Our very new installation is playing up, and we have 'G100 State 3' on the inverter. I read something about locking out so now panicking - Any ideas?
Here's what we've got:
Inverter: H1-3.0-E-G2 (Master 1.27, Slave 1.02, ARM 1.44)
Battery: EP5 (version BMS 1.004)
If relevant, we have what might be a separate issue but I mention it in case it isn't - When the battery is on, it sucks house load from grid instead of solar. Solar only seems to work to charge the battery, after which it stops generating and house continues to take from the grid. Beautifully sunny day here so this is very odd! If we turn off the battery, solar feeds the house no problem. Work mode is set to 'self use' and no charge settings are on.
Thank you in advance oh knowledgeable people!
Unless you have a reason to be set to G100 (like an export limit), I wouldn’t expect to see any G100 errors on a 3kW inverter as it is below the G98 limit and shouldn’t need anything special.
The state 3 means that your inverter has detected a parameter grid voltage, frequency, export power etc.. that is outside of the parameters set and it will shutdown until the problem disappears - it sounds to me as if your installer has configured this incorrectly, give them a call to check it out - as I said, I really wouldn't expect to be seeing a G100 on such a small system, and if it is set then the parameters are incorrect and need to be set correctly.
The state 3 means that your inverter has detected a parameter grid voltage, frequency, export power etc.. that is outside of the parameters set and it will shutdown until the problem disappears - it sounds to me as if your installer has configured this incorrectly, give them a call to check it out - as I said, I really wouldn't expect to be seeing a G100 on such a small system, and if it is set then the parameters are incorrect and need to be set correctly.
Hi Dave, thanks for your response and wisdom!
We do have an export limit- we aren't allowed to export at all to the grid currently (it's a very small grid on an island that isn't set up for this yet). So my husband set the maximum export power to 0 to prevent the export. I'm guessing these are the incorrect parameters you mentioned - we haven't been able to find instructions for setting this in the manual though - have you got a link? Or are we best talking to Fox?
Do you think this could be causing the battery problem too?
Unfortunately this is a semi-DIY situation - there's no installer on the island so we flew one over as a bit of a favour but he's had to go back now.
We do have an export limit- we aren't allowed to export at all to the grid currently (it's a very small grid on an island that isn't set up for this yet). So my husband set the maximum export power to 0 to prevent the export. I'm guessing these are the incorrect parameters you mentioned - we haven't been able to find instructions for setting this in the manual though - have you got a link? Or are we best talking to Fox?
Do you think this could be causing the battery problem too?
Unfortunately this is a semi-DIY situation - there's no installer on the island so we flew one over as a bit of a favour but he's had to go back now.
There’s nothing wrong with setting the export limit to throttle the export so that should be all good, but the G100 message implies you have the wrong safety code selected - set it to G99_UK and then with the export limit set to 0 it won’t export.
You are also on older firmware, if you have installer or agent access you can update these yourself the latest versions are -
Master 1.33
Slave 1.03
Manager 1.49
Update your Master first, then Slave and then Manager
On your batteries the firmware there is also a few versions old and as these are such new batteries I would recommend updating them to latest 1.007
You can also raise a ticket via the V2 app and Fox will update the firmware for you but make sure you ask them to update the inverter and batteries.
You are also on older firmware, if you have installer or agent access you can update these yourself the latest versions are -
Master 1.33
Slave 1.03
Manager 1.49
Update your Master first, then Slave and then Manager
On your batteries the firmware there is also a few versions old and as these are such new batteries I would recommend updating them to latest 1.007
You can also raise a ticket via the V2 app and Fox will update the firmware for you but make sure you ask them to update the inverter and batteries.
Hi Dave,
Thought I'd just send you my thanks.
We submitted a request for firmware update to Fox but they've not done anything (a week later) so we sorted the account and did it ourselves, along with changing to G99_UK and a hard reset after all that and.... it's working! Fabulous weekend of using the battery overnight and recharging through the day - very happy family here.
Thanks again!
Jo
Thought I'd just send you my thanks.
We submitted a request for firmware update to Fox but they've not done anything (a week later) so we sorted the account and did it ourselves, along with changing to G99_UK and a hard reset after all that and.... it's working! Fabulous weekend of using the battery overnight and recharging through the day - very happy family here.
Thanks again!
Jo
This message popped up for me today on my KH10.5.
The grid went down then back up again pretty quickly (within a few minutes) -- TWICE -- then I noticed the inverter was not taking in any solar power nor using the battery, it was just passing power from the grid to the loads (my loads are on EPS output).
Front panel of the inverter showed this G100 State 3 message. I checked and the inverter was still set (as always) in G99 mode, I have 10.5 kW DNO export approval.
I poked around a bit in the menus but the 'fix' was to power the inverter totally off and back on. A simple 'stop' / 'start' from the menu didn't do it.
I think in my case the message is not related to G100 but rather the inverter has been through some power issues recently and is unable to right itself without a reboot. Of course, this is not a good or expected outcome and hopefully can be fixed by Foxess.
I'm on Manager 1.37 / Master 1.41 / Slave 1.01.
The grid went down then back up again pretty quickly (within a few minutes) -- TWICE -- then I noticed the inverter was not taking in any solar power nor using the battery, it was just passing power from the grid to the loads (my loads are on EPS output).
Front panel of the inverter showed this G100 State 3 message. I checked and the inverter was still set (as always) in G99 mode, I have 10.5 kW DNO export approval.
I poked around a bit in the menus but the 'fix' was to power the inverter totally off and back on. A simple 'stop' / 'start' from the menu didn't do it.
I think in my case the message is not related to G100 but rather the inverter has been through some power issues recently and is unable to right itself without a reboot. Of course, this is not a good or expected outcome and hopefully can be fixed by Foxess.
I'm on Manager 1.37 / Master 1.41 / Slave 1.01.
KH 10.5
24 x 480w PV panels N/S
8x ECS4800
W4 Datalogger
Home Assistant via Modbus
Sussex
24 x 480w PV panels N/S
8x ECS4800
W4 Datalogger
Home Assistant via Modbus
Sussex
Site Admin
G100 State3 means one of things:
1. settings > 0000 > safety settings > grid code = make sure this is set to G99 and not G97 by accident
or
2. your grid voltage is exceeding the 260v limit and your inverter is shutting down to prevent damage to your inverter and your local grid.
If you can confirm point 1 is configured correctly, then in the cloud reporting check on the rVolt value and check it's not going over 252v+ if it's going into the 260+ volts then this is your reason for the issue.
1. settings > 0000 > safety settings > grid code = make sure this is set to G99 and not G97 by accident
or
2. your grid voltage is exceeding the 260v limit and your inverter is shutting down to prevent damage to your inverter and your local grid.
If you can confirm point 1 is configured correctly, then in the cloud reporting check on the rVolt value and check it's not going over 252v+ if it's going into the 260+ volts then this is your reason for the issue.
Community Admin / FoxESS Elite Professional
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3 x KH Hybird Inverters (Parallel Mode)
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32 x 490w across 4 arrays
2 x EV's (Tesla & Mercedes)
Heatpump & Low Carbon Housebuild
Did I help you? Feel free to leave me a tip Book a zoom meeting for remote consultancy or help Switch to Octopus and earn £50 Subscribe to my YouTube channel3 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1 (Solar Mode)
1 x H1 Gen2 WL (Testing, Modbus and API development)
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
2 x EV's (Tesla & Mercedes)
Heatpump & Low Carbon Housebuild
Hi Will:
I did confirm Grid Code was G99 on the inverter front panel.
The voltage and possibly frequency may have been a litte wonky for 10 minutes when the grid dropped and was restored twice. I didn't observe it to be high but it's possible it was.
I can say however that inverter power down and restart brought it back to normal operation. The unknown is whether normal operation would have resumed on its own once the grid seemed 'good' again without my intervention.
BTW, I did post a reply about the generator connection viewtopic.php?p=8600#p8600
I did confirm Grid Code was G99 on the inverter front panel.
The voltage and possibly frequency may have been a litte wonky for 10 minutes when the grid dropped and was restored twice. I didn't observe it to be high but it's possible it was.
I can say however that inverter power down and restart brought it back to normal operation. The unknown is whether normal operation would have resumed on its own once the grid seemed 'good' again without my intervention.
BTW, I did post a reply about the generator connection viewtopic.php?p=8600#p8600
KH 10.5
24 x 480w PV panels N/S
8x ECS4800
W4 Datalogger
Home Assistant via Modbus
Sussex
24 x 480w PV panels N/S
8x ECS4800
W4 Datalogger
Home Assistant via Modbus
Sussex
Site Admin
thanks for the follow up. I suspect the genny is going slightly out of G100 spec for a brief time.
Community Admin / FoxESS Elite Professional
Did I help you? Feel free to leave me a tip
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Switch to Octopus and earn £50
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3 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1 (Solar Mode)
1 x H1 Gen2 WL (Testing, Modbus and API development)
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
2 x EV's (Tesla & Mercedes)
Heatpump & Low Carbon Housebuild
Did I help you? Feel free to leave me a tip Book a zoom meeting for remote consultancy or help Switch to Octopus and earn £50 Subscribe to my YouTube channel3 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1 (Solar Mode)
1 x H1 Gen2 WL (Testing, Modbus and API development)
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
2 x EV's (Tesla & Mercedes)
Heatpump & Low Carbon Housebuild
Posting this a bit later, in case it helps someone with the same issue.
Our relatively new Hybrid inverter and battery installation got stuck with a G100 State 3 message (inhibiting battery discharge).
A power reboot did not clear this.
I found that there is a G100 sub menu under settings > on-line which included a reset option. On selecting this it changed from G100 state 3 to G100 state 1, and the Inverter home display then said "normal", and the battery discharge resumed.
Hope this is of help.
No clue why it went into state 3 in the first place.
Duncan
Our relatively new Hybrid inverter and battery installation got stuck with a G100 State 3 message (inhibiting battery discharge).
A power reboot did not clear this.
I found that there is a G100 sub menu under settings > on-line which included a reset option. On selecting this it changed from G100 state 3 to G100 state 1, and the Inverter home display then said "normal", and the battery discharge resumed.
Hope this is of help.
No clue why it went into state 3 in the first place.
Duncan
Unfortunately, we are seeing the G100 state 3 error on a fairly regular basis, requiring a G100 reset ( as I described above) every few days, or occasionally few weeks. The reset is always successful, and the Inverter reverts to "normal" state after the reset, but it doesn't last.
When in the G100 state 3 condition, the inverter will charge the battery but will not send anything to the grid/ house.
I suspect (don't know for sure) that it may be triggered by a high grid voltage - I know that our voltage is in the 245 - 250V range normally.
The question is what to do about it?
Our previous inverter (pre-battery) was a Kaco Powador which did not cause any problems.
I could ask the installer to replace the inverter, but I'm not confident this would help unless they change to a different make.
Any ideas welcome.
Duncan
When in the G100 state 3 condition, the inverter will charge the battery but will not send anything to the grid/ house.
I suspect (don't know for sure) that it may be triggered by a high grid voltage - I know that our voltage is in the 245 - 250V range normally.
The question is what to do about it?
Our previous inverter (pre-battery) was a Kaco Powador which did not cause any problems.
I could ask the installer to replace the inverter, but I'm not confident this would help unless they change to a different make.
Any ideas welcome.
Duncan
What Inverter do you have?
What firmware is running on your inverter?
Are you supposed to be on G100 or G98, G99 for example?
What firmware is running on your inverter?
Are you supposed to be on G100 or G98, G99 for example?
Hi
I have a Fox ESS 6KW Hybrid Inverter H1-6.0-E-G2-WL
master 1.40, Slave 1.04, Manager 1.26
It is oversized for our panels (2.4KWp on the original FIT) to allow for a possible future Heatpump upgrade. We have a bi-directional generation meter.
The solar panels were installed back in 2007 I think, but we "upgraded" to a battery system with this hybrid converter in Dec 2025.
Thanks for any advice.
I'm tempted to go and have a scroll round the menus to see if I can slightly increase the upper voltage thresholds.
I have a Fox ESS 6KW Hybrid Inverter H1-6.0-E-G2-WL
master 1.40, Slave 1.04, Manager 1.26
It is oversized for our panels (2.4KWp on the original FIT) to allow for a possible future Heatpump upgrade. We have a bi-directional generation meter.
The solar panels were installed back in 2007 I think, but we "upgraded" to a battery system with this hybrid converter in Dec 2025.
Thanks for any advice.
I'm tempted to go and have a scroll round the menus to see if I can slightly increase the upper voltage thresholds.
There does exist some firmware updates for your system, not saying that this is a cure for the error.Duncanm wrote: ↑Sun Mar 22, 2026 1:34 pm Hi
I have a Fox ESS 6KW Hybrid Inverter H1-6.0-E-G2-WL
master 1.40, Slave 1.04, Manager 1.26
It is oversized for our panels (2.4KWp on the original FIT) to allow for a possible future Heatpump upgrade. We have a bi-directional generation meter.
The solar panels were installed back in 2007 I think, but we "upgraded" to a battery system with this hybrid converter in Dec 2025.
Thanks for any advice.
I'm tempted to go and have a scroll round the menus to see if I can slightly increase the upper voltage thresholds.
viewtopic.php?p=8069#p8069
If you are to make adjustments yourself, please take pictures of before/after for your own records (and to restore settings if you made an error)
As you have a 6kW inverter, have you been given a G99 certificate for operation?
Hi
further update, after a scroll around the inverter menus
The Safety mode is set to G99_UK which I think is correct.
The Vac upper 1 is already set to 262.2V and can't be increased by more than 0.1V (update fails).
Looking at the error log (in History), there are a few "meter lost" errors, one grid frequency error and one grid voltage error all within the last week or so.
Our CT connection is wireless from a remote meter/ CT, as the inverter is not adjacent to the grid supply box/ smart meter etc.
further update, after a scroll around the inverter menus
The Safety mode is set to G99_UK which I think is correct.
The Vac upper 1 is already set to 262.2V and can't be increased by more than 0.1V (update fails).
Looking at the error log (in History), there are a few "meter lost" errors, one grid frequency error and one grid voltage error all within the last week or so.
Our CT connection is wireless from a remote meter/ CT, as the inverter is not adjacent to the grid supply box/ smart meter etc.
Hi
thanks for the info re firmware. I think it makes sense to upgrade to the latest. It seems a bit odd to me that there is no automatic way for this to happen, apart from the user contacting Fox or the installer.
I'm not aware of receiving a G99 certificate. I left all the paperwork side of things to the installers.
I did have some communication with the FIT payment provider (EDF) to ensure they were happy with the switch to a hybrid inverter and battery, which they are so long as the gen meter is bidirectional.
The system is working OK at the moment, but next time it latches off with G100 s3 I will check the History to see what might have triggered it. It seems a bit poorly thought out to me that the system latches permanently into this state after a grid error, and does not recover when the grid is back in tolerance. If this happened whilst we were away, we would lose our FIT payments until we were back and noticed the issue. Hmm... maybe I could see it in the App and contact the installer. I'm not sure if they could reset the G100 error remotely.
It may be that our local grid does transiently go out of tolerance for either voltage or frequency, but there's nothing I can do about that. Our previous inverter (Kaco Powador) did not suffer from this.
This is all a lot more "hands on" than I expected.
Thanks for the input.
thanks for the info re firmware. I think it makes sense to upgrade to the latest. It seems a bit odd to me that there is no automatic way for this to happen, apart from the user contacting Fox or the installer.
I'm not aware of receiving a G99 certificate. I left all the paperwork side of things to the installers.
I did have some communication with the FIT payment provider (EDF) to ensure they were happy with the switch to a hybrid inverter and battery, which they are so long as the gen meter is bidirectional.
The system is working OK at the moment, but next time it latches off with G100 s3 I will check the History to see what might have triggered it. It seems a bit poorly thought out to me that the system latches permanently into this state after a grid error, and does not recover when the grid is back in tolerance. If this happened whilst we were away, we would lose our FIT payments until we were back and noticed the issue. Hmm... maybe I could see it in the App and contact the installer. I'm not sure if they could reset the G100 error remotely.
It may be that our local grid does transiently go out of tolerance for either voltage or frequency, but there's nothing I can do about that. Our previous inverter (Kaco Powador) did not suffer from this.
This is all a lot more "hands on" than I expected.
Thanks for the input.