Undervoltage

What does 9 mean?

The DC-link voltage has decreased below the predefined limits. This is most often caused by an insufficient supply voltage, a component failure within the drive, a defective input fuse, or an external charge switch that is not properly closed. For 400-500Vac mains, a fault trips at 333Vdc (warning at 371Vdc); for 500-690Vac mains, a fault trips at 573Vdc (warning at 633Vdc). Subcodes S1 (DC-link too low during run), S2 (no data from power unit), and S3 (undervoltage control supervision) are available.

• DC bus voltage drops below the minimum operational threshold (P0301).
• Insufficient supply voltage (P0300).
• External load exceeding controller capacity.

Click steps to track your progress.

1. 1

   If a temporary supply voltage break occurred, reset the fault and restart the drive.

2. 2

   Measure the incoming AC supply voltage at the drive input terminals to verify it meets specified requirements.

3. 3

   Check all input fuses for continuity and proper rating.

4. 4

   Ensure any external charge switch is in the closed position.