u/Eagl30n3

I am in the process of upgrading my solar system from an "Island" to having all batteries and inverters in parallel. My current batteries are 15kwh with a maximum continuous load of 200A the cables are 35mm2 with 125A MCB. I have purchased 2 x Victron lynx DC distribution and have a few doubts regarding the optimal cables size.

My understanding is the cable is sized based on the potential load or the maximum supported by the inverter and the NEC 125%. Which I understand as the inverter kW ÷ low battery voltage x efficiency. 6200 ÷ 44 x 0.90 I will get 156.5 x NEC 125% = 195.7 so the next available OCPD is 200A

My biggest confusion is the recommendation is 35mm2 cable with 125A, I get that this is very conservative but not optimal for the inverter capability. I think that the 35mm2 is a bit undersized and a 70mm2 with a 200A OCPD would be more appropriate.

My biggest concern is when the system is under load and the EV is charging the 35mm2 may run hot and the OCPD may trip. Therefore, I'm seeking a bit of clarification and recommendations on what would be the appropriate choice for battery cables and the respective OCPD.

Thanks in advance.

Hi all, I was looking for a DC 600A bus bar for 3 x 15kwh 200A max continuous and came across the Victron M10. I believe that this is what I need but would appreciate some guidance or pointing me in the right direction where I can get some guidance on using this bus bar with 3 x inverter and 3 x 15kwh battery.

Any response would be highly appreciated. My understanding is it will be the batteries that will connect to this but then I am not so certain how and inverter comes into this.

Thanks