FoxESS Community - Owners & Installers Forum

Hi,

We recently got the following installed

20x 600w panels
8x 2500kwh batteries
H3 12kw 3 phase inverter

We pretty much have the entire house connected.
When solar is available use that, then battery (30% reserved) then grid.
My question is related to the following.

During the day we can easily pull 4-5Kw per phase and we have no problem.
Two of the phases are more heavily loaded than the third. The most I have seen been pulled in total is 9.2kw.

Twice now in the evening the inverter has gone into overload protection when we generally have less activity in the house. Installer is saying the system can only handle 4kw per phase and we overloading it.

I have two problems with that statement :
1 - I am pulling daily more than 4kw on one phase during the day without issue
2 - The H3 datasheet seems to imply that the inverter can supply one phase up to 6kw max and have the remaining two phases share the other 6kw. This is regardless of the grid or EPS driven.

Something does not make sense. What am I missing?

If you are seeing overload i’m wondering if your inverter is wired for your load to be in EPS mode i.e. if the grid fails the inverter continues to provide power seamlessly, when it is wired in it’s normal operating mode you would expect any overload to be met by the grid and the inverter would simply provide it’s maximum power on that phase without an overload condition.

You can see the different wiring modes in the manual here https://www.fox-ess.com/download/upfile ... 250107.pdf - if it is wired for all the home load to be on EPS all of the time then it does have limits. The install could have normal home loads on the inverter with protected loads (i.e. things you want to keep working on grid failure) on EPS, or as is often the case there is an EPS box that allows the system to run normally until the grid fails and then it changes over to the EPS output (this mode means you have no load limits unless running on EPS).

As to the rated output, the H3 does have a limit, from what I can see looking at the datasheet - in normal mode (per phase) it has a max current of 19.2A but is rated at 17.4A i.e. at 230V that would mean it is rated for 4002 watts continuous, with a maximum operating of 4416 watts - but if you are running in EPS mode that is slightly higher at 22.7A per phase i.e. at 230V it can supply 5221 watts.

Can you confirm how your system is wired ?