We have two utility interactive inverters feeding step up transformer (208p/13.8kw s)
Your voltage seems to be stepped up to 13.8 K and by placing a tap to supply load two you moved the point of connection to the tap location. Looks like you will need some distribution equipment rated at 13.8 K
I’m not sure I see the advantage to making the tap and moving the point of connection.
I realize you would be saving the cost of one additional trans former to step up the voltage from the distribution (service) equipment at building one to feed the second load from building ones service.
I would think there would have to be some trade offs in cost between 13.8k gear and another transformer to step up the voltage from building one.
Point of Connection.
(D) Utility-Interactive Inverters. The output of a utility-interactive inverter shall be permitted to be connected to the load side of the service disconnecting means of the other source(s) at any distribution equipment on the premises. Where distribution equipment including switchboards and panelboards is fed simultaneously by a primary source(s) of electricity and one or more utility-interactive inverters, and where this distribution equipment is capable of supplying multiple branch circuits or feeders or both, the interconnecting provisions for the utility-interactive inverter(s) shall comply with (D)(1) through (D)(7).
• at any distribution equipment on the premise
• Where distribution equipment including switchboards and panelboards is fed simultaneously by a primary source(s) of electricity and one or more utility-interactive inverters