PV system with private meter - bonding of neutral

[PetrosA]

I ran into something recently that's somewhat out of my comfort zone. A meter was installed at the inverter (separate structure from main service panel with a 100A subpanel with two hots, a neutral and separated ground returning to the main panel and solid #4 ground from the inverter returning to main grounding electrodes) for the customer to be able to monitor their production. Anyway, I noticed that the neutrals were connected to the bonded lug together with the ground wires - almost like you'd do for a service entrance. As far as I understand code, this is a violation to bond the neutral to the ground here and the neutrals should be bugged (or crimped) and insulated in the meter socket, correct? Ground to the meter socket is provided both from a 6/3 romex (feed in/out) and by conduit from bonded trough under the subpanel and inverter.

I guess what's confusing me is that although PV is like a separately derived system by producing power, it doesn't work on its own if the premises system is off so a ground/neutral bond shouldn't exist here. Any thoughts?

 

[Smart $]

If the PV/inverter system's grounded conductor is solidly connected to the service's grounded conductor, the former is not a separately derived system.

I agree with no N-G bonding at this meter.