8 Troubleshooting
8-28
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.
Problem
Probable Cause
Investigative Actions
Corrective Actions
Servomotor Does
Not Start
The control power supply is not
ON.
Check voltage between control
power terminals.
Turn OFF the servo system. Correct
the wiring so that the control power
supply turns ON.
The main circuit power supply is
not ON.
Check the voltage between main
circuit power terminals.
Turn OFF the servo system. Correct
the wiring so that the main circuit
power supply turns ON.
Wiring of I/O signal connector CN1
is faulty or disconnected.
Turn OFF the servo system. Check
if the connector CN1 is properly
inserted and connected.
Correct the connector CN1 connec-
tion.
Wiring for servomotor main circuit
cable or encoder cable is discon-
nected.
Check the wiring.
Turn OFF the servo system. Correct
the wiring.
Overloaded
Run under no load and check the
load status.
Turn OFF the servo system. 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 commands to the multi-
winding drive unit in the correct
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.
The safety input signal (/HWBB1 or
/HWBB2) remains OFF.
Check the /HWBB1 and /HWBB2
input signal.
Set the /HWBB1 and /HWBB2
input signal to ON.
When not using the safety function,
mount the safety function jumper
connector (provided as an acces-
sory) on the CN8.
The brake is not released.
Check the operation of the brake.
Release the brake.
A fault occurred in the SERVO-
PACK or converter.
−
Turn OFF the servo system.
Replace the SERVOPACK or con-
verter.
Servomotor
Moves
Instantaneously,
and then Stops
Servomotor wiring is incorrect.
Turn OFF the servo system. Check
the wiring.
Correct the wiring.
Encoder wiring is incorrect.
Turn OFF the servo system. Check
the wiring.
Correct the wiring.
Servomotor
Speed Unstable
Wiring connection to servomotor is
defective.
Turn OFF the servo system. Check
connections of power line (phases
U, V, and W) and encoder connec-
tors.
Tighten any loose terminals or con-
nectors and correct the wiring.
Servomotor
Rotates Without
Reference Input
A fault occurred in the multi-wind-
ing drive unit or SERVOPACK.
−
Turn OFF the servo system.
Replace the multi-winding drive
unit or SERVOPACK.
