SMA America, LLC
Electrical Connection
Technical Description
SI5048U-TUS121440
43
6.2 DC terminal
6.2.1 Safety Precautions/Conditions
Connect a suitable battery to the DC side (see section 22 ”Technical Data” (page 216)). The DC
connection must observe all applicable local ordinances and guidelines.
6.2.2 Cable Sizing
Example of Cable Sizing
With a 48 V battery voltage and an outgoing AC power of 5 000 W, a current of up to 140 A flows
through the SI 5048U battery cable.
NOTICE
Function impairments of devices on the DC busbar.
The Sunny Island is
not
suitable for use with DC supply grids. Function impairment can
occur on devices installed on the DC side of a Sunny Island with cables exceeding 98 ft.
(30 m) and with a flexible connection.
• Only use fixed installations.
• Do not use cables of lengths greater than 98 ft. (30 m) between the Sunny Island
and the battery and/or DC device.
WARNING
Danger to life through chemical burns in the event of leaking acid.
Acid can escape in the event of improper handling of the battery.
• Observe all safety indications and warnings provided by the battery manufacturer.
• Use special (insulated) tools to mount and install the battery.
• Provide sufficient ventilation in the room in which the batteries are. When gasses are
produced by the batteries, these cannot be allowed to collect.
Keep the Cables to the Battery as Short as Possible
The battery cables should be as short as possible. Long cables and insufficient cable
diameters reduce the system efficiency as well as the overload capabilities. Do not lay the
battery lead under plaster or in armored plastic pipes.
Choice of Cable Cross-sections
SMA recommends choosing cable cross-sections greater than those given by
NEC 250.122 in the case of cable lengths exceeding 32.8 ft (10 m).
