8 Troubleshooting
8-20
8.4
Troubleshooting Malfunction Based on Operation and
Conditions of the Servomotor
Troubleshooting for the malfunctions based on the operation and conditions of the servomotor is provided in
this section.
Be sure to turn OFF the servo system before troubleshooting items shown in bold lines in the table.
Problem
Probable Cause
Investigative Actions
Corrective Actions
Servomotor Does
Not Start
The control power supply is not
ON.
Check voltage between control
power input terminals.
Correct the wiring.
The main circuit power supply is
not ON.
Check the voltage between main
circuit power input terminals.
Correct the wiring.
Wiring of I/O signal connector CN1
is faulty or disconnected.
Check if the connector CN1 is prop-
erly inserted and connected.
Correct the connector CN1 connec-
tion.
Wiring for servomotor main circuit
cable or encoder cable is discon-
nected.
Check the wiring.
Correct the wiring.
Overloaded
Run under no load and check the
load status.
Reduce load or replace with larger
capacity servomotor.
Encoder type differs from parame-
ter setting (Pn002.2).
Check the settings for parameter
Pn002.2.
Set parameter Pn002.2 to the
encoder type being used.
Settings for the input signal selec-
tions (Pn50A, Pn50B and Pn511) is
incorrect.
Check the settings for parameters
Pn50A, Pn50B and Pn511.
Correct the settings for parameter
Pn50A, Pn50B and Pn511.
SV_ON command is not sent.
Check the command sent from the
host controller.
Send the SV_ON command.
SENS_ON command is not sent.
Check the command sent from the
host controller.
Send the command in the correct
SERVOPACK sequence.
The forward run prohibited (P-OT)
and reverse run prohibited (N-OT)
input signals are turned OFF.
Check P-OT or N-OT input signal.
Turn P-OT or N-OT input signal
ON.
A SERVOPACK fault occurred.
−
Replace the SERVOPACK.
Servomotor
Moves
Instantaneously,
and then Stops
Servomotor wiring is incorrect.
Check the wiring.
Correct the wiring.
Encoder wiring is incorrect.
Check the wiring.
Correct the wiring.
The SERVOPACK
suddenly entered
baseblock status
during servomotor
operation.
The main circuit power supply volt-
age is 13 V or lower.
Check voltage between main circuit
power input terminals during opera-
tion.
Set the power supply voltage to
within the specified range.
Increase the capacity of the main
circuit AC/DC power supply.
The fuse in the SERVOPACK is
blown.
−
Replace the SERVOPACK.
A SERVOPACK fault occurred.
−
A fault occurred in the SERVO-
PACK.
Replace the SERVOPACK.
Servomotor
Speed Unstable
Wiring connection to servomotor is
defective.
Check connections of power line
(phases U, V, and W) and encoder
connectors.
Tighten any loose terminals or con-
nectors and correct the wiring.
Servomotor
Rotates Without
Reference Input
A SERVOPACK fault occurred.
−
Replace the SERVOPACK.