Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Manual (Page 293)

9 Troubleshooting
9-28
9.3 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 outlined in bold in the table.
Problem Probable Cause Investigative Actions Corrective Actions
Servomotor Does
Not Start
The control power supply is not
ON. Check voltage between power sup-
ply terminals.
Correct the power circuit.
The main circuit power supply is
not ON. Check the voltage between power
supply terminals.
Correct the power circuit.
Wiring of I/O signal connector CN1
faulty or disconnected. Check if the connector CN1 is prop-
erly inserted and connected. Correct the connector CN1 connec-
tion.
Servomotor or encoder wiring dis-
connected.
Check the wiring. Correct the wiring.
Overloaded
Run under no load and check the
load status. Reduce load or replace with larger
capacity servomotor.
Setting for Pn50A, Pn50B and
Pn511 “Input Signal Selection” is
incorrect.
Check settings of parameters
Pn50A, Pn50B and Pn511.
Correct the settings for Pn50A,
Pn50B and Pn511 “Input Signal
Selection.”
Encoder type differs from parame-
ter setting (Pn002.2). Check setting of parameter
Pn002.2. Set parameter Pn002.2 to the
encoder type being used.
A servo ON command was not
input. Check the command sent from the
host controller.
Send a servo ON command.
A sensor ON command was not
input. Check the command sent from the
host controller. Send the command in the correct
sequence to the SERVOPACK.
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 or /HWBB2
input signal.
Set the /HWBB1 or /HWBB2 input
signal to ON.
When not using the safety function,
mount the safety function’s jumper
connector (provided as an acces-
sory) on the CN8.
A SERVOPACK fault occurred. – Replace the SERVOPACK.
Servomotor
Moves
Instantaneously,
and then Stops
Servomotor wiring is incorrect. Check the servomotor wiring. Correct the wiring.
Encoder wiring is incorrect. Check the encoder wiring. Correct the wiring.
Servomotor
Speed Unstable
Wiring connection to servomotor is
defective.
Check connections of main circuit
cable (phases-U, -V, and -W) and
encoder connectors.
Tighten any loose terminals or con-
nectors.
Servomotor
Rotates Without
Reference Input
A SERVOPACK fault occurred. – Replace the SERVOPACK.
Dynamic Brake
Does Not Operate
Setting for Pn001 is incorrect.
Check the setting of parameter
Pn001.0.
Correct the parameter setting.
DB resistor disconnected
Check if excessive moment of iner-
tia, motor overspeed, or DB fre-
quently activated occurred. Replace the SERVOPACK, and
lighten the load to avoid disconnec-
tion.
DB drive circuit fault –
There is a defective component in
the DB circuit. Replace the SER-
VOPACK.