Issue with FOX ESS KH10 Inverter CT

[sam2005]

Recently, I installed a Fox KH10 plus EQ4800 L9 with the built-in CT (no separate smart meter Chint ddsu666) and have been continuously having issues with the CT installation. Now, the PV only generates just enough for the house load, there’s no battery charging or feed-in even in a clear day.

Has anyone installed a KH10 without a separate smart meter? I think the issue might be due to using the built-in CT. Any suggestions?

Fox support first confirmed it was working, but the next day they said it’s a CT installation issue; this has happened twice.

[Dave Foster]

Just to clarify, the inverter doesn't have a built in CT clamp, it comes with the CT clamp as default (the meter is optional).

The CT clamp is clamped around the incoming live feed of your home and is supplied with a 10 meter cable to wire it into the meter/ct connector of your KH inverter on pins 7 & 8.

It may be that the cable has been extended or cut and joined, when running more than 10metres you have to use good quality shielded cable but it may still only work below 20 metres, (above this you have to use the Chint DDSU666 which can be cabled long distances).

If the cable is joined using a wago or similar, these connections are often failure points - the cable ideally should be soldered and shielded.

From what you have said your system is behaving exactly as if the CT clamp is not connected, it might be worth double checking in the inverter settings (at the inverter panel) that it is set correctly Setting (enter 4 times for password 0000), Feature, Meter/CT, Set and it should say >CT< if it does click the far right key to exit.
If it doesn't say >CT< make sure that it does say 'CT' by using the arrow keys and set it.

NB - all of that can be done remotely by Fox support, so my guess is that you most likely have a distance or connection problem.

[sam2005]

I appreciate your response.
The length of the wire is less than 10 meters, but it's cut and connected using a connector similar to this:
Can this be the cause?

[Dave Foster]

Yes it's possible, the CT cable is a thin multi core which easily snaps and can also react over time causing the cores to oxidise.

I would definitely start there and remake that connector.

[sam2005]

Alright, thank you! It was installed just two days ago.