SMA SUNNY ISLAND 4.4M Operating Manual page 53

SMA Solar Technology AG
Load-shedding contactors in a cluster
If you connect load-shedding contactors to the master, limited operation is possible in the event of a disturbance.
Slaves can control the load-shedding contactors less reliably in the event of a fault. In the event of a disturbance,
the slave may wait for confirmation from the master.
Figure 13: Connection of control cable for one-level load shedding (example)
Requirements:
☐ The technical requirements of the multifunction relay must be met (see Section 17 "Technical Data", page 180).
Cable requirements:
☐ Copper wire
☐ Conductor cross-section: 0.2 mm² to 2.5 mm²
Procedure:
1. Ensure that the load-shedding contactor only disconnects loads from the system. This ensures that the battery can
be recharged from AC sources in the system.
2. When connecting the load shedding, preferably use the multifunction relay Relay2. Since the default setting of
Sunny Island uses the multifunction relay Relay2 for load shedding. Perform the following steps:
• Connect the insulated conductor for coil connection A1 of the load-shedding contactor on the Sunny Island
to terminal Relay2 NO (see Section 6.6.5 "Connecting Relay 1 and Relay 2", page 65).
• Connect the insulated conductor for coil connection A2 to terminal BatVtgOut− (see Section 6.6.6
"Connecting BatVtgOut, DigIn, BatTMP and BatCur", page 66).
• Connect terminal BatVtgOut + to terminal Relay2 C. Use the same conductor cross-section as that of the
cable for the load-shedding contactor.
3. If the multifunction relay Relay2 for load shedding is not available, use the multifunction relay Relay1 when
connecting the load shedding. Perform the following steps:
• Connect the insulated conductor for coil connection A1 of the load-shedding contactor on the Sunny Island
to terminal Relay1 NO (see Section 6.6.5 "Connecting Relay 1 and Relay 2", page 65).
• Connect the insulated conductor for coil connection A2 to terminal BatVtgOut− (see Section 6.6.6
"Connecting BatVtgOut, DigIn, BatTMP and BatCur", page 66).
• Connect terminal BatVtgOut + to terminal Relay1 C. Use the same conductor cross-section as that of the
cable for the load-shedding contactor.
4. Enter the selected configuration into the table of the settings (see Section 7.10.2 "Setting the Functions of the
Multifunction Relays", page 108):
Value
One-level load shedding
Operating Manual
Explanation
Setting for one-level load shedding. When the Sunny Island
switches to an external energy source, load shedding is stopped
and the loads are supplied by the external energy source. The bat-
tery is only charged with the excess energy.
6 Electrical Connection
SI44M-80H-12-BE-en-10 53