Setting Two-Level Load Shedding
The basic procedure for changing operating parameters is explained in another section ( > Changing Operating Parameters).
Two multifunction relays control two load-shedding contactors depending on the state of charge of the battery.
Significance of the SOC thresholds:
Two lower and two upper SOC thresholds are available for each interval for controlling the load-shedding contactors. The load-shedding contactors disconnect the loads from the utility grid if the states of charge are as follows:
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When the state of charge of the battery reaches the first lower SOC threshold, the multifunction relay opens the connected load-shedding contactor for the first level of load shedding. The load-shedding contactor disconnects those loads from the utility grid that are to be disconnected for the first level.
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When the state of charge of the battery reaches the second lower SOC threshold, the multifunction relay opens the connected load-shedding contactor for the second level of load shedding. The load-shedding contactor disconnects the remaining loads from the utility grid.
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When the state of charge of the battery reaches the second upper SOC threshold during recharging, the multifunction relay closes the connected load-shedding contactor for the second level of load shedding. The load-shedding contactor connects those loads to the utility grid that were disconnected for the second level.
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When the state of charge of the battery reaches the first upper SOC threshold during recharging, the multifunction relay closes the connected load-shedding contactor for the first level of load shedding. The load-shedding contactor connects those loads, which were disconnected for the first level, to the utility grid. All loads are connected to the utility grid.
Procedure:
- Setting the First Level of Load Shedding:
Select Device > Load shedding 1 > Additional time range.
Set the parameter Lmt value battery state of charge for start load shedding 1 to the lower SOC threshold.
Set the parameter Lmt value battery state of charge for stop load shedding 1 to the upper SOC threshold.
Set the parameter Time load shedding 1 and the parameter Start time additional time range load shedding 1 each to the same value, e.g. to 00:00:00. This will switch the time-dependent load shedding off.
Ensure that the parameter of the multifunction relay has been set to 1-stage load shedding or 1st stage with 2-stage load shedding ( > Setting the Functions of the Multifunction Relays).
- Setting the second level of load shedding:
Select Device > Load shedding 2.
Set the parameter Lmt value battery state of charge for start load shedding 2 to the lower SOC threshold.
Set the parameter Limit battery state of charge for stop load shedding 2 in add time range to the upper SOC threshold.
Select Device > Load shedding 2 > Additional time range.
Set the parameter Time load shedding 2 and the parameter Start time additional time range load shedding 2 each to the same value, e.g. to 00:00:00. This will switch the time-dependent load shedding off.
Ensure that the parameter of the multifunction relay has been set to 1st stage with 2-stage load shedding ( > Setting the Functions of the Multifunction Relays).