FoxESS Community - Owners & Installers Forum

excellent. then I set it as you told me 257.0. hoping that the Solaredge inverter will also hold up having activated the moving average from the assistance they call it. thank you very much

and nothing I have again grid frequency fault error ugh. I attach screen? the change of the 10min avg to 257 I imagine it has nothing to do with the frequency

I think you must be getting some very quick shifts in frequency that is tripping your inverter but they are not being recorded in the graph as the samples are 5 minutes apart.

The CEI0-21 standard tests with a lower limit of 47.5Hz (upper 51.5) so lets set the lower limit to that - in ‘grid para’ can you set your Fac1 lower to 47.5 then both of your Fac limits are set to the standard.

perfect thanks. set as you say after 2pm I'll take off from work thanks and I'll leave 10min avg as you say

perfect lower fac 1 set at 47.50 hz and I kept the 10min avg on 257 is everything correct? but one thing if I don't change the 10min avg and leave it at 253 it doesn't give me a frequency error in the evening, if instead I change it I from error

sorry for the many posts here I put the rfreq and rvolt graph and calculate that from around 12:00 I had 6 errors avg set to 253 (done yesterday because otherwise it would give me frequency error while I was using the batteries and I know it's not related but by setting it to 253 it doesn't give me a frequency error) now I put it back to 257 as you told me yesterday and set the DAC lower than 47.50hz

The 10 minute average should only affect your daytime running, the frequency error appears to be a night time thing - I thing what it shows is that your incoming grid power is sensitive to fluctuations.

Just change the fac lower 1 to 47.5 (and keep 10 minute average at 257v).

There are other settings that allow the inverter to respond more slowly to frequency changes but unfortunately you must have installer access and these settings can only be changed using an app and not in the inverter menu.

perfect so far everything is fine we will see this evening in the meantime thank you always for your time

this night everything was fine. 0 errors, but now at 12 and something here they are. Any ideas?

this night everything was fine. 0 errors, but now at 12 and something here they are. Any ideas?

Well, that's different again - this time it's a grid voltage fault - but it isn't a 10 minute fault, which tells me that we have the 10min set correctly but your grid voltage must have exceeded the inverters upper Vac1 voltage (checking back you said it was set to 262.2V which is correct)

The graph doesn't show the peak as it must have happened quickly and tripped the inverter - i'm assuming as it was close to 12 noon, it is a sunny day and you are at peak solar power that is driving this event.

Do you have any other equipment on your grid you can confirm what the voltage was - does your solar inverter have any voltage logs ?.

You can raise Vac1 upper slightly but i'm concerned that your voltage is starting to get very high - is high grid voltage a problem where you live ?

so, unfortunately I have old cables with a small section which when I input a lot go into overvoltage and don't hold up. The problem is that e-distribuzione doesn't change them unless they have knowledge. Another time at around 12pm I was inputting 3 into the network, 5kw (a bit of a cloudy day today for me) and from there the results are the 2 errors and then recover and go back up (at least that's what you can see from the solar edge graph of the first inverter). I don't have anything on the line to measure the voltage. I have never had any surges since I lived here in 2018. The system is new and compliant in every way (no wire joints or bridge sockets, cable cross-section, electrical panel, junction boxes, lines, sockets, lights, kitchen) and honestly I don't even know how. see it. the problem is that if I enter and maybe burn something to someone close to me and they check I can get into trouble, at least that's what he explained to me. Question is it better to have a 10min avg error or grid fault? because in this way I choose the least and I put the soul at peace ahahahahahahah.ah P.S i have ct meter from the main meter to the inverter now I don't know if to the solaredge or the fox ess
sorry but the upper va 1 was at 260.0v could that be?
and vac higher 2 at 264.5.

Ok that makes sense, if you have small section cables when the inverter is exporting the voltage will be much higher than the actual grid voltage.

The AC1 isn’t actually generating anything it’s just reacting to what the solar edge inverter is doing which because of your cabling must be allowing some fast voltage peaks and that in turn is causing your AC1 to trip - it’s unlikely you will cause any damage outside of your property as the grid voltage will be a lot lower when measured outside.

If you had installer access you would be able to control the amount of time before each voltage or frequency event is acted upon - this allows you to filter out any fast changes which would help here, but your installer could slow down the response times.

Unfortunately without installer access you only have access to the actual voltage limits - however because of your situation the AC1 isn’t itself generating the voltage, it is simply measuring what the solar edge is pushing out so you could try raising the Vac1 upper by another volt (to 263.2) and monitor it for a day or two.

if only my fox ess ac1-3.0-e inverter was compatible with the Solaredge optimizers I would avoid the Solaredge inverter itself (because this inverter also goes into overvoltage and disconnects) by connecting the panels and optimizers only to the Fox Ess inverter. Then I increase the vac to 263.2 and I'll see how it goes. Can I ask you another question? It's normal that during the night, let's say from 8pm, I use the batteries which for example, as in the attachment, the house requires 0.52kw and the batteries deliver 0.57kw and also takes from the 3w mains, meaning is it normal for the batteries to deliver more than what the house requires?
Thanks Dave for all the advice and for your time. Unfortunately I can't log in as an installer or administrator and whoever installed everything doesn't want to give me the credentials for the control

Ok, see how it goes, fingers crossed.

Yes that’s normal, the inverter is grid tied and remains syncronised by taking a small amount of power (a few W’s) from the grid.
The inverter itself takes a small amount of power to run, and converting the batteries power from DC to AC sees some losses as well, so not unexpected to see the battery power being 30-70W below the demand.

perfect thank you so much. I'll update you tomorrow if I can disturb you

here I am. so I get the usual grid voltage fault errors punctually when I enter a lot. at this point I really don't know. I'll leave it like this. cheerful screen

Just a couple of thoughts, there’s another way to manage this and suppress the high voltages you are seeing -

Your solar generation is at it’s peak around 12:00-13:00, you could delay charging your Fox batteries until 11:00, then the batteries will be charging throughout the solar peak time and that would keep the voltage low and stop it tripping.

Or you could set the Fox DC charge current to limit the battery charge to 1kW which would mean the batteries would charge slowly all through the day, but that would also keep your house voltage low and stop it tripping.

I'd rather have them charged from 12:00 onwards, but if it's sunny in the morning and then not, I find them partially discharged? Right? If I leave them like that instead and hope for a miracle of changing the cables (since I go every day to my e-distribution to bother them) could I suffer some damage to the inverter line or something else with that error?
However, if I were to choose to charge the batteries between 12:00 onwards (calculating that I have 15,300 kW of storage and I'm getting another battery in order to reach 18 kW of storage) how should I do it? Thanks

To delay charge until 12:00 onwards you will need to use the scheduler function, and so the first question, is your firmware up to date? - if it is, in the V2 app on the ‘plant’ screen the Quick Settings should have an option for ‘Mode Scheduler’ (if there isn’t you need your firmware updating).

You’ll have to create a schedule that sets the work mode to feedin-first at 7am, then sets it back to ‘Self-Use’ at 12:00.

Feedin-first should stop it taking any of the excess solar and will prioritise export, Self-Use is the normal use excess solar to charge the battery mode.

I’ve linked you to a colleagues wiki page, the wiki explains various work modes and the scheduler functions https://github.com/TonyM1958/HA-FoxESS- ... ork-Modes


If you want to throttle your battery charge current, it can only be done at the inverter in Settings, Battery, ‘Max Charge Current’ - the default value is 35A.

This is the DC charge current, so if you have 6 HV2600 batteries your nominal battery volts will be ~320V, and your charge current will be (320 * 35) = 11,200W but as this exceeds the size of your AC1 inverter it will set it to it’s max output.

You’re correct in that you could leave yourself exposed with part charged batteries if you have sun in the morning and not the afternoon, so setting the charge current to a level that gets you past 14:00 would be enough to suppress the high voltage you are seeing in the summer months.

If you want to restrict the charge to 1.6kW then you would set it to 5A (=5*320), if you want 2.2kW it would be 7A (=7*320) etc…

If you get another battery, that would really help with this as you could probably set it to 2.2kW which should be enough to suppress your voltage until 14:00

You could also leave it as it is, I don’t think you will cause any trouble to anything outside of your property but you are running quite high inside your house - again it’s probably not high enough to cause any damage but longer term it would be better to resolve the wiring to your house.

excellent. everything is quite clear. the extra battery is arriving this week reaching 7 and I think I will try to have them charged only from 11.. but 1 question do I have to reset everything with default parameters? even if I wanted to leave it like this with 1 error Like before I had a 10min avg error only. What do you think? Regardless, the first inverter always cuts out

No leave all the parameters the way you’ve set them, it’s quite safe and the frequency errors you were having are coming from your local supply grid so they need to remain as they are.

excellent. yes I have the latest firmware on board updated about 15 20 days ago by fox ess itself. at this point I think that as soon as I can I will follow your advice and program the schedule from 11 as you described.. one thing is not clear to me sorry. in the inverter in the battery branch which is set to 35a (following your steps) I bring it to 7a (since the other battery will arrive soon for a total of 7 batteries. right?

The battery charge current is the current in amps the batteries charge at, and that translates to charge power if you multiple amps * volts.

The 7A (amps) is not the number of batteries but the maximum charge current, with 6 batteries (320 Volts) your actual maximum charge rate would be 7 * 320 = 2,240 watts.

With 7 batteries your battery voltage would be ~ 373 Volts so if you set it to 6A your maximum charge rate would be 2,238 watts

You can always adjust the charge current up or down once you have a better feel for how long the batteries charge for.

Yes, I'm sorry, maybe I didn't translate what I wrote to you well. yes, I know that 5a 7a did not refer to the quantity of batteries but to the charge entering them. I just wanted to have confirmation (to avoid damage) in the battery charge section set by default at 35a I had to go down to 7a or 5a (but I prefer 7 amps i.e. Approximately 2.2kw of charge) I would prefer to leave it at 7a even when I have 7 batteries in order to charge with approximately 2.6kw (7x373). So I'll take 35a to 7a. Is everything correct?
Thanks for all