4 product description, 1 sma pv offset box – SMA PVO-N-20 User Manual
Page 11

SMA Solar Technology AG
4 Product Description
Installation Manual
PVO-BOX-IA-en-10
11
4 Product Description
4.1 SMA PV Offset Box
The SMA PV Offset Box dissipates power-reducing charges in PV modules.
Figure 4: Parts of the SMA PV Offset Box
The SMA PV Offset Box is connected in parallel with the inverter and applies a voltage against earth
to PV modules. It can apply a set voltage or automatically regulate its output voltage.
Depending on its configuration, the SMA PV Offset Box performs various functions. Overnight, it can
dissipate PV modules charges which have accumulated during the day. In continuous operation, the
SMA PV Offset Box regenerates PV modules whose efficiency was previously reduced.
The SMA PV Offset Box continually monitors the connection of the functional earthing (FE) and the
insulation of the PV plant. Prior to starting operation, the SMA PV Offset Box checks whether the
PV strings are reverse poled or interrupted. Faults are displayed via LEDs.
Item
Description
Explanation
A
LEDs
LEDs for operation and fault display
B
Type label
‒
C
Connection area
Cable glands for the AC connection and DC connector