SMA WB 5000A-11 Installation - Manual (Page 72)

Troubleshooting SMA Solar Technology AG
72 WB5A_6A-IA-IEN114540 Installation Manual
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.
You can check the function of the varistors as follows:
1. Open the inverter as described in Section 7.2 "Opening the Inverter" (page 57).
2. Use a multimeter to check that all the installed
varistors have a conductive connection between
connectors B and C.
Position of varistors
The position of the varistors can be determined with the help of the diagram below.
Observe the following assignment of the terminals:
• Terminal A: outer terminal with loop
(varistor connection with crimp)
• Terminal B: middle terminal
• Terminal C: outer terminal with loop
(varistor connection without crimp)
Result Measure
There is a conductive connection. There must be a different error in the inverter.
• Close the inverter as described in
Section 7.3 "Closing the Inverter" (page 59).
• Contact the SMA Service Line.