SMA SI 4548-US - Manual (Page 149)

SMA America, LLC 17 PV Inverters
Operating Manual SI4548-6048-US-BE-en-20 149
17 PV Inverters
The following section provides information on the connection and configuration of the Sunny Boy in
stand-alone grid systems.
The Sunny Island together with the Sunny Boy are optimized for battery-backup operation (grid-tied)
and for "Off-Grid" use.
This section describes the parameter setting of the Sunny Boy for both kinds of application. In
battery-backup operation, the parameter must be set to "Default" in accordance with UL 1741. In
parallel grid operation, the Sunny Island automatically detects a power outage and automatically
switches the Sunny Boy inverter to "Off-Grid" mode. To set up this arrangement, the Sunny Island and
the Sunny Boy must be connected with a data cable and the parameter of the Sunny Boy inverters
must be set according to this document. If the utility grid is activated, the Sunny Island switches back
to grid-tie operation in accordance with "UL 1741".
17.1 Connection to the Stand-Alone Grid (Protected Load Switch)
• Connect the Sunny Boy to the stand-alone grid in accordance with the Sunny Boy installation
manual.
• Connect the AC sub-distribution to the AC1 terminals of the Sunny Island. This AC
sub-distribution is where the PV inverter will be connected as well.
• You must set the corresponding parameters in the Sunny Boy to suit a stand-alone grid so that
it works properly together with the Sunny Island. The required values for these settings are
described in the next section.
PV inverters compatible with the Sunny Island
You will find the list with compatible PV inverters in the download are at
www.SMA-America.com in the Technical Information "PV Inverters: Use of PV Inverters in
Off-Grid Systems and Battery-Backup Systems North America and South America".
Interface for external communication in Sunny Island systems with the utility grid
If the utility grid is connected to the Sunny Island system as an external source, the RS485
communication between the Sunny Island and the PV inverters is necessary. For this, the
following devices each need one RS485 interface:
• the Sunny Island (if there are several Sunny Island inverters, the Sunny Island master)
• each PV inverter
Danger to life due to high voltages in the Sunny Island system. Death or serious injury
possible due to electric shock
• Ensure that the entire connection area of the Sunny Island 4548-US / 6048-US is voltage-free
before installing the Sunny Boy inverter.
• Observe the safety information (see Section 3 "Safety", page 26).