Communication For Multi-Device Connection - SMA SUNNY ISLAND 4548-US Operating Manual

6 Electrical Connection
Installation notice
The battery current sensor must be looped around the negative terminal of the battery. The
terminal of the battery current sensor which is connected to the Sunny Island (1), must be
connected to the terminal "BatCur+" (see example).
• Positive battery current means that the battery is being discharged (current from the
battery).
• Negative battery current means that the battery is being charged (current into the battery).
1. Pierce a hole at a suitable location in the cable support sleeve using a sharp object.
2. Starting from the outside, lead the insulated conductors with bootlace ferrules through the hole
in the Sunny Island.
3. Connect the insulated conductors correspondingly to the "BatVtgOut" terminal of the 4-pole
terminal included in the delivery.
4. Tighten the terminals (torque: 5 in-lb to 7 in-lb (0.56 Nm to 0.79 Nm)).
5. Insert the 4-pole terminal into the "BatTmp" pin connector on the Sunny Island.
☑ The battery current sensor is installed.
Commissioning the battery current sensor
When connecting a battery current sensor to the Sunny Island, you must set the device-internal
offset during the initial start-up of the off-grid system on the Sunny Island as described(see
Section 8.3 "Commissioning the battery current sensor", page 73).

6.4.5 Communication for Multi-Device Connection

The Sunny Island can be connected in parallel, as a split-phase system or in a three-phase system with
other Sunny Island inverters in order to increase the overall power. The Sunny Island inverters
communicate with each other via an RJ45 data cable. A black RJ45 cable is provided with each
Sunny Island. You need it in order to establish an (internal) communication between several
Sunny Island inverters. The maximum overall length of the communication bus of 98 ft (30 m) must
not be exceeded. If you operate only one Sunny Island in your system, the cable is not required.
Proceed as follows to implement the connection:
1. Remove one of the two plugs from the cable support sleeve.
2. Lead the RJ45 cable from the outside through the plugs inside the master.
3. Remove the terminator plugged into the "ComSyncOut" pin connector of the master and insert
it in "ComSyncIn" pin connector of the master.
4. Plug the RJ45 cable into the "ComSyncOut" pin connector.
5. Connect the master with slave:
56 SI4548-6048-US-BE-en-21
SMA Solar Technology America LLC
Operating Manual