Unusual PV configuration on residence

[earshavewalls]

I have a PV system for a residence that has been submitted. It is a rather large system and a completely unusual (to me) configuration that I am unfamiliar with.

I am uncomfortable with the feeding of a subpanel through the PV disconnect (the disconnect in this case is a 200a panel with multiple feeds from PV and attached to the main service) rather than feeding the subpanel from the main house service panel. This, I believe, has been done in this manner simply because of the capacity of the PV system. I asked why they didn't "line side" the PV system to the Main in accordance with 230.82(6) and was not given a response, rather, they are insisting on this configuration.

I am attaching the single line diagram (without the module arrays shown). I would like some opinions on this system design. I can't seem to accept this design, but maybe some of you out there can either show me the error of my ways or confirm my concerns.

Thanks to all who reply, in advance.

 

[earshavewalls]

Well, anyone out there got any ideas?

 

[jdsmith]

Well, I don't particularly like the design either. 690.64 deals with this, and this system would fall under 690.64(B). IIRC somewhere it is required that if downstream panelboards can backfeed the upstream panelboards that labeling is required, but I can't find it off hand. Also make sure that an uniterrupted (or Burndy crimped) Grounding Electrode Conductor is run from each inverter to the grounding electrode. Some inverters will also require an EGC run to the panel where the phase conductors terminate. I don't know how long the conduit D and C are in the drawing, but a couple taps in panel G and one in the main panel should take care of the GEC.

Also take a look at 690.56(B) - Service disconnecting means and PV disconnecting means must be at the same location or additional labeling is required

 

[earshavewalls]

Thanks for taking a stab at this one jdsmith. It just doesn't "feel" right. They have provided all required signage for the system on another sheet. I still don't feel all warm and fuzzy about it. I believe that I will require an engineer's seal on the system design and accept the engineer's opinion on the design. The designer apparently is not a registrant, although his title is "Engineer" (so is mine, but I'm not a registrant, either) and seems hesitant to obtain a seal for the design.
I guess I'll wait and see if the seal is provided and go from there.

Thank you again for your response.