Labeling for PV System...still a service/sds on the loadside of Serv. Disconnect?

[Mr. Monday]

Hi, all!

My company installs solar (grid tied) in Duluth, MN. My question is for grid-tied solar installs, without battery backup or off-grid capabilities, that are installed on the LOAD side of the service disconnect:

In this case, is the PV System even considered a service? Or a separately derived system?

Basically, the inspectors around here are saying it's one of these two and are making us go crazy with labeling, having us label the PV disconnect as a service (so the main service disconnect would be "Service Disconnect 1 of 2", and the PV disconnect "Service Disconnect 2 of 2"), and then sometimes adding building disconnect labels. It wouldn't be so bad, but we are often having to go back to label according to each inspectors different opinion or fancy.

I can't seem to find a good answer in the NEC or online articles justifying their opinion that a grid-tied solar install, with no battery backup or off-grid capabilities, tied in on the load side of the main service disconnect is considered a "service" or a "separately derived system", and I would very much like to fight this and present a case to the inspector area rep. so that we can stop doing this random "Service 1 of 2" labeling that no one can agree on. One inspector told me it's because it has the "potential" of producing on its own...but it's not designed to or programmed to without other equipment, so I don't think that's a reasonable answer either.

Any thoughts or helpful references would be greatly appreciated!

 

[ggunn]

Hi, all!

My company installs solar (grid tied) in Duluth, MN. My question is for grid-tied solar installs, without battery backup or off-grid capabilities, that are installed on the LOAD side of the service disconnect:

In this case, is the PV System even considered a service? Or a separately derived system?

Basically, the inspectors around here are saying it's one of these two and are making us go crazy with labeling, having us label the PV disconnect as a service (so the main service disconnect would be "Service Disconnect 1 of 2", and the PV disconnect "Service Disconnect 2 of 2"), and then sometimes adding building disconnect labels. It wouldn't be so bad, but we are often having to go back to label according to each inspectors different opinion or fancy.

I can't seem to find a good answer in the NEC or online articles justifying their opinion that a grid-tied solar install, with no battery backup or off-grid capabilities, tied in on the load side of the main service disconnect is considered a "service" or a "separately derived system", and I would very much like to fight this and present a case to the inspector area rep. so that we can stop doing this random "Service 1 of 2" labeling that no one can agree on. One inspector told me it's because it has the "potential" of producing on its own...but it's not designed to or programmed to without other equipment, so I don't think that's a reasonable answer either.

Any thoughts or helpful references would be greatly appreciated!

Load side interconnected PV systems are neither separate services nor separately derived systems.

 

[jaggedben]

What ggunn said.

 

[jaggedben]

And for what it's worth, having battery backup or off-grid capabilities doesn't make it a service either. Nor does it necessarily make it a separately derived system. But it arguably does call for more careful labeling of disconnects.

Perhaps to get these inspectors on the right track, point out the requirements for rapid shutdown (690.12) and its labeling (690.56), and follow those requirements to a 't'. Maybe that will satisfy their fetish for labeling things.