PCU CEMF FAULT

What does 408 mean?

The Counter Electromotive Force (CEMF) of the motor exceeded 118% of the rated VAC input voltage to the drive. This fault causes a drive shutdown to prevent fuse blowing.

• Low 3 Phase Input AC Line Voltage.
• Incorrect motor field current setting or field regulator mis-operation causing excessive CEMF.
• Excessive drive speed overshoot.
• Poor motor field control dynamic tuning.

Click steps to track your progress.

1. 1

   Measure and correct the 3 Phase Input AC Line Voltage.

2. 2

   Check motor field current setting and field regulator operation.

3. 3

   Adjust velocity regulator to correct excessive drive speed overshoot.

4. 4

   Review and verify settings for parameters #49, #50, #51, #52, #54, and #55 to correct motor field control dynamic tuning.