Power unit: Line asymmetry

What does A30057 mean?

Frequencies detected on the DC link voltage suggest line asymmetry or the failure of a line or motor phase. If this alarm persists, it will eventually trigger fault F30011 after a specific duration. This condition causes imbalanced currents, increased losses, and premature component wear, and if unresolved, will lead to a drive trip, interrupting operation.

• Loss of one phase in the three-phase AC input supply (e.g., blown fuse, open circuit breaker upstream of the drive).
• Significant voltage imbalance between the input phases (e.g., >5% deviation) due to utility issues or unequal loading on the grid.
• Faulty or damaged input line reactor, leading to improper current distribution or voltage drop across phases.
• Loose or corroded connections at the main power input terminals (e.g., L1, L2, L3) of the drive.

Click steps to track your progress.

1. 1

   Measure the line-to-line voltages (L1-L2, L2-L3, L3-L1) at the drive's input terminals (e.g., X10/X100 terminals) using a multimeter.

2. 2

   Check all input fuses and circuit breakers upstream of the drive for continuity and proper function.

3. 3

   Inspect the input wiring for loose connections or damaged conductors at the main terminals.

4. 4

   Verify the line reactor's inductance and inspect for visible damage or overheating if present in the input circuit.

5. 5

   Monitor parameter r0025 for incoming line voltage values to confirm stability and balance.