DC Under Voltage

What does F47 mean?

This Automatic Fault occurs as an immediate DC under-voltage shutdown if the DC voltage drops below 32 V. The fault automatically clears, and the inverter restarts when the DC voltage reaches V+4 V (36V), pointing to potential battery or load issues.

• Discharged or deeply discharged battery bank (e.g., voltage below 32V for a 48V nominal system).
• High current draw from a load exceeding the battery's or DC source's capacity, causing voltage sag.
• Faulty DC power source (e.g., solar array not generating sufficient voltage, rectifier failure).
• Excessive resistance in the DC cabling (too thin, long run) or loose/corroded connections.
• Incorrectly configured low DC voltage disconnect threshold (e.g., Parameter P2-10 set too high).

Click steps to track your progress.

1. 1

   Measure the DC voltage directly at the inverter's DC input terminals (e.g., B+, B-) using a calibrated multimeter.

2. 2

   Verify the state of charge of the battery bank using a battery monitor or by measuring individual cell voltages.

3. 3

   Inspect all DC input cabling from the source (battery, solar array) to the inverter for proper gauge, secure connections, and absence of corrosion.

4. 4

   Monitor the DC current draw from the inverter (e.g., Parameter P2-01) and compare it to the battery bank's continuous discharge rating.

5. 5

   Review and adjust the DC under-voltage shutdown threshold (e.g., Parameter P2-10) to match the battery manufacturer's specifications.