SMA Sunny Boy SB 2500, Installation Manual

Page: 53 / 66

SMA Technologie AG Replacing the Varistors
Installation Guide SB25_30-11:SE0307 Page 53
9. Replace the varistor in question with a new
one as shown in the illustration to the right.
Ensure the varistor is installed the right way
around! If you do not receive a special tool
for operating the terminal clamps together
with your replacement varistors, 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), it is highly
recommended that you replace both
varistors, not just the one that is obviously
defective. The varistors are specially
manufactured for use in the Sunny Boy and
are not commercially available. They must
be ordered directly from
SMA Technologie
AG (SMA order code: SB-TV4).
Warning!
If no spare varistors are available on site, the Sunny Boy can once again
feed into the grid. The input 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 Boy should not be operated
with defective varistors!
10. Reconnect the PE connection on the cover and close the Sunny Boy.
11. Connect up the faultless PV generator strings
to the inverter.
12. Close the unused DC input sockets with the
caps included in the delivery.
13. Switch the line circuit breaker to the "on"
position.
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.
On