FoxESS Community - Owners & Installers Forum

I have a 22 panel equal EW strings, H3-10 and EP11 battery (Three Phase).

I notice that as soon as the PV volts are 0, the battery stops DISCHARGING and starts topping itself up from the grid. I have the app set to Self Use and tried a few schedules, most recent being:

Midnight-23:59
Self-Use
Min SoC on grid 10%
Max SoC 10%
FDSOC 10%
FDPwr 10000W

Am I doing something dumb?

I've had the system a week and installer unable to get his head around the problem. Fox support being quite useless too.

I also notice, for example now at 10:15pm, Load, Grid PV and Battery all showing 0w usage. Battery is 100%. Sometimes load is a negative number too.

My aim is to use PV and battery and only buy from grid when battery is 10%. Battery to only be charged from PV (although will use cheap grid once our energy supplier switch is sorted).

That sounds very much like the installer has wired 1 or more of the phase incorrectly at the meter.

Being 3 phase your have L1/2/3 and these must be maintained throughout the system and particularly at the inverters meter (or it may be a meter with CT clamps in which case a clamp may be reversed) - but if you have phases swapped the inverter sees a load on a phase and responds on that phase - because the meter is wired wrong the inverters response is on the wrong phase and so you’ll see a negative load being reported.
Likewise it will get it’s metrics wrong and not use the battery properly discharging and charging incorrectly as you are seeing.

It’s a subtle fault and needs the phase wiring to be checked so that what the inverter is measuring as L1 is the correct way round and reading the correct L1 phase, rinse and repeat for L2 & L3.

I think thats a very good shout, thanks.