SMA SI 4548-US - Manual (Page 51)

SMA America, LLC 6 Electrical Connection
Operating Manual SI4548-6048-US-BE-en-20 51
Connecting the AC2 Cable (Generator/Grid):
1. Install a conduit with a diameter of
3
/
4
in. (19 mm) at the right opening on the left side of the
Sunny Island enclosure. Attach the conduit on the inside of the Sunny Island with a counter nut.
2. Install the conduit on the distribution board.
3. Pull the cable from the distribution board through the conduit into the Sunny Island.
4. Remove the protective insulation of the three cables (insulation stripping length: 0.75 in
(18 mm)).
5. Insert the grounding conductor into the terminal labeled "AC2 Gen/Grid" and tighten the
fastening screw with a torque of 22 in-lb (2.5 Nm). Use a torque wrench with flat-blade
screwdriver bit SZS 1.0 x 6.5.
6. Insert N and L into the terminals labeled "AC2 Gen/Grid" and tighten the fastening screws with
a torque of 22 in-lb (2.5 Nm). Use a torque wrench with flat-blade screwdriver bit SZS
1.0 x 6.5.
Additional fuses in the system
If there are no additional fuses installed between the generator or utility grid and the
Sunny Island, the Sunny Island knows whether it has a connection to the utility grid/to the
generator. The Sunny Island can then draw current from the utility grid/from the generator.
If there are additional fuses or switches installed between the Sunny Island and the utility grid/
the generator, the Sunny Island cannot determine whether fuses or switches are disconnected
or whether there is no voltage available from the utility grid/the generator. In either case the
Sunny Island cannot charge its battery and the loads that are in operation will discharge the
Sunny Island battery.
Check the additional fuses and switches regularly in order that the Sunny Island battery only
discharges when there is no voltage available from the utility grid/the generator.
Wire size
The maximum wire size for connecting the generator is 4 AWG (25 mm²).