DC-Link Error and Mains Supply Fault

What does PF DC Err mean?

This fault signifies a combined issue of a DC-link error and a problem with the mains supply. It suggests an unstable or incorrect input power condition affecting the drive's DC bus, which is fundamental to its operation. This can lead to erratic drive operation or severe damage to the rectifier and DC link capacitors if not resolved promptly.

• Unstable or fluctuating incoming mains voltage (sags, swells) coupled with degraded DC link capacitors.
• Intermittent phase loss on the input mains supply.
• Partial failure of the rectifier section causing unstable DC link voltage.
• Loose or high-resistance connections in the DC link bus bars or to the input rectifier.
• Heavy dynamic load causing large current draws that destabilize both mains and DC link.

Click steps to track your progress.

1. 1

   Measure incoming AC supply voltages at terminals L1, L2, L3 (phase-to-phase) and monitor for stability.

2. 2

   Inspect all input power connections and DC link bus bar connections for tightness and signs of overheating.

3. 3

   Check continuity of incoming fuses or circuit breakers.

4. 4

   Inspect DC link capacitors for bulging, leakage, or signs of overheating.

5. 5

   Use a power quality analyzer to log incoming mains voltage for prolonged periods to identify intermittent issues.