SMA SUNNY ISLAND 6.0H - Emergency Disconnection; Time-Controlled Operation

3 Functions and Design
SMA Solar Technology AG
System Description 19SI44M-80H-13-MC-IA-en-10
The SunnyIsland inverter offers the following functions for multicluster systems with stand-alone grid via two
multifunction relays (see installation manual of the SunnyIsland inverter):
Function Description
Controlling PV arrays A multifunction relay activates if a PV array request is received from the SunnyIs-
land inverter's generator management system. With the multifunction relay, you
can control PV arrays with an electrical remote-start function or connect a signal
generator for PV arrays with no autostart function.
Controlling load-shedding con-
tactors
A multifunction relay is activated depending on the state of charge of the battery.
Depending on the configuration, you can install a one-level load shedding with
one multifunction relay or a two-level load shedding with two multifunction relays.
You can also adjust the thresholds for the state of charge of the battery depend-
ing on the time of day.
Time control for external pro-
cesses
External processes can be time-controlled with a multifunction relay.
Display of operating states and
warning messages
You can connect message devices to the multifunction relays to allow operating
states and warning messages from the SunnyIsland inverter to be output. One of
the following operating states and warning messages can be displayed for each
multifunction relay:
• The PV array is running and is connected.
• A SunnyIsland displays an error message of level 2 or higher. Only the
error messages within a cluster are evaluated here.
• A SunnyIsland displays a warning. Only the warnings within a cluster are
evaluated here.
Control of a battery-room fan The multifunction relay is activated when the charging current causes the battery
to emit gasses. A connected battery room fan is switched on for at least one
hour.
Control of an electrolyte pump Depending on the nominal energy throughput, the multifunction relay is activated
at least once a day.
Use of excess energy During the constant voltage phase, a multifunction relay is activated and thus
controls additional loads that can put any excess energy of AC sources in the
stand-alone grid (e.g., of a PV system) to good use.
3.4 Multicluster System with Increased Self-Consumption and Battery-
Backup Function
3.4.1 Principle of a System with Increased Self-Consumption and Battery-Backup
Function
Multicluster systems with increased self-consumption and battery-backup function (battery-backup systems) are
connected to the utility grid via a Grid-Connect-Box.
When the system with increased self-consumption and battery-backup function is connected to the utility grid,
SunnyIsland inverters can use the batteries for intermediate storage of PV energy. The stored PV energy can then be
used by your appliances during the evening and nighttime hours. With this, electricity purchased from the grid can be
reduced and self-consumption or internal power supply optimized.