negative load causing battery to charge from grid?

[Shpmcf]

Hi,
Does anyone have any experience with this problem: We recently had solar panels and a Fox battery installed. When there is a high load, the Fox battery starts to charge off the grid, even though forced charging is off (disabled via both the "Force Time Charge" slider on the Device tab; and also the "Enable charge from grid slider" on the Edit Charging Time screen.) Initially it seemed that plugging in our EV to charge triggered this occurrence. However, other high draw appliances such as the dishwasher also triggers it. In all cases, the common denominator is that the load displayed on the Fox app goes negative.

We have two inverters (T10-G3 near the panels, and AC3-10.0-E near the battery and grid meter). Both the installer & Fox support say that with two inverter systems, the occasional negative load reading is normal and doesn't affect system performance. However, as noted, the negative load seems to be connected to the Fox battery starting to charge off the grid, which clearly isn't right.

Any advice would be much appreciated. Our system is 3 phase, and the equipment installed (working back from the PV panels to the meter) is:
PV panels
T10-G3 inverter
EML24 emlite
3 phase distribution board (near the panels)
3 phase distribution board (near the meter)
AC3-10.0-E inverter
CHNT 3 phase smart meter
Fox EP11 battery

Also attaching a screenshot of the app showing the negative load and the battery charging off the grid (it was dark so definitely no PV generation at the time). The trigger in this instance was dishwasher (EV was not plugged in).

Thanks!

[Dave Foster]

You shouldn’t see a negative load, it means that either the meter is not connected in the right place, or the phases have been wired out of sync (i.e. they should be connected as L1 = ‘R’, L2 = ‘S’, L3 = ‘T’). The result is that the inverter is unable to calculate the load correctly.

The Fox batteries should charge automatically in Self Use mode if there is excess solar without having to set a Force Charge.