FoxESS Community - Owners & Installers Forum

Hey,

I’ve have recently had a solar power setup installed which includes a T8-G3 Foxess inverter. Looking at the fox cloud dashboard I see that the solar panels are generating power, and seemingly sending all of it to the grid. According to the dashboard the house load is permanently 0, as is the draw from the grid.

That doesn’t seem correct.

I have no idea where to even start with diagnosing this. I will contact the installer and ask them what’s up.

But in the mean time, I thought I’d ask here:

Are there any obvious installation steps that might have been skipped?

And mostly for my own curiosity, how does the inverter get access to the load/grid usuage data in the first place?

The inverter usually has a current clamp connected to the live wire coming into your property, telling it how much power is entering / leaving. It sounds as though this either not been installed (which would be a pretty serious oversight to be honest) or more likely, not connected up properly - or one of the fairly thin wires that connects it to the inverter might have broken during install.

Definitely an issue to go back to your installer about. Should be an easy fix for them.

Thank you! I will bring this up when I talk to the installers.

Another newbie question for you: How is the actual usage of grid power versus solar panel power governed? Is it by this managed by the inverter somehow, or is it somehow balanced automatically elsewhere?

I have no idea right now if we’re actually using the power we are generating, and realising that not only I have *absolutely* no idea how this works at a fundamental level, I don’t even know how to ask intelligent questions.

Once upon a time when you "got solar" you had the panels on your roof, and an inverter that converted the high voltage DC current from those panels into mains voltage AC that your house could use. You either used the power as it was produced, or it went out onto the grid and powered something else. If you wanted to maximise use of the solar, you needed to run your major appliances when the panels were producing.

If you don't have a CT clamp then the inverter sees no power coming or going, and hence you see a flat trace on the website. Electrically, I think that you must be using some of the power, because if your panels are producing some amount of power your house will be drawing less from the grid than it otherwise would be.

If you have a battery system (and you don't mention if you do have a battery or not) then the inverter can be instructed to prioritise charging the battery, or servicing the load in the house, or even exporting to the grid. Essentially there is logic in the inverter that controls where the power from the PV (and battery if present) goes.

How do you prioritize export over charging?

Not that I want that, as it cost me a penny more to import than I get for export. But I do see some tariffs where the peak payment for export is greater than minimum cost for import, and it makes some sense to prioritize, even force export in that high export payment period.

Graham

At least on the H1 inverters, there is a workmode called Feed-In First, which as I understand it, will export "spare" PV (ie not being used on site at that moment) to the grid rather than charging any batteries that may be connected (see section 8.2 of the manual here).

Looking at the installation manual for the G3 inverters, it doesn't look like there's any mention of a CT clamp like with the installation guide for the inverter just posted. Anyone know what's different there?

Looks like the G3 uses a meter rather than a CT clamp to measure current going in and out (see section 6.3). @Lingmops, I'm not sure exactly which one you'd need, something to talk to your installer about.

EDIT: At a wild guess something like this ? https://www.acrel.uk/acr10r-energy-mete ... erter.html

The installer just got back to me and said: (paraphrasing) “You need a smart meter to get that data, and we don’t provide those. Tough luck.”

So I guess I have to figure this one out without them

At a guess, something like this https://www.eastroneurope.com/products/ ... modbus-3k7 could work, it would need to be wired into your incoming supply and also connected to your inverter, but that should then let your inverter "know" and log how much energy is going in or out.

The wiring itself would be straighforward for any electrician, but you might want to find a supplier and give them a call to double check suitability before buying. I have no affiliation with or knowledge of these folks https://aphex-metering.com/product/east ... -v2-meter/ for instance, but that's the kind of company I would call for advice (in the knowledge that I'd feel honour bound to buy whatever device they recommended in return!)

According to manual I found its a 3 phase inverter and only works with a meter.

Does that make sense ie do you have three phase power at that location?

is there any wifi energy smart meter which can be attached to Foxess On-Grid inverter T15-G3?

alpino wrote: ↑Mon Mar 25, 2024 3:33 am is there any wifi energy smart meter which can be attached to Foxess On-Grid inverter T15-G3?

There is no wifi meter available for the Fox equipment, but you can use the normal Chint meter and connect the RS485 via LORA - this module has been tested and works with the T series USR-LG206-L-P - link here https://www.pusr.com/products/serial-rs ... 206-p.html