FoxESS Community - Owners & Installers Forum

Hi all

I've just had a KH10 and 42Kwh battery installed but seeing signs already something may not be right with the install.

At a glance, the battery hasn't discharged once (other than small amounts) over 3 days, despite our house definitely using power when we're no longer generating solar. In addition to this the house load seems to just follow the solar panel generation - during the day it shows us using 4-5kwh, and at night it shows us using 0.

I've checked CT clamp settings and it's definitely enabled, changing the reverse setting makes no difference as well.

I'm wondering if the CT clamp or the internal meter mechanism of the inverter is faulty? The somewhat smoking gun in all of this is that the meter device in Fox ESS cloud has never shown values above/below 0.01kw, so makes me think that just isn't reading load correctly at all

The one puzzling part is that yesterday after a restart of the inverter and reseating the CT clamp plug into the inverter, the inverter itself showed data that made sense (2kwh being generated by panels, 600w battery discharge, nothing from grid), but then inevitably returned to usual illogical data.

Has anyone seen this before and have any ideas I could try while I try and organise for the installer to come back out?

Have added pictures here showing meter data and the load basically mirroring solar production: https://imgur.com/a/VnNJxlv

I can’t see your images, they are regionally protected - but you can add images to your posts as attachments.

For what it’s worth you definitely have a metering problem, either the CT clamp is not wired up, has been extended too far (over 20 metres), or is disabled in the settings - this video shows how to check that https://youtube.com/shorts/WoOPmAlFTuc ... hYt9gcpLxq

Thanks for the reply!

I've added pictures here that show wiring of the clamp, location of it, plus graphs showing wonky data.

I checked the clamp this morning and it appears to be on the right line and not loose. Maybe faulty?

Not easy to tell whether it’s on the right line, but it should be on the main live feed from your supply meter - i.e. it will be detecting everything flowing in and out of the house.

Those connectors are notoriously bad at jointing the cable so that’s a good place to start - certainly over time they will degrade but as a new install they normally work (they really should be soldered).

The inverter losing it’s CT setting is a common ish problem after a new install and firmware update so definitely start there in settings - if it is enabled (it will say >CT<), then it is likely a wiring fault either in those connectors or where the wires connect to the meter connector underneath the inverter (again a common problem) but you should call your installer back to check that for you.

Ah yep so I can confirm it's connected to the red cable coming in from underneath (next to a black a green yellow one, so assume this is the incoming supply)

I did also check the CT setting previously and confirmed that it is set to CT as it should be

Bugger - was hoping I might be able to do something my self but seems like that isn't the case! Is there any point in just twisting the wires together manually (without the little connector) as a test to see if I get anything? Is it possible/likely the clamp itself is faulty?

aplant wrote: ↑Fri Apr 03, 2026 8:56 am Ah yep so I can confirm it's connected to the red cable coming in from underneath (next to a black a green yellow one, so assume this is the incoming supply)

I did also check the CT setting previously and confirmed that it is set to CT as it should be

Bugger - was hoping I might be able to do something my self but seems like that isn't the case! Is there any point in just twisting the wires together manually (without the little connector) as a test to see if I get anything? Is it possible/likely the clamp itself is faulty?

It’s unlikely to be the clamp itself (but not impossible), yes you can try re-making those connections there’s a reasonable chance it’s there and worth tracing that cable from the CT to where it goes into the bottom of the inverter to see if it has been strained anywhere. After that you’ll need to open the connector on the inverter which may be best left to the installer.