Checking The Varistors - SMA SMC 5000A Installation Manual

Troubleshooting / Problem solving

10.2.2 :Checking 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 now check these varistors in
the following way, paying attention to the safety instructions in chapter 9.1 „Safety in-
structions" (Page 63):
Step Instructions
1 Open the Sunny Mini Central as described in section 9.2 „Opening of the
Sunny Mini Central" (Page 64).
2
Use a continuity tester to check all the varistors and see if there is a conduc-
ting connection between connectors 2 and 3. The positions of the varistors in
the Sunny Mini Central can be seen in the diagram in section 2.2 „Overview
of the device" (Page 10).
Event
There is a conducting
connection.
There is no conducting
connection.
Page 70 SMC50A_60A-11:SE3706
Measure
It is likely that there is a different fault in the
Sunny Mini Central which has activated the
blink code.
Close the Sunny Mini Central again as descri-
bed in chapter 9.3 „Closing of the Sunny
Mini Central" (Page 65) and contact the
SMA hotline to discuss further steps.
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.
ordered directly from SMA Technologie AG
(SMA order code: MSWR-TV6).
To replace the part, proceed to step 4.
SMA
Technologie AG
They must be
Installation Guide