Infeed: Line currents not symmetrical

What does 206207 mean?

The asymmetry of line currents in the infeed is too high, most likely due to a failure in one of the line phases. This imbalance can lead to improper operation of the infeed unit and potentially damage components if not resolved. It indicates an issue with the quality or integrity of the incoming power supply.

• Failure of one or more phases of the incoming AC supply (e.g., blown fuse, open circuit breaker upstream).
• Imbalance in the grid supply voltage, leading to unequal currents in the infeed phases.
• Faulty power semiconductor (e.g., IGBT, diode) in one leg of the infeed rectifier/inverter bridge.
• Loose or corroded connection on one of the input phases (L1, L2, L3) to the infeed unit terminals.
• Malfunctioning current sensor (e.g., CT) for one of the phases within the infeed module.

Click steps to track your progress.

1. 1

   Measure the incoming line voltages (L1-L2, L2-L3, L3-L1) at the infeed unit's input terminals using a multimeter.

2. 2

   Check all fuses and circuit breakers upstream of the infeed unit for continuity and proper operation.

3. 3

   Use a clamp meter to measure the individual phase currents (r0067[0], r0067[1], r0067[2]) on the input lines to the infeed module.

4. 4

   Inspect input terminals (e.g., X1, X3) on the infeed unit for loose connections or signs of overheating.

5. 5

   If voltage and connections are good, perform a power semiconductor test (e.g., diode check) on the infeed bridge, or replace the infeed unit.