12   Troubleshooting
12 - 44
AC Servomotors/Servo Drives 1S-series with Built-in EtherCAT® Communications User’s Manual (I586)
The Servomotor 
rotates in the reverse 
direction from the 
command.
The value set in Motor Rota-
tion Direction Selection 
(3000-01 hex) is incorrect.
Check the value of Motor 
Rotation Direction Selection.
Change the value of Motor 
Rotation Direction Selection.
The command given by the 
host controller is incorrect.
• The size of the absolute com-
mand is set incorrect.
• The polarity of an incremen-
tal command is set incorrect.
• Check the actual and target 
values.
• Check the rotation direction.
The Servomotor power cable is 
wired incorrectly.
Check the wiring. Wire correctly.
When the runaway 
detection function is 
enabled, the 
Servomotor rotates in 
the reverse direction 
from the command.
The value set in Motor Rota-
tion Direction Selection 
(3000-01 hex) is incorrect.
Check the value of Motor 
Rotation Direction Selection.
Change the value of Motor 
Rotation Direction Selection.
The command given by the 
host controller is incorrect.
• The size of the absolute com-
mand is set incorrect.
• The polarity of an incremen-
tal command is set incorrect.
• Check the actual and target 
values.
• Check the rotation direction.
The Servomotor power cable is 
wired incorrectly.
Check the wiring. Wire correctly.
The Servomotor power cable is 
wired incorrectly, and condi-
tions under which the runaway 
detection function cannot work 
are satisfied.
The holding brake 
does not work.
Power is supplied to the hold-
ing brake.
Check to see if power is sup-
plied to the holding brake.
• Check the Brake Interlock 
Output (BKIR) signal and the 
relay circuit.
• Check to see if the holding 
brake is worn down.
The applied timing for 
the holding brake is 
early.
The set value of Brake Inter-
lock Output (4610 hex) does 
not match the machine.
Review the setting of Brake 
Interlock Output (4610 hex).
Adjust Brake Interlock Out-
put (4610 hex).
Check the unit version of the 
Servo Drive. The default setting 
of Brake Interlock Output - 
Threshold Speed at Servo 
OFF (4610-03 hex) is large for 
the unit version Ver.1.4 or later.
Motor rotation is 
unstable.
The motor power cable or 
encoder cable is wired incor-
rectly.
Check the wiring of the motor 
power cable’s phases U, V, W 
and check the encoder cable’s 
wiring.
Wire correctly.
Low rigidity is causing vibration. Measure the vibration fre-
quency of the load.
Enable the damping control. 
Set the damping filter fre-
quency.
The load’s moment of inertia 
exceeds the Servo Drive’s 
allowable value.
Calculate the load inertia. • Check if manual tuning can 
achieve proper adjustment.
• Increase the Servomotor 
capacity.
Loose joint and/or large clear-
ance with the machine.
Check the joint with the 
machine.
Remove the joint looseness 
with the machine.
The load and gain do not 
match.
Check the response waveforms 
for speed and torque.
Perform the tuning again to sta-
bilize the rotation.
Symptom Probable cause Check items Measures