SMA Solar Technology SUNNY BOY 3.0, Operating Manual, Page: 82 / 100

Example: Location of the ground fault
The example shows a ground fault between the second and third PV module.
3. If a definite ground fault cannot be measured and the message is still displayed, measure the
insulation resistance.
4. Reconnect the strings without ground faults to the inverter and recommission the inverter.
Test by Measuring the Insulation Resistance
If the voltage measurement does not provide sufficient evidence of a ground fault, the insulation
resistance measurement can provide more exact results.
Figure 12: Schematic diagram of the measurement
12 Troubleshooting SMA Solar Technology AG
Operating Manual SB30-50-1AV-40-BE-en-10 82