SMA SC 250U - Manual (Page 12)

2 Safety SMA America, LLC
12 DISU_SCUS-IA-IUS111711 Installation Guide
2 Safety
This section describes general safety regulations which must be observed throughout the entire
installation process. Pay attention to this section to avoid personal injury and material damages.
2.1 Appropriate usage
The Disconnect Unit for Sunny Central inverter is a AC/DC disconnect that extends the range of
functions of the inverter. You can use the Disconnect Unit to disconnect the inverter from PV modules
and from the power distribution grid as requested by the National Electrical Code
®
ANSI/NFPA 70.
Principle of a PV plant with a inverter with Disconnect UnitPrinciple of a PV plant with a inverter with Disconnect Unit
Figure 1: Principle of a PV plant with a inverter with Disconnect Unit
Any other application of the inverter, of the Disconnect Unit or installation of components and
modifications which are not allowed explicitly endanger the safety and void the warranty as well as
the operation permit.
• It is prohibited to use the inverter and the Disconnect Unit for purposes other than those
described here.
• It is prohibited to modify the inverter or the Disconnect Unit or to install components that are not
explicitly recommended or sold by SMA.
Position Description
A PV modules
B DC distribution with DC fuses (e.g., Sunny Central String-Monitor)
C Sunny Central
D Disconnect Unit
E Transformer
F Power distribution grid