3 the disconnect unit for sunny central, 1 operating principles, 2 identifying the disconnect unit – SMA SC 250U User Manual
Page 15: The disconnect unit for sunny central, Operating principles, Identifying the disconnect unit, Figure 2: type label disconnect unit

SMA America, LLC
3 The Disconnect Unit for Sunny Central
Installation Guide
DISU_SCUS-IA-IUS111711
15
3 The Disconnect Unit for Sunny Central
3.1 Operating principles
The PV modules convert a portion of sunlight into electrical energy (direct current). The inverter then
converts the direct current into alternating current and feeds it into the power distribution grid. This
current can be used directly, or it can be sold to your energy provider. The Disconnect Unit is for
disconnecting the inverter from the PV modules and from the power distribution grid for service and
maintenance issues and in case of emergency as demanded by National Electrical Code
®
2008.
3.2 Identifying the Disconnect Unit
You can identify the Disconnect Unit by its type label. The type label is located at the top right of the
rear wall.
Figure 2: Type label Disconnect Unit
www.SMA-America.com
DISCONNECT-UNIT
Engineered in Germany - Assembled in Denver/Colorado
Model:
Serial No.:
DC-SC-US
xxxxxxxxxx
Fabrication Version
xx/xxxx
Allowed Inverter Type xxxxxxx - xx/xx
DC Rating:
Maximum Array system voltage xxx Vdc
Maximum operating current xxxx Adc
AC Ratings:
Operating voltage range
(Vac 3-Phase)
Min. xxx
Nominal xxx
Max. xxx
Max. continous output current xxxx Aac
Operating frequency range
(Hz)
Min. xx.x
Nominal xxx
Max. xx.x
For more electrical ratings see in the
Inverter manual.
Other Ratings*
Operating temperature range
(-25 °F ... +50 °C)
Maximum Air ambient
without De-Ratings (°C)
50 °C
ENCLOSURE
Type 3R (IP54)
* For more details and tightening torqe, allowable wire size
and type see Disconnect unit Operators‘s manual.
Listet Accessory Photovoltaik / AC Grid Disconnect
US80
Date of manufacture
Max. continous output Power xxxx kWac