SMA STP 15000TL Installation - Manual (Page 76)

Troubleshooting SMA Solar Technology AG
76 STP20TLHE-IA-IEN122222 Installation Manual
☑ An earth fault is present if the measured voltages are stable and the sum of the voltages of
the plus pole against earth potential and the minus pole against earth potential of a string is
approximately equal to the voltage between the plus and minus poles.
Location of the earth fault
The approximate position of the earth fault can be determined from the ratio of the measured
voltages between plus against earth potential and minus against earth potential.
Example:
In this case, the earth fault is between the 2nd and 3rd PV modules.
☑ The earth fault check is now complete.
Result Measure
☑ You have detected an earth fault. • The installer of the PV array must remedy
the earth fault in the affected string. You can
determine the location of the earth fault as
described below.
• Do not reconnect the faulty string.
• Restart the inverter as described in Section
7 "Commissioning" (page 55).
☑ You have not detected any earth fault. It is likely that one of the thermally monitored
varistors is defective.
• Check the varistors as described in Section
11.2 "Checking the Function of the
Varistors" (page 77).