The SOP is State of Power (similar to SOC - state of charge, SOH - state of health).
It is displayed at the main screen of Accelev EVSE electric car charger.
It depends on the quality and capability of your power source (home grid).
It will alarm you, when your grid may fail or connection is bad (not only at the charger, just whole electric network in house or garage).
The SOP uses an electric car as a load to proof the grid and is calculated as:
- (voltage drop per kilowatt charge power)*(250/voltage at the start)
Smaller values = better energy source.
It will change slowly intentionally. But charger will detect an unexpected increase in SOP as potential damage/failure of a network. So chargers will be able to detect ageing of cables, sockets, plugs, bad contact, water penetration in home grid etc.
3-4 very bad, consult your electrician
4+ do not use this grid for car charging, consult your electrician