FoxESS Community - Owners & Installers Forum

Hi,

I'm on Intelligent octopus go and have home assistant set up to control charging of my EP11 through the KH8.

The force charge rate is set at 5kw and my zappi charger is 7kw. So, when the EV starts charging at the same time as the battery is charging I would expect to see 12kw (plus minimal background load) being drawn from the grid. However, what I see in the home assistant is data is that the battery is happily charging at 5kw until the EV starts charging. When that kicks in I can see it drawing 7kw as expected, but the battery force charge then slows to 2kw. Because it's IOG the EV does randomly stop charging during the night and as soon as that happens the battery force charge rate jumps back up to 5kw.

Does anyone know why this is happening? Is something not configured properly on the KH8? Or is there some sort of wiring issue.

Hey,

It's likely your grid import current limit being set to low. Tell your installer the issue and they should be able to spot and increase the grid import current limit setting to match your main DNO fuse.

Thanks for the reply.

Because I can't help messing with stuff myself, I found the relevant setting in Setting -> On-Grid -> Power Limit. There are two settings, Import Limit Power and Import Limit Current. The Import Limit Power was set to 13kw but the Import Limit Current was set to 38A, which is approx. 9120w. So, that explains why I was seeing the battery force charge throttling back.

So, I pushed the Grid Import Current setting up to 60A (14400w). My main fuse is 100A, but I figured that 60A should cover most/all scenarios. Next time I charged the car and battery at the same time I could see a total draw of 12kw, so the problem is now fixed. Thank you for your help, but I have some questions:

1) The inverter can't control the total grid import of appliances such as the car charger, hob, kettle, etc, so why does it have this setting? I assume it's there just so the inverter force charging the battery isn't the reason the total grid import exceeds the main fuse and causes it to blow.
2) Why does it have power and current limit settings that can be set independently? Based on my experience I'm assuming it limits to the lower of the two settings depending on circumstances at the time. If that's the case then the power limit currently set to 13kw will kick in before the 60A current limit.
3) As I have a 100A main fuse do you think it would make sense to up the power limit to ~19kw and the current limit to 80A so I don't run in to any issues in the future?