FoxESS Community - Owners & Installers Forum

Hi,
I've just retrofitted a new Fox ESS battery, with 3 phase inverter AC coupled to my current PV solar array and Sungrow inverter.

Generally all is work fine in reality.
Real-time live power data is accurate (with regards to magnitude, not sure about direction of power).

My problem is with the cumulative Load value when I look at the day by day data. It's represented as Load(-) and I understand this means that I have a 3rd party PV solar array producing abundant energy (which I do).

It just seems that the Load(-) is calculated by = Grid(export) + battery charge - battery discharge. There's no other variable there.

Live data displays Meter2 curve accurately (but is in the 'usage' area under the horizontal line).

Installer came and out and is happy with all the CT clamp placements (he mentioned I have 6 as I have 3 phase).

I attached screenshots. Any ideas? Is this just an app data read issue because my system is AC coupled?

A second inverter source usually messes up the load figure even on a single phase inverter, the CT2 clamp placement and phase direction are critical to the calculation that takes place in the Fox cloud.

I believe that the calculation it is doing is Load Power = GridConsumptionPower + Output Power(RST) – FeedinPower + meter2Power

But sometimes with 3 phase systems the sign of meter2Power is reversed, in which case the actual calculation would be better represented as Load Power = GridConsumptionPower + Output Power (RST) – FeedinPower + abs(meter2Power)

But just a thought, have you tried the Energy Stats app ? - Al the developer added an optional setting that allows it to flip the sign of meter2 for 3 phase systems which worked much better.

But in all honesty the best advice is to install a home assistant and then do your own load calculations based on the R/S/T values for CT1 and meter2 and feed those into an integral to produce your energy statistics.

Hi Dave,

Thanks for very much, that's very helpful information and reassures me of my own theories of what was happening.

I'll give the Emergey Stats App a go first.

RE Home Assistant, how do I go about this?

DrChubs wrote: ↑Thu Jan 08, 2026 11:39 pm RE Home Assistant, how do I go about this?

On the Home Assistant, Will has done a useful video here https://youtu.be/kE_6HtzcyXg?si=b0UZJZm5aYUwRyHo

There are 2 options, using the OpenApi (‘Fox Cloud’) which is easiest but only gives you access to 5 minute data samples and no control of the inverter, the slightly more difficult option is the modbus route which requires an RS485 adapter but if you have an H3 Smart, you can directly connect to it over LAN - this option gives you near real time access to all sensors and totals as well as local control of the inverter.

You can buy a Home Assistant Green which is basically a pre-made mini cpu (raspberry pi based), it’s ready to go and just needs you to add the cloud or modbus integration and then you can do whatever calculations using template sensors or create dashboards that show your data - it’s quite the rabbit hole but well worth the investment.

Again, very helpful. Thank you.