ECN Forum Forums General Topics of the Trade General Discussion Area PV Disconnect and 6 Disconnect Rule

It's not my interpretation, others are doing this as well. The code is fairly clear on the allowance, I think the only issue is what the local AHJ or Fire Marshal has to say about it. The two that we have done were done out of necessity as the cost of upgrading the service equipment would have taken the project beyond the financially feasible point. Usually the appropriate signage and even embellishments on that (detail maps of disconnect locations) will more than satisfy the AHJ and Fire Marshal.

Are you referring to AC modules with integral inverters or small single phase inverters?

In your scenario where are your PV AC disconnects? I know of no utility that would accept a breaker as an AC PV disconnect. The PV disconnects have to have visible blades, either through the use of a window or in the case of smaller disconnects they must be openable when off for visual verification of the circuit being broken.

In the situation you're referring to the utility disconnect (or up to six of them) would be the sole premises disconnect since opening it will shut down the PV inverters. If that wasn't acceptable to the AHJ then a separate PV panel to gather all of the micro-inverter circuits and a panel disconnect would be acceptable I'm sure.

I personally haven't done anything smaller than 50kW with most systems being 500kW to 1MW so micro-anything isn't even a consideration.

Connecting 1MW into a 4000A service with six existing 800A disconnects with no main and only 36" of clear wall space on the other side of the room can be a challenge.

The six throws of the hand rules is per service. IMO, hybrid systems are a combination of multiple services in which typically only one is providing power to a building at one time. I agree its an ahj question however despite a few of my systems with multiple power sources, the main power supply can be disconnected with the throw of only one or two handles.

For example, my last AE system had 7 strings of panels. Although they combine to a single breaker, I would not count that as one of the six throws because my inverter does not run off the panels. They run off from the battery bank and still puts out 120/240. With grid ties, that's is a little different. It's a case by case basis. The inverter dc input breaker or the inverter AC out breaker would count only as one throw to the whole system providing no other system could power the system like a back up generator