SMA SB 5000TL Multi-String Installation - Manual (Page 17)

SMA Technologie AG Requirements for the Installation
Installation Guide SB5000TL-12:SE2006 Page 17
The Sunny Boy 5000TL Multi-String does not generate any extraordinary capacitive
discharge currents in normal operation. In certain cases (e.g. the internal testing of
the safety components within the Sunny Boy 5000TL Multi-String) discharge currents
can occur that can trip a 30 mA GFCI.
The system impedance at the installation site of the Sunny Boy 5000TL Multi-String
must be less than 1 Ohms for the islanding detection and the fuses to work porperly.
Furthermore you should have a suitable cable cross-section in order to keep the loss-
es below 1 % at nominal power. The according losses with respect to cable length
and cross-section are illustrated below. It is based on a multi-conduit cable with all
conduits made of copper.
The maximum cable lengths for the different cable cross-sections are as follows:
Install a 100 mA GFCI in the AC distribution in case an additional GFCI is ab-
solutely necessary.
Conductor cross-section 4.0 mm² 6.0 mm² 8.0 mm² 10.0 mm²
Max. length 12 m 18 m 24 m 31 m
0.0%
0.2%
0.4%
0.6%
0.8%
1.0%
1.2%
1.4%
Length
5 m 10 m 20 m 30 m 40 m 50 m
Losses
0 m 15 m 25 m 35 m 45 m
4.0 mm²
6.0 mm² 8.0 mm²
10.0 mm²
Do not use cables where the losses will exceed 1.0 %