SUNNY ISLAND 5048 - Technical Description - Wind & Sun Ltd.

Connecting External Sources SMA Solar Technology AG
14.3 Generator and Grid
In addition to the power distribution grid, a generator can also be integrated into a stand-alone grid
system as a secondary protective measure. This is particularly useful in case of long-term grid failures,
even if the battery size is no longer sufficient to bridge the failure after a period of time.
The common solution in such cases is using a transfer switch, which can be purchased as a manual
or automatic switch. By using such a switch, a diesel generator is connected to the AC2 connection,
to which the power distribution grid is normally connected, as displayed in the figure below:
To use such a switch, carry out the installation as follows.
NOTICE!
Destruction of the Sunny Island due to abrupt switch from power distribution grid
to generator and vice versa.
• If an automatic switch is installed, make sure that it completely disconnects the
Sunny Island from the grid and from the generator for at least 5 seconds.
• If a manual switch is installed, leave the switch in OFF-position for at least 5 seconds
before switching to the new position.
• Upon request to the SMA Serviceline, you can obtain the manual on how to install a
switch for connecting the Sunny Island to the power distribution grid and to a
generator.
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.
128 SI5048-TB-TEN110340 Technical Description