14 Connecting External Sources
SMA America, LLC
116
SI4548_6048-US-TB_en-13
Technical description
14 Connecting External Sources
The Sunny Island supports the integration of external energy sources. Here, a distinction is made
between the integration of a generator and the integration of the utility grid.
Both the generator as well as the utility grid are integrated through the AC2 connection of the
Sunny Island. A single-phase, a split-phase and a three-phase connection can be established. In the
case of single-phase parallel operation, the transfer relays are operated in parallel, making it possible
to use a correspondingly larger current, which in turn allows for a generator or grid connections with
a higher capacity
The Sunny Island has separate parameters for the grid and generator. This generally allows both
operating modes to be used without making additional adjustments. The parameter settings and
display values distinguish between settings or values which are generator-specific or grid-specific and
settings or values (EXT) common to both grid and generator.
14.1 Generator
The Sunny Island can start or stop a generator depending on load power or battery state of charge.
In this case, diverse limits and times are taken into consideration (see Section 14.1.5 "Automatic
Generator Operation", page 122).
Extended Generator Management
If necessary, the Sunny Island and generator supply loads together. The total of the (nominal) power
of both energy sources is available in the stand-alone grid.
14.1.1 Parallel Connection
In the case of Sunny Islands connected in parallel which operate on the same line conductor and in
the same cluster, the internal transfer relay is activated simultaneously. It is thus possible to multiply
the generator current and therefore to connect a larger generator or a higher grid current.
The maximum current in the system is limited to 150 A:
Connecting in a single-phase parallel system:
When installing parallel single-phase systems, the connection cables for AC1 and AC2 of all
Sunny Islands must have the same cable cross-sections and cable lengths.
Maximum number of Sunny Island
Maximum current
1 Sunny Island
56 A
2 Sunny Island
112 A
3 Sunny Island
150 A
Summary of Contents for Sunny Island 4548-US
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