Anyone have experience with arc flash studies on PV systems? The utility interconnection seems to be a possible source of higher incident energy.

Many PV interconnections and equipment have the same challenges as other types of power system when it comes to arc flash. My experience has been that it still usually comes down to the clearing time of the protective devices as well as their location.

Many times the design involves a transformer and the same “blind spot� problem can exist with PV systems as exists on many other systems. Once such case simply required adding an additional separately enclosed protective device closer to the transformer.

The addition of the PV system will have a negligible effect at the utility connection. PV systems do not store energy like the inertia of rotating machinery does. Even if there is energy storage, the inverter typically limits fault current to one or two times its load rating for a cycle or less. [url="http://www.nrel.gov/docs/fy10osti/46698.pdf"]http://www.nrel.gov/docs/fy10osti/46698.pdf[/url].

Good article - thanks.

What I was referring to was the contribution from the utility at the interconnection. You are quite correct, the contribution from the inverter is quite low. If the fault occurs on the load side of the transformer from the utility interconnection, you have many of the same problems as any other system.