First 30 to 45 seconds of the session, charger is trying to discover minimal and maximal charging current for connected vehicle. Actual time depends on the connected car - how fast it reacts to the PWM signal.
Charger is rising target current until vehicle stops accepting it
At the beginning of the charging session, charger is increasing target current up to the lowest maximum for the charger (EVSE max current, Cluster limit, Modbus limit).
If chargers sets target to 10A and vehicle accepts that target (starts charging with 10A) charger will increase target to 11A. If cars accepts 11, charger goes to 12…
When charger reaches any of above mentioned limits, and car has followed it, then charger will later again try to discover new vehicle max (only if some of the limits are changed during session).
In case that vehicle stops accepting target new currents (stays on 11A while charger is offering 12A or more) then charger assumes that it is actual vehicle max current and will not repeat vehicle max discovery.
Using external power management?
In case when you don’t use internal power management just disable power management on the charger’s web UI and charger will continue to discover EV max current but will not use it as limitation. Only station power management uses that value for it’s own calculations.