Check The Function Of The Varistors - SMA SUNNY MINI CENTRAL 6000TL Installation Manual

Troubleshooting
9.1.2 Check the function of the varistors.
Varistors are wearing parts. Their functioning diminishes with age or following repeated responses as
a result of overvoltages. It is therefore possible that one of the thermally monitored varistors has lost
its protective function.
You can check the varistors in the following way:
1. Open the Sunny Mini Central as described in section 7.1 „Opening the Sunny Mini Central"
(46).
2. Use a multimeter to check both varistors and see if there is a conducting connection between
connectors 2 and 3 (position see section 5.1.2 „View from Inside" (20)).
Event
There is a conducting connection:
There is no conducting connection:
3. Replace both varistors with new ones as shown in
this drawing. Varistor failure is generally due to
influences which affect all varistors similarly
(temperature, age, induced overvoltage).
If you do not receive a special tool for operating the
terminal clamps together with your replacement
varistors, please contact SMA. As an alternative,
the terminal contacts can be operated using a
3.5 mm wide screwdriver.
Ensure the varistors are installed the right way
round.
56 SMC6-8TL-IEN093231
Measure
There is probably another fault in the Sunny Mini Central.
• Close the Sunny Mini Central as described in
section 7.2 „Closing the Sunny Mini Central" (48).
• Discuss further steps with the SMA Technical
Serviceline.
The respective varistor is not working and must be
replaced.
The varistors are specially manufactured for use in the
Sunny Mini Central and are not commercially available.
They must be ordered directly from SMA Solar
Technology AG (SMA order code: "MSWR-TV7").
• To replace the part, proceed to step 3.
SMA Solar Technology AG
Insert the extractor tool
to open the terminal
clamp.
Remove
varistor.
The pole with the small loop (crimp)
must be fitted to terminal 1 when
replacing the varistor.
Installation Guide