AC Inverter Output Wiring

[shortcircuit2]

JB...That is why I interpret it to apply. The building is supplied by a feeder from the solar PV system, so it needs a disconnect as outlined in 225.31 and 225.32...except as modified elsewhere in the code like the exceptions in 690.14(C)(1) or in 694.22(C)(1) for DC conductors inside a building.

Code needs to be rewritten to address your situation.

sc

 

[jaggedben]

JB...That is why I interpret it to apply. The building is supplied by a feeder from the solar PV system

sc

While this is definitely somewhat ambiguous, I do not consider grid-tie-only inverters to be a 'supply', so I do not agree with your interpretation. The inverters cannot operate without the presence of the grid, and OCPD operation is the same as any other AC circuit that is without a parallel generation source. The conductors are either energized from the grid side or they are not energized.

By the same logic, we always connect the grid side to the 'line' side of a solar AC disconnect and the inverter to the 'load' side.

With stand-alone and hybrid systems the interpretation would be different.

 

[ggunn]

By the same logic, we always connect the grid side to the 'line' side of a solar AC disconnect and the inverter to the 'load' side.

Yes we do, and getting this backwards is the single most common mistake made by electrical subcontractors installing PV systems. Our sub made that mistake when installing a 255kW system a few months ago with a 410 foot run of a dual set of 250kcmil conductors. They installed the wire incorrectly on the bottom (load side) of the disco on the roof and cut it too short to reach the top of the switch. Oops.

 

[ggunn]

It seems this has been all one big misunderstanding. It appears the inspectors were arguing from the point of the AC disconnect on the exterior of my garage being the first disconnect. I was arguing from the point of the Enphase connectors being suitable for the first disconnect. The irony in all this is that at no point, in talking with 3 different inspectors, did any one of them understand nor ask about the Enphase connectors being acceptable as disconnects. I am not sure if this is a failure on the part of the inspectors for not fully understanding my system or on my part for not providing more documentation applicable towards the microinverter connectors. Perhaps a bit of both.

If they are willing to consider the opening of a connector as a disconnecting means (do NOT try this in a DC circuit), it kind of sounds to me like a bit of face saving on the part of the inspector, but whatever it takes. I'm glad you were able to reach an understanding with them.