Question 18kpv Solar main with Grid back-up

Do you want the inverter to only power critical loads or all the loads in case of the grid goes down?

@eg4eric The inverter will power the entire home.  The system will basically be off grid, but I would like to connect a 125 amp circuit from my grid tied building as a back up to the solar.  The grid would never be backfed, only used to charge batteries or run the system in the event of lack of solar production.

I recommend going with either option 7a or 8a. To ensure that no power is sent back to the grid, you’ll need to enable off-grid mode on the inverter.

As for which wiring configuration is best for your setup, I suggest consulting with a licensed electrician to determine the most suitable and safe option for your installation.

@eg4eric Thank you!

I am using an 18kpv  inverter as an off grid system. PV array of 4 strings of 8 panels and 6 eg4 batteries in rack mount. I am set up to use a 12.5 kw predator gen. which I have not needed so far and the system is powering the whole house and left my shop on grid power. I had thought about using grid power to recharge if needed and someone at EG 4 said to run a separate breaker from my grid live panel and come into the 18kpv at the "Generator in" terminals.  I didn't do that because so far I have plenty of pv/battery power.  Its amazing.  We have had rain and overcast solid for the last 8 days and the battery is recharged  by noon every day from the unseen energy coming through the overcast skies. I am in Northern Minnesota.

@leesfunnyfarm That is awesome, thank you for taking time to share.  That is helpful!