This special local control mode switches one or more relays on when the total state of charge of all the batteries on the site drops below a configurable value, and off again when it rises above another value. It is the general-purpose version of Switching on a generator at low battery state of charge: use it for any load or signal that must follow the state of charge of the batteries, for example a warning lamp, a load that may only run while there is enough energy in the batteries, or a contact towards a building management system.
Below the lower threshold, the selected relays are switched on.
Above the upper threshold, the selected relays are switched off.
Between the two thresholds, the relays keep their position (hysteresis), and a relay stays at least the configured minimum time in the same position.
Note
Note
The total state of charge is the capacity-weighted average of the state of charge of all the batteries of the site.
Note
Note
The timing settings of the relays (minimum and maximum switch on and off times) are ignored in this mode. Only the minimum hold time configured in the mode itself applies.
Warning
Warning
If the total battery capacity is zero (no batteries, or batteries without a configured capacity), the mode cannot decide and puts the relays in their default device state. The mode reports this as an error on the external signals page.
Add the relay through the device wizard, see Adding a device: choose 'On/off load', 'Generic', and then 'Relay' or 'Ethernet to relay converter', as suited to how the relay is connected.
In the device settings of the relay, set the 'Default device state' to the position the relay must take when the mode cannot decide. The mode itself puts the 'Use case' of the relay to 'Direct passthrough of an external control signal' as soon as it is active.
