Documentation

Automatic phase switching

From version 1.24.0, the cFos Charging Manager for cFos Power Brain wallboxes features automatic phase switching. If the available current falls below 6 A during three-phase charging, the cFos Charging Manager attempts to switch the wallbox to single-phase.

The standard allows the wallbox to signal a minimum of 6 A per phase to the car, below which it can only be switched off. If the solar surplus falls below 3 × 6 A × 230 V = 4.14 kW, the Charging Manager switches to single-phase. This means that single-phase charging is possible from 1 × 6 A × 230 V = 1.38 kW. If the wallbox is now charging single-phase and the surplus increases sufficiently, the system switches back to three-phase after a certain delay (can be set in the general Charging Manager parameters)

Even without solar surplus charging, the cFos Charging Manager switches to single-phase if there is sufficient current available on phase 1, but the available current on phase 2 or 3 is too low. If there is sufficient current on all phases again later, the Charging Manager switches back to three-phase. This is useful if there is little power available overall in the case of load management or if you have a large load on a particular phase. You can then connect it in such a way that (after phase rotation if necessary) this load is connected to phase 2 or phase 3 from the wallbox's point of view.

The cFos Charging Manager also supports phase switching via the "Charging Profiles" of OCPP, provided that the wallbox supports this. The cFos Power Brain Wallbox supports phase switching via Modbus and via OCPP.

Image Button 'Overwrite In the "Overwrite" dialogue, you can specify whether the wallbox is switched to single-phase or three-phase for the current charging process. This overrides the automatic phase switching.

For automation purposes, you can define a user-defined variable "switch_phases" with the following values in each wallbox set up in the Charging Manager: 1 = single-phase, 3 = three-phase, -1 = ignore.
The values 1 and 3 also override the automatic phase switching. This allows you to define your own formulas for phase switching using Charging Manager variables. The "Overwrite" UI has priority over the variables.

Phase switching by means of RFID

We have #thebestuser in the world! There was a request to switch the cFos Power Brain Wallbox Solar between single-phase and three-phase using RFID. Thank you for the idea of realising this with a user-defined output on the RFID card as follows:
Set up an RFID for three-phase charging in the user settings and set "Method" as the Charging Manager Output: GET and "URL" for this card:
http://localhost/cnf?cmd=modbus&device=evse&write=8087&value=0
For single-phase charging, you can set up an RFID card with Charging Manager Output "Method": GET and as "URL":
http://localhost/cnf?cmd=modbus&device=evse&write=8087&value=1
The prerequisite is that the wallbox runs as a master with activated load management.