Power unit: Load supply switched out

What does A30016 mean?

This alarm indicates that the DC link voltage is too low, causing the load supply to be switched out. The alarm value (r2124) displays the DC link voltage at the time of the trip. A common cause is the AC line supply not being switched on or being inadequate. If ignored, the drive will be unable to operate.

• Input AC line voltage drop below the minimum operating threshold (e.g., <340V for a 400V drive) due to supply issues.
• One or more input phases completely lost due to a blown fuse, tripped circuit breaker, or open feeder line upstream.
• Failure of the internal rectifier stage within the drive, preventing proper DC link voltage charging.
• Excessive load transients or regenerative braking causing DC link voltage sag beyond the drive's regulation capability.

Click steps to track your progress.

1. 1

   Measure the input AC line voltage at the drive's input terminals (L1, L2, L3) using a multimeter to confirm nominal voltage.

2. 2

   Verify the integrity of all upstream fuses, circuit breakers, and disconnect switches in the AC supply line.

3. 3

   Monitor the DC link voltage (r2124) during operation to observe any sag events or sustained low voltage.

4. 4

   Inspect the drive's input power terminals for loose connections, signs of overheating, or discoloration.

5. 5

   Temporarily reduce motor load (r0027) or reduce acceleration rates (P1120) to see if the DC link voltage stabilizes.