FoxESS Community - Owners & Installers Forum

My system uses an H1-11.4-US

This is a grid tied inverter with no batteries.

The system needs to limit its total power pushed back onto the grid to be limited to 10.1Kw, as dictated by the utility company

For this reason I have installed the current transformers as directed, on the input from the Utility Meter where they would measure total current flow to and from the Grid.

I installed the current sensors on at the connection to the grid, because I want the inverter to provide the power to the cabin and only limit the inverter to what was allowed to be pushed to the grid after the cabin is supplied.

The inverter is connected into the main panel through a 60A breaker

When there is no solar generated, load and grid power are identical. The load is say 1Kw (Showing as red and negative) and the grid supplies 1Kw (Showing as blue and positive). The is typical consumption for this cabin.

However, as solar production increases (in the morning, after dawn for instance), the values of load are altered by the amount of solar being generated, even though the load had not changed.

For instance, when the solar is producing 5kW, the load shows as -4kW (now on the opposite side of the graph), which is the nominal 1kW load being consumed by the cabin minus the 5kW output that is being supplied by the solar panels.

Because the current sensors are on the utility meter, they are measuring net load (Cabin load - Solar supply)
So this throws off the actual cabin load value by the amount of solar being produced.

This error doesn't just affect the graphical display, but all other values for the day and accumulated values.

It seems to me that if the Inverter doesn't know its own power output without those current sensors, then it needs to measure its own output. Then it could measure Total output to the grid (which it needs to be compliant) and total output from the Inverter. By subtracting the two it could then know Cabin load.

The system needs to report both load and solar generation as separate and correct values.

Has anyone also seen this behavior? How do I go about properly setting that up?

You mentioned current sensors (plural), can I just check this is a single phase system, and that there are no other external generation sources in the cabin - in which case I would only expect CT1 to be connected.

Also any chance you can post an image of the load/grid traces

Hi Dave, thanks for responding.

The system is a 240V system, so two 120V lines to Neutral and single phase across the 240V lines.

So there is a pair of current transformers on the utility lines coming in to the panel. (see picture)
Based on the installation manual, I believe that the arrows are in the right direction.

A picture from the App shows how the load seems to be tracking the solar power generated
Load should really have stayed at a pretty constant 1kW

UPDATE:

So I reached out to my supplier (Solar Power Store) and posed the same question to them.
They reached out to Fox right away and had a few things sorted out.

They updated my inverter (which I believe fixed another issue of only PV1 being online - different discussion)

They also went into the Admin settings and adjusted R&D (Debug Meter) and reversed the connections on the Current transformers.

Now it all seems to be reporting properly, going forward in the Web app.
However, data in the Iphone app is still not quite right. Load is reporting above the 0 line, not below.
Also, previous data is still wrong - my guess is they cant fix that.

See the last two images comparing the web app to the iphone app

So its close, but not quite right yet.