SMA SUNNY BOY 3600TL - Page 85

SMA Solar Technology AG 12 Troubleshooting
Installation Manual SB30-50TL-21-IA-en-21 85
☑ An earth fault is present if the measured voltages are stable and the sum of the voltages of
the positive pole against earth potential and the negative pole against earth potential of a
string is approximately equal to the voltage between the positive and negative poles.
Location of the earth fault
The approximate position of the earth fault can be determined from the ratio of the measured
voltages between the positive pole against earth potential (PE) and the negative pole against
earth potential (PE).
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 (electrically skilled person) of the
PV array must remedy the earth fault in the
affected string before you reconnect the
string to the inverter. You can determine the
location of the earth fault using the illustration
below.
• Do not reconnect the faulty string.
• Restart the inverter (see Section7.1
"Commissioning the Inverter", page57).
☑You have not detected an earth
fault.
One of the thermally monitored varistors is
probably defective.
• Check the function of the varistors
(see Section12.6 "Checking the Function of
the Varistors", page86).