SMA SB 700 User Manual
Page 17

SMA
Technologie AG
Installation requirements
Installation Guide
SB700-11:SA2006
Page 17
The system impedance at the installation site of the Sunny Boy 700 must be less than
1 Ohms for the islanding detection and the fuses to work porperly. In addition, we
recommend dimensioning the cable cross-section so that line losses do not exceed 1%
at the nominal power. Line losses depending on the cable length and cross-section
are shown in the graph below. It shows a multi-conduit cable with all conduits made
of copper.
The maximum cable lengths for the different cable cross-sections are as follows:
Cable cross-section
1.5 mm²
2.5 mm²
Max. length
33 m
55 m
0,0%
0,2%
0,4%
0,6%
0,8%
1,0%
1,2%
1,4%
Cable length
0 m
10 m
15 m
20 m
25 m
30 m
35 m
40 m
45 m
50 m
5 m
Loss
1,5 mm²
2,5 mm²
Do not use cables where the losses will exceed 1.0 %.