Supply Side PV Connections

[DLN]

I would like to get some feedback concerning connecting PV Solar arrays to Main Service Panels that do not have a main disconnect, the 6 handle throw types of services. We do a lot of solar in my region and we've been hearing different opinions concerning 705.12 (A). What we're trying to get clarification on is:

1) Does the disconnecting means of the PV system count as one of the "six" handle throws, since technically, the disconnecting means for a PV system is not a service disconnect, as "service" is defined in Article 100?

2) Should the sum of the amperage ratings of all six disconnects, including the PV disconnecting means, be limited to the amperage rating of the service/bus?

Some folks are saying that, Yes, the PV disconnect is counted as one of the "six" disconnects, or "handle throws" and that it's amp rating needs to be added to the amp rating of the other 5 disconnects, and that sum shall not exceed the rating of the panel.

Other folks are saying that, No, the PV disconnect is NOT counted as one of the "six" disconnects, or "handle throws", and that it does not matter what the sum of the six disconnects are rated at. If the service panel is rated for 200 Amps, then the PV disconnect added to the service could be as large as 200 Amps, for example.

I will try to check back once a day to see what kind of comments have been added. Any published literature from recognized professionals concerning solar connections would be welcomed, as well. Thanks!

 

[ICE]

1) Does the disconnecting means of the PV system count as one of the "six" handle throws

Yes.

2) Should the sum of the amperage ratings of all six disconnects, including the PV disconnecting means, be limited to the amperage rating of the service/bus?

Not until the 2014 NEC is adopted.

If the service panel is rated for 200 Amps, then the PV disconnect added to the service could be as large as 200 Amps, for example.

The code says "bus or conductor" so you also have to pay attention to the service entrance conductor. But yes is the answer. Until the 2014 NEC is adopted that is.

It would take one helluva solar system to hit even 100 amps.

 

[DLN]

Thanks for the input ICE. That's kind of my take, too, but here's where my problem lies. Since it's coming in the 2014 NEC, that tells me that there is a recognized life safety issue with the way the code is now, and relying on the fact that the code does allow it now, doesn't make it any more safe of an install. It's still up in question here if we're going to implement the change now, or continue to let the contractors install it the way the code allows now.