New Fox Battery & Hybrid Inverter installed over existing PV & Inverter

[DanielSP]

Hi All, good evening!

Sorry if I say something dumb, but my knowledge is close to 0.

I have just got a new Fox ESS Battery EP12 and Fox Inverter H1-5.0-E-G2-WL installed over an existing PV system 3.2kW with a Fox Inverter S3000-G2 and the values in the app don't make sense to me. The installers came today again, but it still showing odd values. Just to make it clear, the only PVs in the system are the original ones wired to the S3000-G2 inverter.

The origjnal inverter is in the loft and the new inverter + battery in the garage. In my app I can see both inverters and the battery. But there is a Gen Load information over the Solar that I'm not sure what it is.

Can someone PLEASE help me figure out and maybe I can share with the installers?

[evilbunny]

The origjnal inverter is in the loft and the new inverter + battery in the garage. In my app I can see both inverters and the battery. But there is a Gen Load information over the Solar that I'm not sure what it is.

Gen load shown in the app for me is from our original small solar system and a newer and larger solar system was wired directly to the new hybrid inverter and it reports separately as solar.

If it's showing at night like it seems to be, it could be the CT clamp monitoring it is connected to the wrong wire or is installed backwards.

Also you might want to delete the images you posted as your email address is showing and LLM AI is more than capable of collecting addresses that way to spam you later.

[DanielSP]

Hi, the only PVs in the system are the original ones wired to the S300-G2 inverter in the loft. The new installation is only battery and inverter.

[evilbunny]

Hi, the only PVs in the system are the original ones wired to the S300-G2 inverter in the loft. The new installation is only battery and inverter.

In that case it looks like you have 2 CT clamps on something, maybe the Gen load is the house load and was installed incorrectly and I have no idea what 1st would be monitoring as 44W used by the house is very wrong too.

[DanielSP]

Hi,

Yes, there are 2 CT clamps on the same wire, they say one for the original inverter and 1 for the new inverter. There is also another CT clamp outside near the meter.

[evilbunny]

Hi,

Yes, there are 2 CT clamps on the same wire, they say one for the original inverter and 1 for the new inverter. There is also another CT clamp outside near the meter.

The new inverter doesn't need a CT clamp to know what it's doing.

You might need to switch the CT clamp going to the meter as it shouldn't be gen load as that should be for another solar system so the inverter is probably confused by the inputs.

[DanielSP]

Hi, the installer came here yesterday.

He changed 1 CT clamp, the one generating the GenLoad value. He said that this CT clamp is to measure the Solar production, that he knows that since my original inverter is FOX and it's connected to the app, this clamp might no be needed, but he thinks it's better to have more info than less.

Therefore the current arrangement is:

1 CT clamp inside the distribution board for the original inverter to measure house load - this was already there before the new system

1 CT clamp inside the distribution board for the new inverter to measure solar generation diverted to the house

1 CT clamp inside the smart meter board for the new inverter to measure house load

Now the values for Solar and GenLoad are very similar all the time.

In my system, there is a complicator that any excess power generated by the solar after supplying the house goes first to the combi cylinder/boiler to heat water like a kettle. Only after the water is hot, then any other excess goes to the battery. I have isolated the combi boiler/cylinder to check and, when there is excess, the battery is now charging.

But I prefer ant excess solar to heat water because my daily consumption, even when there is no sun, is less than my 11.5kW battery and I charge for 7 pences (Octopus EV tariff)

What is your opinion?

[DanielSP]

[evilbunny]

battery. I have isolated the combi boiler/cylinder to check and, when there is excess, the battery is now charging.

That might be how your meter box is wired, because I had to stop our battery supplying our hot water tank, maybe it's not seeing it with the rest of the house load?

[DanielSP]

Hi, maybe because the battery is no supplying the hot water tank never. It only gets whatever is excess generated from the PVs after whatever the house needs. The hot water tank CT clamp is inside the smart meter box, outside the house.

[DanielSP]

Do you also have 2 inverters?

[evilbunny]

Do you also have 2 inverters?

Yes, the new Fox ESS hybrid inverter and an original system from the late 2000's.

The app/website only considers solar production from the panels connected to the Fox one, when pulling from the API feedin2 reports output from the other.

[DanielSP]

I see! In my case the installer said the value shown as Solar in the app is produced by the original S series inverter and the GenLoad value is measured by the CT clamp that feeds this value to the new hybrid inverter. Meaning that he could remove the CT clamp. The CT clamp is necessary when the original inverter is not the same brand. Your thoughts?

[evilbunny]

I see! In my case the installer said the value shown as Solar in the app is produced by the original S series inverter and the GenLoad value is measured by the CT clamp that feeds this value to the new hybrid inverter. Meaning that he could remove the CT clamp. The CT clamp is necessary when the original inverter is not the same brand. Your thoughts?

There is 2 related purposes for CT clamps on AC coupled systems, the first is so it can be monitored and excess power can charge the battery instead of being sent to the grid.

The 2nd and more important reason is so the hybrid inverter doesn't discharge too much to the grid at the same time and exceeds grid export limits.

The API returns cumulative totals, hence the min/max debug code. I just checked the portal and it does report a combined figure of 12.1kWh, but I haven't found an API that does. There is also the generation figure but I'm not sure what it is.

Code: Select all

variable: generation
min: 418.5kWh
max: 429.2kWh
diff: 10.7kWh

variable: feedin2
min: 96.2kWh
max: 99.2kWh
diff: 3.0kWh

variable: PVEnergyTotal
min: 345.3kWh
max: 354.4kWh
diff: 9.1kWh

and lots of API errors today too and at 1 point it wasn't reporting anything for today.

[DanielSP]

Sorry, I got lost here. Have you checked these values on your plant or my plant?

If there is problem at my plan, could you let me know what should I suggest to the installer for him to fix?

[evilbunny]

Sorry, I got lost here. Have you checked these values on your plant or my plant?

All mine, I can't access yours, I'm not a 1337 hacker lol.

If there is problem at my plan, could you let me know what should I suggest to the installer for him to fix?

I don't have a clue about wiring in other countries, but those that do, seem to post on here.

[DanielSP]

Thank you mate!

I'm monitoring my system and it looks right:

When there is no solar or not enough solar to supply the house, the house load is fed or partilally fed by the battery.

When the solar is equal or or bigger than house need, the house load is fed by the original inverter. Any excess is then diverted to the hot cylinder tank. When the hot cylinder tank is to the maximum or if I isolate it, the excess generation charge the battery.

I prefer the excees to be used by the hot cylinder because I can charge the battery for 7 pences/kW during the night and I do not need more power than the battery has.

I'll soon set the export to the grid. The idea is to export any load in the battery just before my cheap tarigg kicks in at 11:30PM.

[evilbunny]

I prefer the excees to be used by the hot cylinder because I can charge the battery for 7 pences/kW during the night and I do not need more power than the battery has.

Doing that saves on battery wear too.

I'll soon set the export to the grid. The idea is to export any load in the battery just before my cheap tarigg kicks in at 11:30PM.

It an interesting problem, and I'm still sorting the math out for my current plan so I don't charge too much or discharge too much due to the variability of solar production day to day.