Ground Fault Message Displayed — Ground Fault in PV System

What does Ground Fault Message mean?

The SMA SUNNY BOY SB30-50-1AV-40 Inverter displays a message indicating a ground fault within the photovoltaic system. This means there is an unintended electrical connection between a live part of the PV system and the ground, which needs to be identified and resolved for safe and optimal operation.

• Damage to PV module insulation or wiring.
• Damaged or faulty wiring in the PV array.
• Moisture ingress into connectors or junction boxes.
• Incorrect wiring during installation.

Click steps to track your progress.

1. 1

   For your safety, disconnect the inverter from all voltage sources following the procedures in Section 10 of your manual.

2. 2

   Measure the voltage for each PV string: between positive and ground (PE), negative and ground (PE), and positive and negative terminals.

3. 3

   If the sum of the two voltages to ground approximately equals the voltage between positive and negative, a ground fault is present.

4. 4

   If the voltage test is inconclusive but the ground fault message persists, perform an insulation resistance measurement as described in the manual.

5. 5

   Once the ground fault is located and repaired, reconnect strings without faults and recommission the inverter.