SMA SI 3.0-11 Installation - Manual (Page 31)

SMA Solar Technology AG 7 Electrical Connection
Installation Manual SI30M-44M-60H-80H-IA-en-30 31
7.4.4 Connecting the Stand-Alone Grid or Multicluster Box
In the off-grid system, connect the AC loads and the grid-parallel AC sources (e.g. PV inverters) to connection
AC1 on the Sunny Island inverter via an AC distribution board. In the case of a multicluster system, the
Multicluster Box is the AC distribution board that is connected to connection AC1.
Requirements for connecting Sunny Island inverters in single-phase parallel single-cluster systems:
Figure 9: Correct, symmetric connection and incorrect, asymmetric connection of the Sunny Island inverters
☐ For a single-phase parallel single-cluster system, the cable length and conductor cross-section from each
Sunny Island to the AC distribution board must be identical. This will allow for stable and symmetric operation.
Procedure:
1. On the Sunny Island, connect the cable to the AC1 Loads/
SunnyBoys terminal. Ensure that the cable is correctly connected
(see Section 7.5.2 "Connecting the AC Power Cable", page 52).
2. If the conductor cross-section of the grounding conductor is less than 10 mm², make sure that an additional
grounding conductor is connected to terminal AC2 Loads/SunnyBoys PE (see Section 7.5.3 "Connecting the
Grounding Conductor", page 53).
:$51,1*
Danger to life due to fire
In case of a short circuit, the short-circuit current driven by the generator flows over the unfused cable between the
Sunny Island and the AC distribution board. Short-circuit currents can cause fires.
• If the generator fuse is larger than the fuse on the AC distribution board, configure the cable for the generator fuse.