FoxESS Community - Owners & Installers Forum

Hello. The timing was not ideal but we went away on a pre-booked holiday 5 days after the installation on September 9th. I’ve been looking at the app while we’re away and I don’t understand what appears to be going on with the system.

The screenshot below shows zero PV output (it being dark) and zero load (house being unoccupied) but electricity being exported! I assume this is coming from the battery?

If I was being paid for it, I suppose it could be a feasible option during a holiday, say, but I’m not set up yet for paid export, and anyway it's not an option I consciously chose or would choose.

Advice would be welcome, preferably in layman’s terms as I am not at all clued up on solar energy yet, although I want to be.

Hmmm, that doesn't look right. I would expect to see some load even with an empty house and normally a few watts at least. Is it possible the system can tripped a circuit breaker?

Hello Will. I don’t think a fuse has tripped as I have seen load on other occasions (fridge/freezer was left on). In fact, that’s my second point of confusion, as the daytime load and PV output seem to be in sync, in the sense that they are “mirror images” for want of a better description. As one goes up, so does the other. See attached daytime graph.

What does it suggest to you?

Have you set any schedules or charge times ?, the strange thing is the battery is discharging the moment there is solar generation and as soon as the sun goes down it’s gradually charging again which is the reverse of what you would expect.

It looks to me as if the CT clamp might be reversed (a common enough problem at install) - when are you back home? as it would be good if you could check it (we can guide you if you can post a few pictures of the CT location and orientation), or get your installer back to check it for you.

Hello Dave. We’re not back till the end of October, but one of my sons might be able to check it out. Trouble is, he’s up to his neck in his own domestic affairs so I certainly won’t pressure him!

He’s got an engineer’s mind though, and in fact mentioned the same thing as you about “CT Clamps” ( he explained what they are, he’s recently had a PV installation).

I’ll get my other son to go up into the loft and take pictures. He's not so practical but at least he’s got more time! Can you explain where these CT clamps might be located and what they look like?

It’s OK, I’ve googled CT clamps, Current Transformer, eh?!

The CT clamp is a simple clip on device that measures the ‘induced’ power flowing through a cable, the inverter uses it to calculate the load and when there is no PV it will match the battery discharge to the load power and it knows that when it’s a zero sum the load is being met fully from the battery.

When there is PV generation, the inverter can then balance the load, battery and PV power to meet the operating mode - normally self use i.e. PV covers the load first, then charges the battery, and when the battery is full it will export to grid.

I’ve attached a couple of images that show the CT clamp - which should be fitted on the live output of the smart meter - if you have an EV charger it might be a bit more complex as it usually splits here to power the house consumer and the EV consumer unit.

If your son can locate the CT clamp in the meter cupboard, it needs to be unclipped (just prise open the tab) and it will open - it has an arrow on it so you can see it’s orientation and it needs to be flipped through 180 degrees and clamp it tight again.

The app should then show your load as a positive figure (probably not much as you’re away) if there is no PV and there is charge in the battery it will be used to power the house, if there is PV generation you should see the battery charging.

If there’’s any doubt if he could take a picture of where the CT clamp is and a wider shot so I can see all the cables in the meter cupboard I should be able to advise from there.

Hello again. I’ve attached the pictures sent by my son. The arrow wasn’t very clear so they edited the shot. Apparently there’s an “L” at the head of the arrow and a “K” at the tail end (all embossed).

Further thoughts appreciated.

I was expecting to see a white CT clamp - i'm wondering if that is for a EV charger as they are almost universally back - do you have an EV charger fitted ?

I can see the live feed from the smart meter is going into a Henley block and splitting which is what usually happens with an EV charger - if you do then the CT clamp may have been fitted in the consumer unit itself in which case i'd wait to you get back and get the installer out.

But for now as you are charging from grid and then dumping it back without getting paid, i'd suggest that in the app you raise your Battery Reserve Capacity to 100% then it will stop that cycling and hold the discharge.

Hi Dave.

Was the CT Clamp wired the right way?

No there’s no EV charger in the installation.

I can’t change the Battery Reserve Capacity, there’s a message, something about it being beyond the configurable range. I did manage it earlier but now its gone back to zero

I’m getting less and less sure about anything!! Hopefully the installer will be back next week (my son will let him in). Does the CT Clamp have to be white? What’s wrong with the black ones?

Thanks for the advice given so far.

They are all essentially the same thing just a coiled transformer - the Fox one is unique in that it’s normally white but your installer may have used a different brand so as long as it meets the same ratio and output specification it will work ok.

The clamp is normally fitted to the live cable coming out of the meter, whereas this has been fitted to the incoming live - that’s ok but when fitted there the arrow should be pointing towards the grid, and yours is pointing towards the meter (it’s the wrong way round).

If your son is feeling up to it, ask him to open the clamp and reverse it’s direction, then see what your load/export/battery trace now looks like.

Morning Dave. They turned the CT Clamp round as you advised. I’ll post a pic of today’s graph a bit later. Hopefully you (and Will) will confirm that it looks more normal.

Re: the black/white issue, might the black clamp be designed for a fatter cable? I ask because on mine it looks like the xabke isn’t clamped tightly, and it passes through at an angle. I think I’ll get the installer to fit a white Fox clamp next week.

Thanks again for your input, much appreciated

Sorry about the typo, I expect you translated it to “cable” ok.

RogerC wrote: ↑Fri Sep 27, 2024 9:45 am Morning Dave. They turned the CT Clamp round as you advised. I’ll post a pic of today’s graph a bit later. Hopefully you (and Will) will confirm that it looks more normal.

Re: the black/white issue, might the black clamp be designed for a fatter cable? I ask because on mine it looks like the xabke isn’t clamped tightly, and it passes through at an angle. I think I’ll get the installer to fit a white Fox clamp next week.

Thanks again for your input, much appreciated

Ok, thanks - let us know how you get on.

No they are all the same size. It’s just rating i.e. 80A/40ma vs 100A/33ma - so as long as that cable CT clamp meets the same specs (it should be a ctsa016 100A/33ma) there’s no need to change it, I know they make a black version, just never seen one so far on Fox.

So it doesn’t matter if the cable is a loose fit in the clamp?

RogerC wrote: ↑Fri Sep 27, 2024 11:56 am So it doesn’t matter if the cable is a loose fit in the clamp?

No, it works by the voltage that is induced by current flowing through the cable and exciting the transformer coils, the space for the wire, the thickness of the wire or the angle it passes through make no difference to the result.

Now that the clamp has been refitted correctly and the inverter finally has correct information to go by, I’d like to know how to adjust the settings so that when there’s no PV output and the battery is charged, the load is met by the battery rather than the grid as at present (see attachment)

That’s looking much better now and reading correctly.

On that screen if you click on Quick Settings Here, then click on System MinSoc and set that to 10% and confirm, then click on Battery System Reserve and set that to 10% and confirm. Also double check that you have no charge times set.

It should then start using the battery to run the house.

Morning Dave! I tried to do as you suggested but I just get the error message you see in the attached screenshot.

I couldn’t see Battery System Reserve, did you mean Battery Reserve Capacity?

I’m so grateful for your assistance, I’m afraid the so called service department at foxESS has been useless, if their (lack of) response to my emails is anything to go by. Very disappointing.

Also, while I’m getting things off my chest, the forum website isn’t the friendliest, in a technical sense. I’ve taken to writing these messages in my email app then cutting/pasting them onto the forum website when I’ve finished, because I have so often lost contact with it part-way through, thereby losing all my work in progress, had to sign back in and start again. I think it’s because I’m getting bombarded with irritating intrusive adverts which disrupt the actual forum content really badly. I’m hoping it will be better when I get back to England.

Ahh ok, that looks strange, as if your battery has lost comms - which isn’t very common but with the new install and the problems you’ve had perhaps not surprising.

Just to double check it’s not an app problem, could you log into the foxesscloud.com (this may not be easy if you are doing this on your phone whilst on holiday) - on the left hand menu click ‘Device’ and then ‘Inverter’, it will show all the inverters in your account - on the right hand side click the button under ‘operation’ that will show a screen that looks like this -

Click on where the ‘red’ ring is, and that will open your battery settings - it should populate it with your current settings and if it does set the 2 minsoc’s at the bottom of the page to 10% and then press ‘save’

Unfortunately if that doesn’t work the next step is really a full system restart but with your installer coming next week perhaps the best thing to do now is wait for him to address it.

Just in case your son is going anyway, the restart process is to turn off the PV isolator to the inverter, then turn off the AC isolator to the inverter, on the batteries is a power button, press that to turn off and next to it is a battery isolator switch open that. Wait for a minute and the inverter display will go blank.
Then reverse the process, close the battery isolator, press the battery power button, close the AC isolator to the inverter and then close the PV isolator to the inverter after a minute of ‘checking’ it will go back on-line.
(There is a video in the guides section that would help with this)

Fox ESS are usually pretty good in replying if it’s something they can diagnose and rectify or for firmware updates, but they expect your installer is first point of contact for installation problems.

Hmmm I can’t disagree with the adverts, they are very frustrating for me as well, but this is all provided independently of Fox free of charge, as is the time of the community members and so every little helps in paying towards the costs of providing the forum.

I’ve tried to login to the website but when I input the sign in details it just comes back with Error 5xx. I checked my username on the app and changed the password successfully beforehand.

I’ll get my other son to try logging on as me in case it’s because I’m in Spain.

I did as fox asked and contacted my installer, but all he said was “It’s working” which I reported back to fox, thereafter silence.

Which makes me very grateful for this forum, which I would happily pay a subscription to. I suppose there’s a way of suppressing the unwanted ads, it was a problem in the uk for quite a long time but has now become much less so.

The house appears to have gone “Off Grid”. It it because I’ve been trying to use the fox website?

But I’ve now managed to login to FoxESScloud.com on my phone. HELP!

But I’ve managed to login to FoxESScloud.com on my phone. Where do I go from here?

It’s not anything you’ve done, the wifi datalogger on the inverter has lost it’s connection to your home router - don’t worry about the system it will continue to operate even without a connection.

I did wonder with you not getting your battery settings if the wifi signal at your inverter may be weak as trying to set the battery soc’s needs an immediate direct connection.

Assuming your house router is still ok, it may come back on it’s own - if it doesn’t restarting your house router is the first step, but if that doesn’t bring it back then the full restart on the inverter should re-connect it.

Sorry that your having this stress whilst you are on holiday but just to re-iterate your system will keep working now that the CT is in the correct orientation, any solar during the day will be used to cover your house load and charge your batteries even if they are not being used during the night.