Maintenance and cleaning
SMA America, LLC
74
SB20_25_30HFUS-eng-IUS113711
Installation Guide
9.2 Checking the SMA DC Disconnect
When used appropriatly the SMA DC Disconnect does not need maintenance.
It is recommended, though not compulsory to:
• Check the SMA DC Disconnect regularly.
• Operate the SMA DC Disconnect once a year 10 times.
Operating the switch will clean the contacts of the SMA DC Disconnect.
9.3 Exchanging fuses
9.3.1 Exchanging SMA Plug-in Grounding fuse
SMA Plug-in Grounding enables for array grounding and contains a fuse for Ground Fault Indication
(GFDI). If a ground fault occurs, the fuse in the SMA Plug-in Grounding disconnects the fault current
generated. Once the ground fault is eliminated (see section 11.1 ”Checking the PV array for Ground
Fault” (page 88)), you must replace the fuse of the SMA Plug-in Grounding.
Dismantling and opening the SMA Plug-in Grounding
1. Disconnect the Sunny Boy from voltage sources (see section 8.1 ”Disconnect the Sunny Boy
from Voltage Sources” (page 65)).
2. Open the SMA DC Disconnect (see section 8.2 ”Open SMA DC Disconnect” (page 66)).
3. Remove the SMA Plug-in Grounding. Turn it in
counterclockwise direction and then pull it down.
☑ The SMA Plug-in Grounding is loosened from its
bracket.
4. Hold the connection part of the SMA Plug-in
Grounding tightly, loosen and remove the cap of
the SMA Plug-in Grounding.
