DCU CEMF FAULT

What does 407 mean?

This fault indicates that the Counter-Electromotive Force (CEMF) of the motor has exceeded 109% of the measured AC input voltage supplied to the DSD 412 drive. This is a warning and does not cause an automatic drive shutdown.

• The 3 Phase Input AC Line Voltage has drooped significantly or is too low.
• Motor CEMF rises unexpectedly above the VAC input voltage.
• Motor field current is set too high, leading to excessive CEMF production.

Click steps to track your progress.

1. 1

   Check the 3 Phase Input AC Line Voltage for droops or excessively low levels.

2. 2

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

3. 3

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

4. 4

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