12.4  Troubleshooting Based on the Operation and Conditions of the Servomotor 
12-54
Dynamic 
Brake Does 
Not Operate
The setting of Pn001 = 
n.X (Servo OFF or 
Alarm Group 1 Stopping 
Method) is not suitable.
Check the setting of 
Pn001 = n.X.
Set Pn001 = n.X 
correctly.
–
The dynamic brake resistor is 
disconnected.
Check the moment of 
inertia, motor speed, and 
dynamic brake frequency 
of use. If the moment of 
inertia, motor speed, or 
dynamic brake frequency 
of use is excessive, the 
dynamic brake resis-
tance may be discon-
nected.
Replace the SERVO-
PACK. To prevent dis-
connection, reduce the 
load.
–
There was a failure in the 
dynamic brake drive circuit.
–
There is a defective 
component in the 
dynamic brake circuit. 
Replace the SERVO-
PACK.
–
Continued from previous page.
Problem Possible Cause Confirmation Correction Reference