SMA SB 4200TL Multi-String Installation - Manual (Page 17)

SMA Technologie AG Requirements for the Installation
Installation Guide SB4200TL-13:SE2006 Page 17
The Sunny Boy 4200TL 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 4200TL Multi-String) discharge currents
can occur that can trip a 30 mA GFCI.
The system impedance at the installation site of the Sunny Boy 4200TL Multi-String
must be less than 1 Ohms for the islanding detection and the fuses to work properly.
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 shows 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 14,5 m 22 m 29 m 37 m