DCU CEMF ALARM

What does 407 mean?

The Counter Electromotive Force (CEMF) of the motor exceeded 109% of the measured AC input voltage to the drive. This is a warning only and does not cause an automatic drive shutdown.

• 3 Phase Input AC Line Voltage drooped or is too low.
• CEMF on motor rises above AC input voltage.
• Motor field current set too high compared to desired motor voltage at top speed.
• Incorrect motor field control tuning preventing CEMF overshoot.

Click steps to track your progress.

1. 1

   Check and correct the 3 Phase Input AC Line Voltage if it is too low.

2. 2

   Verify weak field set point #49 against the desired motor voltage at top speed.

3. 3

   Check and correct motor field control tuning to prevent CEMF overshoot.

4. 4

   Review and verify settings for parameters #49, #50, #51, #52, #54, and #55.