SMA 20000TL Service Manual - Manual (Page 28)

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 (see
Section 11, page 34).
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 1: Schematic diagram of the measurement
8 Checking the PV System for Ground Faults SMA Solar Technology AG
Service Manual for Installers STP20-25TL-SG-en-11 28