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SMA STP 8000TL-10 User Manual

Page 86

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12  Troubleshooting

SMA Solar Technology AG

86

STP8-17TL-IA-en-31

Installation Manual

☑ 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 location of the earth fault can be calculated from the ratio of the voltages
measured between plus and earth potential and minus and 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 (see Section 7

"Commissioning", page 58).

☑ You have not detected any earth fault. It is likely that one of the thermally monitored

varistors is defective.

• Check varistors (see Section 12.3

"Checking the Function of the Varistors",
page 87).