SMA SUNNY ISLAND 4.4M Operating Manual page 93

SMA Solar Technology AG
The time-dependent load shedding divides the day into two intervals (see Section 9.8.2 "Setting Time-Dependent
Functions", page 123). You set the SOC thresholds that apply for each interval. For example, you can set that no
loads are to be disconnected from the utility grid during the night where possible.
Significance of the SOC thresholds:
When the state of charge of the battery reaches the lower SOC threshold, the multifunction relay opens the connected
load-shedding contactor. The load-shedding contactor disconnects the loads from the utility grid. When the state of
charge of the battery reaches the upper SOC threshold during recharging, the multifunction relay closes the connected
load-shedding contactor. The load-shedding contactor connects the loads to the utility grid.
Example: from 10:00 p.m. to 6:00 a.m., the load-shedding contactor is not to disconnect the loads from
the utility grid where possible.
SOC
80 %
40 %
30 %
12 a.m.
Standard time period
Figure 21: Profile of the SOC thresholds for controlling the load-shedding contactor and the start times for the intervals
The start time for the first interval is set to 6:00 a.m. The lower SOC threshold is set to 40% and the upper SOC
threshold is set to 80% in this time interval.
The start time for the second interval is set to 10:00 p.m. The lower SOC threshold is set to 30% and the upper SOC
threshold is set to 40% in this time interval.
Procedure:
1. Select Device > Load shedding 1 > Additional time range.
2. Set the parameters for the standard time period:
• Set the parameter Time load shedding 1 to the start time for the standard time period.
• Set the parameter Lmt value battery state of charge for start load shedding 1 to the lower SOC
threshold for the standard time period.
• Set the parameter Lmt value battery state of charge for stop load shedding 1 to the upper SOC
threshold for the standard time period.
3. Set the parameters for the additional time period:
• Set the parameter Start time additional time range load shedding 1 to the start time for the additional
time period.
• Set the parameter Limit battery state of charge for start load shedding 1 in add time range to the
lower SOC threshold for the additional time period.
Operating Manual
6 a.m.
Additional time period
7 Commissioning
10 p.m.
SI44M-80H-12-BE-en-10
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