SMA SB 2500 Installation - Manual (Page 56)

Troubleshooting SMA Solar Technology AG
56 SB25-30-IA-en-51 Installation Manual
9.3.1 Checking the PV Array for Earth Faults
1. Disconnect the inverter from both the DC and AC sides as described in Section 7.2 "Opening
the Inverter" (page 44).
2. Measure the voltages between the positive pole of
each string and the earth potential (PE).
3. Measure the voltages between the negative pole of
each string and the earth potential (PE).
4. Measure the voltages between the positive and
negative poles of each string.
☑ An earth fault exists if the measured voltages are stable and the sum of the voltages from the
positive pole to the earth potential and from the negative pole to the earth potential of a
string is approximately equal to the voltage between the positive and negative poles.
DANGER!
Risk of lethal electric shock
• Only touch the cables of the PV array on their insulation.
• Do not connect strings with earth faults to the inverter.
NOTICE!
Excessive voltages can destroy the measuring device.
• Only use measuring devices with a DC input voltage range up to at least 1 000 V.