FoxESS Community - Owners & Installers Forum

I’m discussing the practicalities of the AC grid connection installation with my Electrician for a KH10.5 Hybrid Inverter. We’d like to use 3 core 16mm cable – as per the Inverter guidance for such an inverter rating, however the cable options are quite limited at this size and boil down to either NYY-J (solid core) or the more installer friendly H07RN-F flexible cable.

The problem though is that NYY-J is very difficult to dress from the surrounding containment to the underside of the Inverter and really doesn’t seem appropriate for a plug type installation.

H07 cable on the other hand is ideal and much easier to work with however, whilst the outer diameter of the 16mm H07 cable (23mm) will just squeeze into the supplied grid plug housing the actual fixing inside uses a grub screw fixing for each terminal. Given the fine strands used for each core of the H07 cable a ferrule should be used to maintain good electrical contact with such a screw fixing. If the fixing uses a clamp then a ferrule is optional. The problem is that the plug connector fixing hole is too small for a 16mm fine stranded cable with ferrule fixed.

The immediate workaround suggestion is that the smaller diameter 10mm H07 cable is used instead and given the short cable distance from the supplying AC isolator (<2m), this should be OK.

Have I missed something? What are other installers using in such a situation.

What do Fox recommend is used.

Seems crazy that such a plug would be designed and supplied to not match the real world cable types in use.

Thanks in advance for any guidance.

If you don’t use the EPS you can drop it to 10mm without risk, it’s only when you have the EPS wired and running in pass through mode that the inverter current can get as high as 78A.
Even then it is only when the inverter is charging it’s battery at maximum power whilst you are taking full power on the EPS connection will those limits be met.

The batteries you choose will dictate their maximum charging power, and if that is greater than the inverter maximum output then it will be limited by that instead.
What some installers do (given the cable price, sizing restrictions etc..) and they want to use EPS potentially at full power is to set the maximum battery charge current which restricts the maximum power they can charge at and allows a smaller cable to be used in safety.

Thank you for the advice and seems an appropriate solution for my application.

Just seems a shame that for the sake of a slightly bigger plug connector or different internal fixing method, such a compromise wouldn’t be necessary.

I do wonder sometimes if product designers and manufactures actually put themselves in the shoes of installers and the realities of how their product is to be used.