Smart$...The way the code is written, the so called PV Disconnect is not subject to any of the important safety rules that Service Disconnects are cover by.
Question 1... Without Service requirements applied to the PV Disconnect in Mikes diagram, the PV Disconnect would not have to be located (grouped) next the Meter and MDP. There could be a supply side connection in a JB by the Meter (or in the Meter) with Service Entrance Conductors running into the building to the PV Disconnect at the opposite side of the building to a location of the inverter without Overcurrent protection until it lands at the PV Disconnect. This would be allowed now right?
1) See 690.14(C) and 690.14(C)(1).
Question 2... Without Service requirements applied to the PV Disconnect in Mikes Diagram, if the PV system didn't require a Grounded Conductor, one would not need to be installed? (And if the PV system did require a Grounded Conductor...705.95(B) says it only has to be sized to the equipment grounding conductor size.)
2a) Correct.
2b) ...where used
solely for instrumentation, voltage detection, or phase detection... which is to say it carries very little current. However, note it says equal to or larger. Sizing for current and ampacity prevail for conditions other than stated, such as with 120V inverters. This is no different than any other feeder conductor. Granted, a bit different than
normal service conductors on the service side, but when bonding and grounding rules are followed, it is just as safe as you are wanting it to be... you're just not seeing it right now.
Question 3... Without Service requirements applied to the PV Disconnect in Mikes Diagram, a Grounding Electrode Conductor would not be required at the PV Disconnect right?
Correct. A GEC is not required. However, a supply-side bonding jumper is. See 250.96 and 250.102(C)
So now we could have a Supply Side Connection with say 100amp Service Entrance Conductors running through a building in PVC (or any allowed wiring method under 230.43) to a PV Disconnect without overcurrent protection near the point of tap...without a Grounded Conductor or Main Bonding Jumper...and without a large enough grounding path back to the point of supply.
Other than not having a main bonding jumper located in the disconnect, everything else is essentially the same as a Service Disconnect. The only difference is the main bonding jumper is located elsewhere. There is still a large enough grounding path back to the point of supply... both of them.
I'm really trying to view your logic from a safety aspect, but I can't see it. I'm not trying to fight over this either...just like the constructive open dialog on the issue. This is what the forum is for.
I do not take you dialog as wanting to fight about it. Just trying to help you see that it is safe.