Transfer equipment? Why? The interconnection is just a simple load side connection through a breaker in the MDP like we build every day; it's just that the PV is on one building and the interconnection is on the other. The conductors from the PV do not interact with whatever power the garage has except that they are both tied to the same service.
This is my reading of this.
705.12 Point of Connection.
The output of an interconnected electric power source shall be connected as specified in 705.12(A), (B), (C), or (D).
(A) Supply Side. An electric power production source shall be permitted to be connected to the supply side of the service disconnecting means as permitted in 230.82(6).
I read this as a simple statement an electric power production source shall be permitted to Connect (shake hands with ) the primary source at the supply side of the service disconnecting means as permitted in 230.82(6).
B , C and D says you are permitted to connect at a point elsewhere on the premise from what was stated in A. You are making a load side connection of the inverter output to the primary source
• (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 panel boards is fed simultaneously by a primary source(s) of electricity and one or more utility-interactive inverters
• 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).
Distribution equipment for what the primary source or solar source, define it one or the other but the subject of distribution equipment is the same in all three points above, at least thats how I read it and apply it. I read it that you are connecting to primary source feeder distribution equipment. Build the system than tear out the solar you still can distribute the primary source through the primary source distribution equipment.
I think it is a very gray area to claim you are running two primary source feeders to a building and claim one is a different animal. When the section states it is a load side (of the primary source line side connection point) to any point at any primary source distribution equipment
In my way of thinking it would be correct to run the inverter output circuit to the main building unless you want to define a feeder connection point at the garage a load side connection
keep in mind im still learning i do not think every statement i make will be with out correction