SMA Solar Technology AG
50
SB50US-80US-IUS094030
Installation Guide
5.5.3 AC Wiring With SMA DC-Disconnect
Use the following procedure to connect the AC wires to the Sunny Boy with the SMA DC-Disconnect:
1. Turn OFF the main breaker in the main utility breaker box.
2. Remove interior breaker panel cover.
3. If you are replacing an existing inverter, disconnect the wires for the AC line you are working
with in the breaker box.
4. Install a 3/4-inch conduit fitting in the SMA DC-Disconnect AC wiring knockout (the knockout
on the right side of the SMA DC-Disconnect). Fasten the conduit fitting on the inside of the SMA
DC-Disconnect with the appropriate locknut.
5. Install 3/4-inch conduit between the main breaker box and the SMA DC-Disconnect’s AC
wiring knockout.
6. Pull the AC wires through the conduit from the interior of the breaker box to the interior of the
SMA DC-Disconnect.
WARNING!
You must connect the wires that carry the AC voltage from the Sunny Boy to the utility grid
in the order described in this procedure. Deviating from this procedure could expose you
to lethal voltages that can cause serious injury and/or death.
CAUTION!
Avoid using wire nuts to join any wires together or to make any connections anywhere in
the PV system. Wire nuts are a frequent cause of unreliable, resistive connections, and
ground faults.
The terminal must be opened completely before you insert the cable.
7. Connect the AC equipment-ground wire to the PE
terminal labeled
in the SMA DC-Disconnect.
