FoxESS Community - Owners & Installers Forum

Today I've been testing the new grid meter compensation setting which allows you to set the inverter to always push back a tiny bit instead of drawing from the grid.

Thanks for the update Will.

I've had my system for less than a week and one of the first things I noticed was the constant grid usage of a tiny amount. This sounds great to solve that but I'm curious as to the technical reason why this happens? And why is pushing back to the grid a solution for it?

Cheers
Scott

Scott wrote: Tue Jan 14, 2025 11:11 pm This sounds great to solve that but I'm curious as to the technical reason why this happens? And why is pushing back to the grid a solution for it?

Cheers
Scott

The inverter is grid tied which means it has to syncronise to the grid and match the load power it measures on its meter/ct - it maintains a very small bias (current flow) from the grid (in self-use) and towards the grid (in feed-in) to maintain it’s syncronisation so that it can detect grid loss quickly and disconnect (by regulations).
I had a go at a more technical answer in this post if you are interested https://foxesscommunity.com/viewtopic.php?p=4135#p4135

Hi Dave,

Thanks for the reply.

I had a read of the more technical description you wrote, while some of it was beyond me its given me a better understanding of how it works.

I'm pretty new to solar, and I'm not particularly cluded up on electricity in general so it's great to be able to learn how it actually works.

Scott wrote: Wed Jan 15, 2025 9:29 am Hi Dave,

Thanks for the reply.

I had a read of the more technical description you wrote, while some of it was beyond me its given me a better understanding of how it works.

I'm pretty new to solar, and I'm not particularly cluded up on electricity in general so it's great to be able to learn how it actually works.

Hi no problem, and welcome to the world of solar.

You’ll be pleased to know I don’t often go that technical but the question of the slight power usage comes up regularly and in that case they were looking for a descriptive answer. This feature whilst quite small is quite a significant one for those of us that are trying to eliminate any power usage from grid

Is there any chance this will be made possible on the H1 gen 1 in the future? It always uses about 0.3kWh per day at the peak rate so it would save about £30 per year alone.

Here is hoping this new setting comes to the H1 gen 1 inverter. Particularly for the winter months as this small draw from grid often adds up to 300watts a day which over time really adds up. I manually set mine to feed in over night which helps reduce this but it's a bit of a pain to remember to do.

Is this update available for the KH10.5 and in the user settings? I would really like to get this enabled as the draw, although small, is annoying when trying to eliminate grid usage wherever possible. If I was to ask for the firmware update from Fox, presumably I'll still need to get the installer to alter the setting as I don't have agent access.

Today I got the latest updates from FoxESS on my KH10.5 and asked my installer to give me -20 watts. He knew what I asking for, and did it, but it has not made any difference (I have modbus, so can see grid use updated very frequently and I would notice 20 watts at the grid CT for sure). I also cannot find any reference to this setting after digging through the menu system on the inverter itself. Should I try a reboot? Any thoughts for me? Thanks.

UK_KH_User123 wrote: Wed Feb 12, 2025 6:12 pm Today I got the latest updates from FoxESS on my KH10.5 and asked my installer to give me -20 watts. He knew what I asking for, and did it, but it has not made any difference (I have modbus, so can see grid use updated very frequently and I would notice 20 watts at the grid CT for sure). I also cannot find any reference to this setting after digging through the menu system on the inverter itself. Should I try a reboot? Any thoughts for me? Thanks.

It’s not available through the inverter menu’s, only an installer level account can access this remotely.

I’m not familiar with this functionality but I know others have started with a setting of -50 watts and worked from there.

Strange .. not working for me. I had my installer change it to -50 and I still see it behaving just like it always did (typically pulling about 10 watt from the grid).

Master : 1.41
Slave : 1.01
Manager : 1.37

KH10.5

I've had the firmware updated and asked the installer to update the setting but it sounds like they need to get in touch with FoxESS for some reason. I'll keep you posted with how we get on. They're doing a site visit to install some additional slave batteries too.

Argh! I think I have found my issue perhaps. I was expecing to see a change in the Modbus entity sensor.foxess_grid_ct and there was no change. But actually, we are trying to 'calibrate' that sensor so that it is more accurate -- or we are trying to fool it into pushing back to the grid (that's what I'm trying to do and what Will was suggesting in his video).

I don't have an in-home display for my smart meter and don't have the special Octopus box that Will has so I can't see it. When my export figures appear for today on the Octopus usage history I can confirm if it's working or not.

I think it's working!

This looks really interesting and I'd like to change my setting but don't have installer access via Foxcloud. It is possible through the inverter screen interface and if so, could somebody point me in the right direction of which options to change? I had a look but it wasn't obvious to me and i didn't want to screw anything else up.

Thanks,

Phil

Phil M wrote: Fri Feb 21, 2025 9:57 am It is possible through the inverter screen interface and if so, could somebody point me in the right direction of which options to change? I had a look but it wasn't obvious to me and i didn't want to screw anything else up.

Thanks,

Phil

Sadly not, ask your installer (or Fox if unavailable) and they will change the setting remotely.

Here's what the meter compensation setting will look like - inverter's sensor.grid_ct figure compared to a Shelly CT. -30 set at 15:47:50. The inverter CT still registers +10W import, but the system is actually now exporting a small amount rather than importing a small amount. Of course it is the smart meter itself which is the most important measurement, and it is now hovering between 0 and 10W export, rather than importing about 20W.

Nice .. thanks for the pic!

Does anybody know if this option to set a small draw back to the grid is also available in the latest H3 firmware?

Hi everyone,

I have the H1 gen 2 inverter and would love to eliminate the constant draw from grid, which the Fox app suggests fluctuates between 5w and 25w. I've watched the video and don't have the same options in the desktop Fox setup, so I don't have installer access.

Could someone give me an idiot-proof explanation of what I need to ask for to achieve no background draw from the grid? I gather I need the installer to ask for updated firmware for the inverter, then to change a certain setting by a certain amount, but even having watched the video, I'm not technical enough to be confident I'd be asking for the right setting to be changed, let alone by the right amount. Also, can I ask Fox to do it direct? I have suspicions this kind of technical back end support might not be my installers' speciality

Thanks

Firstly you need to make sure you have recent firmware which supports the setting, then then you need to ask for the meter compensation setting to be changed to -30W

This is what I asked:

I would like to make use of the new KH Meter Compensation setting, to bias the grid pressure to export. Perhaps -30 watts. I have tried to locate this setting, but apparently it needs higher level permissions.

Do ask your installer first. It took about a week.

Note that the app will not show a change in import/export - it is the calibration of the CT clamp which is being deliberately biased, so when the inverter thinks you are importing 10W, it will actually be exporting 20W. So you need to see what the smart meter is registering (first check before asking, so that you know the 'before' figure). Once the change takes place, the smart meter should now be seeing the export, but the app will be seeing import.

Thanks WyndStryke - that seems very clear, will try the installer with that. My in-home display generally shows about 15-20w coming from grid as a background when not exporting, and correctly switches to showing the export symbol and amount whenever exporting, so hopefully it should be obvious when the background balance changes.

Installer came back instantly, telling me it's not their job and I have to call Fox. You've got to laugh at their continued insistence they have no responsibility for any part of the process!

Anyone had any luck going to Fox through the app to get this done? If I raise a ticket have I got any chance?

March wrote: Tue Apr 15, 2025 10:37 pm Installer came back instantly, telling me it's not their job and I have to call Fox. You've got to laugh at their continued insistence they have no responsibility for any part of the process!

Anyone had any luck going to Fox through the app to get this done? If I raise a ticket have I got any chance?

Yes, but it is supposed to be the installer's job. Make sure you identify the installer in the ticket and say that they're refusing to support it.

Long term, this might become a user-modifiable setting.

Just an update - after the installer engineer by email told me it wasn't their job to update firmware, I called the installers customer service phone line. Person on there said the engineer shouldn't have told me that, they must not know that it's their job to do aftercare, but that she could just call Fox and do it for me as soon as we came off the phone. An hour later, my in home display was showing a steady export of 5-15W instead of the constant import. Result! (Strangely the firmware showing in the app has not changed, but it appears not to matter)