SMA America, LLC
Electrical Connection
Installation Guide
SB50US-80US-eng-IUS112633
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Fuses
The DC disconnect for the inverter must have a minimum rating of 600 V DC and 36 A continuous.
The SMA DC Disconnect is supplied with 4 fuses (one fuse per string) designed for 15 A and
600 V DC. The 4 fuses of the SMA DC Disconnect may be used for a maximum of 20 A and
600 V DC.
6.5.2 DC Input Grounding
The Sunny Boy configured ex works for plants with negative generator grounding. Certain types of
PV modules may make it necessary to ground the negative pole rather than the positive pole.
Position of the GFDI Fuse and the Jumper During Negative Grounding
1. Insert the fuse in position (1).
2. Insert the jumper in position (2).
Position of the GFDI Fuse and the Jumpers During Positive Grounding
1. Insert the fuse in position (1).
2. Insert the jumper in position (2).
Depending on the type of the PV module and its interconnection in the plant, fuses
connected in series may be required. When dimensioning the fuses, observe the
National Electrical Code
®
690.8 and 690.9.
