MR-J4W2-0303B6,
the servo-on command
was inputted when the
control circuit power
supply voltage was
below 20 V.
Check the control
circuit power supply
voltage when the
servo-on command
was inputted. The control circuit
power supply
voltage was below
20 V. Input the servo-on
command after the
control circuit power
supply voltage
reaches 20 V or
higher. [WB]
The control circuit
power supply voltage
was 20 V or higher. Check (2).
(2) The servo amplifier is
malfunctioning.
Disconnect the servo
motor power cable
(U/V/W), and check if
the alarm occurs. It occurs. Replace the servo
amplifier. [A]
[B]
[WB]
[RJ010]
[GF]
It does not occur. Check (3).
(3) A ground fault or short
occurred at the servo
motor power cable.
Check if only the
servo motor power
cable is shorted. It is shorted. Replace the servo
motor power cable.
It is not shorted. Check (4).
(4) A ground fault occurred
at the servo motor.
Disconnect the servo
motor power cables
on motor side, and
check insulation
between phases
(U/V/W/ ). It is shorted. Replace the servo
motor.
It is not shorted. Check (5).
(5) The main circuit power
supply cable and servo
motor power cable
were shorted.
Shut off the power,
and check if the main
circuit power supply
cable and servo
motor power cable
are in contact. They are in contact. Correct the wiring.
They are not in
contact. Check (6).
(6) Something near the
device caused it.
Check the noise,
ambient temperature,
etc. It has a failure. Take
countermeasures
against its cause.