SMA Sunny Island 4548-US, Technical Description

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SMA America, LLC 14 Connecting External Sources
Technical description SI4548_6048-US-TB_en-13 133
Silent Mode
In order to save energy, the silent mode can be activated using the "224.01 SilentEna" parameter set
to "enable" (default disable). In this case, the Sunny Island is set to standby mode if the charge has
been completed and the battery has been in float charge for some time (see Section 13.4.5 "Silent
Mode", page 113).
The silent mode is exited regularly to recharge the battery.
In a single-phase parallel Sunny Island system, only the master detects a grid failure in silent mode.
The slaves do not detect a grid failure in silent mode.
Feed-In Operation
Whether energy is fed from the stand-alone grid into the utility grid is controlled using the
"232.08 GdMod" parameter.
The cross-section of the lines to the utility grid must be appropriate for the maximum current. This
ensures that the Sunny Island can feed into the utility grid with a full battery and at full solar irradiation.
In all cases, make sure to consult your grid operator if grid feed-in is possible.
If GdCharge is set, no energy is fed into the grid. If GridFeed (Default) is set, energy is fed into the
grid.
AC feed-in generators on the stand-alone grid side (Sunny Boy) can feed their energy into the utility
grid through the internal transfer relay of the Sunny Island; limitations (see Section 14.1.6 "Limits and
Power Control", page 125).
Feeding into the grid on the DC side
In order to allow electricity to be fed from the DC side into the grid, the battery voltage in a
charged battery (on the grid) must be increased by external DC chargers or the Sunny Island
Charger above the nominal charging voltage.