PCU LOOP FAULT

What does 900 mean?

The contactor failed to close or opened unexpectedly, or the motor voltage exceeded 30% of the rated motor voltage (parameter #7) during Self-Tune #997. This sets the Severe Fault flag, forces the DSD 412 current reference to zero, and shuts down the drive.

• Faulty contactor auxiliary feedback circuit connection to terminal TB1-7.
• Improper operation or failure of the contactor or LPR (Line Power Relay) coils.
• Loss of power supply to the LPR from terminal TB3-5.
• Internal failure of the A4 Power Supply PCB.

Click steps to track your progress.

1. 1

   Check the contactor auxiliary feedback circuit connected to terminal TB1-7.

2. 2

   Inspect the contactor and LPR coils for proper operation and continuity.

3. 3

   Measure the voltage supply to the LPR at terminal TB3-5; if power is absent, replace the A4 Power Supply PCB.

4. 4

   Conduct Self-Tune #997 again, observing motor voltage and contactor operation.