Multiple Arrays on ONE Building 2014 NEC

[shortcircuit2]

Residential property has three (3) separate buildings each with their own service and utility meter fed from same utility transformer.

If we put three (3) PV solar system arrays (<10KW each) on the roof of ONE of the buildings on the property and then back-feed separately through the remote individual utility meters. (All inverters will be located on the building with the arrays.) Lets begin this discussion with the consideration of using transformer-less type string inverters. (2 per array single phase)

1. Do the DC Disconnects of each array need to be grouped with the DC disconnects of the other arrays on the building with the three (3) separate arrays?

2. Does the Rapid Shutdown Function of each separate array need to be grouped?

3. Can the PV source circuit conductors of the separate arrays be run in the same conduit?

PVC conduit would be run underground with the AC inverter output circuit conductors from the building with the arrays to the other 2 remote buildings.

4. Can the inverter output conductors of one system be run in the same conduit as the other system?

 

[jaggedben]

Good stuff...
Here are my opinions. (2014 code in MA, right?)

1) Hard to say, but it would be a good idea. I'm even a little unclear if DC disconnects are required on the building with the arrays, but it would surely be a good idea. Such a requirement is not explicit in 690, but might be contained in some other article.

2) No, but it would be a good idea if you are not using a disconnect within 10ft of the array as your method. If you are using some kind of remote method, you could theoretically have one control for all three arrays, which would probably be the best way of fulfilling the intent of the new requirement. (Just wait, in the next code cycle the rapid shutdown section will include a six handle rule. :roll

3) Yes. But check out 690.31(B), especially (3) and (4).

4) Absolutely. And putting the inverters all on the building with the arrays might simplify some of your other issues.