SMA Solar Technology AG
Grid
Technical Description
SBU2200-TEN083320
121
15.2 Operating on the Public Grid
In grid operation, the loads and the Sunny Backup 2200 are connected to the public grid. In this case,
the voltage and frequency in both grids are identical. In grid operation, grid monitoring checks for
breaches of the permissible limits for voltage and frequency (see Grid Reconnection), and for grid
failure. If the thresholds are breached, or in the event of a complete grid failure, the public grid is
disconnected, and operation continues almost uninterruptedly as a stand-alone grid. In grid operation
the battery is normally charged or kept fully charged.
15.3 Grid Failure
A grid fault is characterized by the voltage or frequency being outside of the permissible limits (see
section 15.5 „Grid Reconnection“ (122)) or the main power grid being disconnected. In this case,
the time limits are relevant: Smaller deviations are permitted for longer than large deviations. In the
event of a grid fault/
failure, the public grid is disconnected and the Sunny Backup 2200 starts up if it is not already running
(silent mode).
15.4 Stand-Alone Grid Operation
The public grid is down and the loads are powered by the Sunny Backup 2200 in stand-alone grid
operation. The system waiting for the grid to reconnect is an indication of this state. As long as the
battery has a sufficient charge level, the loads are powered. In stand-alone operation, the battery is
charged by the PV system if applicable.
Extended switching times during grid failure
If the Sunny Backup 2200 is in silent mode when a grid failure occurs, a long interruption
time may result. Other operating conditions are described in section 15.1 „Conditions“
(120).
