SMA SI-TB-BOX-10 - Manual (Page 18)

4 Product Description SMA America, LLC
18 SI_TDBOX-IA-eng-IUS122211 Installation Manual
4.3 Bypass Switch
The bypass switch is a manual automatic transfer switch that makes it possible to directly supply the
loads through the generator or power distribution grid. By directly supplying the loads through the
generator or power distribution grid, the Smartformer bypasses the terminals of the PV plant and
Sunny Island. In this way, the Smartformer simplifies maintenance work and repairs.
Figure 4: Overview of the bypass switch
4.4 Load-Shedding Contactor
The load-shedding contactor is an automatic switch-off device used to protect the battery from deep
discharge.
When a predefined charge status limit of the battery is reached, the Sunny Island triggers the load-
shedding contactor. The load-shedding contactor disconnects the loads from the Sunny Island system.
By doing so, the Sunny Island prevents deep battery discharge.
Position Description Explanation
A Switch position "I ON" The Sunny Island supplies the loads and, in
doing so, integrates the generator or power
distribution grid, along with the PV plant.
B Switch position "O OFF" The loads are not supplied with voltage.
C Switch position "II ON" Generators or power distribution grids supply
the loads directly.