SMA SI 4548-US - Manual (Page 133)

SMA America, LLC 14 Connecting External Sources
Operating Manual SI4548-6048-US-BE-en-20 133
Silent Mode
In order to save energy, the silent mode can be activated using the parameter "224.01 SilentEna" 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 13.5.5 "Silent
Mode", page 113).
The silent mode is quit 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 parameter
"232.08 GdMod".
The wire size 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).
The following illustration shows the direction of energy flow for the "Net Metering" and the energy
consumption from the utility grid.
Grid feed-in from the DC side into the utility grid
In order to allow electricity to be fed from the DC side into the utility grid, the battery voltage in
a charged battery (on the utility grid) must be increased by external DC chargers or the
Sunny Island Charger above the nominal charging voltage.