SMA SB 3300-11 Installation - Manual (Page 58)

Troubleshooting SMA Solar Technology AG
58 SB33-38-11-IA-en-62 Installation Manual
Location of the ground fault
The approximate position of the ground fault can be determined from the ratio of the measured
voltages between the positive pole against ground potential (PE) and the negative pole against
ground potential (PE).
Example:
In this case, the ground fault is between the second and third PV modules.
☑ The ground fault check is finished.
9.3.2 Checking the Function of the Varistors
Varistors are wear parts. Their functional efficiency diminishes with age or repeated strain as a result
of overvoltage. It is therefore possible that one of the thermally monitored varistors has lost its
protective function.
Position of varistors
You can determine the position of the varistors using the illustration below. Observe the
following assignment of the terminals:
• Terminal A: outer terminal
(varistor connection with loop [crimp])
• Terminal B: middle terminal
• Terminal C: outer terminal (varistor
connection without loop [crimp])