SMA SC 250U - Manual (Page 60)

6 Electrical connection SMA America, LLC
60 DISU_SCUS-IA-IUS111711 Installation Guide
6.7 Affixing information about grounded path
1. Determine if the PV plant is positive or negative grounded:
In a PV plant only the cables of the ungrounded path are disconnected by breakers, DC load
break switches and fuses.
To determine if the PV system is positively or negatively grounded, check the routing of the DC
cables for disconnectors and fuses. DC cables without any disconnection belong to the
grounded DC path.
If the DC cable without disconnectors is positive: the PV plant is positively grounded.
If the DC cable without disconnectors is negative: the PV plant is negatively grounded.
2. Affix the label that indicates the grounded path of
the DC system to the front plate of the Disconnect
Unit.
There are 2 labels included in the scope of delivery
for indicating the grounded path of the DC system.
Depending on which path of the DC system is
grounded affix label for positive or negative
grounding to the front plate of the Disconnect Unit.