Installation Instructions
SMA Solar Technology AG Troubleshooting
Installation Guide SB11_12_17-IEN100132 37
The approximate position of the ground fault can be determined from the ratio of the measured
voltages between plus against ground potential and minus against ground potential.
Example:
The ground fault is between the second and third module in this case.
3. Repeat step 2 for each string.
The table illustrated below shows the various results and corresponding measures.
☑ The ground fault check is finished.
Result Action
☑You have found a ground fault. • The installer of the PV generator must
remedy the ground fault in the affected
string before you may reconnect the string
to the Sunny Boy.
•Do not reconnect the faulty string.
• Close and commission the Sunny Boy as
described in section 7.2 "Closing the
Sunny Boy" (page33).
☑You have found no ground fault. It is likely that one of the thermally monitored
varistors is defective.
• Check the varistors as described in section
9.1.2 "Checking the Function of the
Varistors" (page38).