Wiring the Sunny Boy
SMA America, LLC
44
SB20_25_30HFUS-eng-IUS113711
Installation Guide
Check both the polarity and the open-circuit voltage from the PV strings!
6.3.1 Installing cable conduits and leading cable into the Sunny
Boy
CAUTION
Verify the polarity and the open-circuit voltage from the PV strings before you connect the
DC wires to the Sunny Boy. Applying an open-circuit DC-input voltage that exceeds the
maximum DC-input-voltage range will cause irreversible damage to the Sunny Boy and
void the warranty! Always configure the DC-input-voltage range correctly before
connecting the DC-input wires from the PV array to the Sunny Boy. Use Sunny Design at
www.SMA‑America.com to determine the correct string configuration.
Series fusing may be required depending on the type of PV module and the number of
strings used in the system. See
National Electrical Code
®
690.9.
CAUTION
Ground faults, unreliable and resistive connections due to faulty wire nuts.
• Avoid using wire nuts to join any wires together or to make any connections
anywhere in the PV system.
NOTICE
Ingress of water when mounting and installing the Sunny Boy.
Damage to the Sunny Boy will result.
• Do not enlarge openings for the cable conduits. The openings are intended for the
installation of inflexible cable conduits of a size of up to
3
⁄
4
in. (19 mm).
• For conduit hubs, use only UL Listed raintight, or wet location hubs of type 3R for entry
into the enclosure.
