Mitsubishi Electric MELSERVO-J3W Series, Instruction Manual

Page: 152 / 500

8. TROUBLESHOOTING
8 - 13
Alarm No.21 Name: Encoder normal communication error 2 Stop method: Corresponding axis stops
Alarm description Error is found in the encoder data.
Display Name Cause Checkpoint Finding Action
21.1 Encoder data
error
(1) Not reproduced. Use the encoder with
low loop gain. High acceleration rate is
detected in the encoder
because of oscillation and
other factors. Decrease the loop gain,
and check the
reproducibility of the error. Reproduced. Check
(2).
(2) Fault is generated from
the surrounding
environment.
Check for noise and other
factors. Problem found. Take countermeasure
according to the
cause.
No problem found. Check (3).
(3) Encoder is faulty. Error is not
reproduced. Replace the servo
motor. Replace the servo motor
and check the
reproducibility of the error. Error is reproduced.
Contact your local
sales office.
21.2 Encoder data
update error
(1) Encoder is faulty. Replace the servo motor
and check the
reproducibility of the error. Rotation motor. Replace the servo
motor.
Alarm No.24 Name: Main circuit error Stop method: All axes stop
Alarm description
Ground fault occurs at servo motor power cable of the servo amplifier.
Ground fault occurs at servo motor.
Display Name Cause Checkpoint Finding Action
24.1 (1) Servo amplifier is faulty. Appears. Replace the servo
amplifier. Check this alarm appears
even when power cable
(U, V and W) is
disconnected.
Does not appear. Check (2).
Ground fault
detected at
hardware
detection circuit
(2) Shorted. Replace the power
cable. Short or ground fault
occurs at servo motor
power cable. Check if only the power
cable is shorted (among
U, V, W and ).
Not shorted. Check (3).
(3) Ground fault occurs at
servo motor.
Shorted. Replace the servo
motor. Disconnect power cables
on motor side, and check
insulation of the motor
(among U, V, W and ).
Not shorted. Check (4).
(4) In contact. Modify the wiring. Power input cable and
servo motor power cable
are shorted. Shut off the power, and
check if power input cable
and servo motor power
cable are in contact.
Not in contact. Check (5).
(5) Fault is generated from
the surrounding
environment.
Check for noise and other
factors. Problem found. Take countermeasure
according to the
cause.
24.2 (1) Servo amplifier is faulty. Examine checkpoints described in the alarm display "24.1".
(2) Short or ground fault
occurs at servo motor
power cable.
Ground fault
detected at
software
detection function
(3) Ground fault occurs at
servo motor.
(4) Power input cable and
servo motor power cable
are shorted.
(5) Fault is generated from
the surrounding
environment.