SMA STP 33-US-41 - Page 63

6 Troubleshooting
SMA Solar Technology AG
User Manual STP33-62-US-41-BA-en-11 63
4. If a definite ground fault cannot be measured and the message is still displayed, measure the
insulation resistance.
5. Reconnect the strings without ground faults to the inverter and recommission the inverter (see
inverter installation inverter).
Location of the ground fault
The example shows a ground fault between the second and third PV module.
+
100 V 100 V 100 V 100 V 100 V
V = 200 V
1
V = 300 V
2
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.
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Figure 4: Schematic diagram of the measurement