SMA Solar Technology AG
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SB50US-80US-IUS094030
Installation Guide
5.5 Wiring the AC Output
This subsection provides complete, step-by-step procedures for wiring the AC output from the Sunny
Boy to the utility grid.
5.5.1 AC Connection Requirements
The following diagrams show the potential losses in AC wires with respect to the cross-sectional area
of the cable and the length of the cable. Use the following diagrams to determine the best wire size
to use for your particular installation.
WARNING!
All electrical installations must be done in accordance with all local electrical codes and
with the National Electrical Code (NEC), ANSI/NFPA 70. Use #6 AWG (maximum), 90
°C (194 °F), copper wire for all AC wiring connections to the Sunny Boy. Voltage drop
and other considerations may dictate that larger size wires be used. Use only solid or
stranded wire but not fine stranded wire.
WARNING!
The National Electrical Code (NEC) states that the inverter must be connected to a
dedicated circuit, and that no other outlets or devices can be connected to the same circuit.
See NEC Section 690-64(b)(1). The NEC also imposes limitations on the size of the
inverter and the manner in which it is connected to the utility grid. See NEC Section 690-
64(b)(2).
WARNING!
To reduce the risk of fire, connect only to a circuit provided with the required branch circuit
overcurrent device sized in accordance with the National Electric Code, ANSI/NFPA 70.
The maximum size overcurrent device shall not be more than 50 amperes.