SMA SB 1200 Installation - Manual (Page 57)

SMA Solar Technology AG Failure Search
Installation Guide SB12-17-IA-en-52 57
9.3.1 Checking the PV Generator for a Ground Fault
1. Disconnect the inverter from both the DC and AC connections as described in section
7.2 ”Opening the Inverter” (page 45).
2. Measure the voltages between the positive pole of
the strings and the ground potential (PE).
3. Measure the voltages between the minus pole of
the strings and the ground potential (PE).
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.
DANGER!
Risk of lethal electric shock.
• Only touch the cables of the PV generator on their insulation.
• Do not connect strings with ground 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.