SMA Sunny Island 4548-US, Technical Description

Page: 139 / 240

SMA America, LLC 14 Connecting External Sources
Technical description SI4548_6048-US-TB_en-13 139
The signal circuit occupies two auxiliary contactors at the DigIn input:
1. Connect the negative pole of the DigIn connection on the Sunny Island to the negative pole of
the BatVtgOut connection, also located on the Sunny Island.
2. Connect the positive pole of the DigIn connection to a NO connection of an auxiliary contact
of the transfer switch.
3. Connect the positive pole of the BatVtgOut connection to the second contact of the same
auxiliary contact on the transfer switch.
An auxiliary contact is used because the Sunny Island must "know" whether it is connected to the utility
grid or whether it must manage a diesel generator.
To enable such an operation, you must set the "231.06 ExtSrc" parameter to "GenGrid" (see
Section 8.2 "Starting the Quick Configuration Guide (QCG)", page 67).
Settings performed on the generator and grid
All the settings made for the generator and grid in the submenus also apply to the "GenGrid”
selection.