SMC Networks Sunny Mini Central SMC 5000A - Manual (Page 66)

Troubleshooting / Problem Solving SMA Technologie AG
Page 66 SMC50A_60A-IEN073320 Installation Guide
3 Replace the varistor concerned with a new
one as shown in the illustration to the right.
Ensure the varistor is installed the right way
round! 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 suitable
screwdriver. Since the failure of one varistor
is generally due to factors that affect all
varistors in a similar way (temperature, age,
inductive overvoltages), you should replace
both varistors, not just the one that is
obviously defective.
If no replacement varistors are locally
available, the Sunny Mini Central can
temporarily run without them. To do this,
remove the varistors you identified as
being faulty as described above and in
their place, bridge the terminals 2 and 3
with a length of wire.
An input modified in this way is no longer protected
against overvoltages! Replacement varistors should be
obtained as soon as possible. In systems with a high risk
of overvoltages, the Sunny Mini Central must not be
operated without varistors.
4 Close the Sunny Mini Central as described in section 10.3 "Closing of the
Sunny Mini Central" (Page 60).
Step Instruction
Insert the
special tool to
open the
terminal clamp
Remove the
varistor
The pole with the small
loop (crimp) must be fitted
to terminal 1 when
replacing the varistor