SMA SB 3300 Installation - Manual (Page 59)

SMA Solar Technology AG Troubleshooting
Installation Guide SB33_38-IEN111851 59
4. Measure the voltages between the plus pole and
the minus pole of each string.
☑ If the voltages measured are stable and the total of the voltages from the plus pole against
ground potential and the minus pole against ground potential of a string roughly
corresponds to the voltage between the plus pole and minus pole, then there is a ground
fault.
Result Measure
☑ You have found a ground fault. • The installer of the PV generator must
remedy the ground fault in the affected
string. You can determine the location of the
ground fault as described below.
• Do not reconnect the faulty string.
• Commission the inverter as described in
section 6.1 ”Commissioning the Inverter”
(page 37).
☑ 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
9.3.2 ”Checking the Function of the
Varistors” (page 60).