Two Separate Buildings, 1 Solar PV System, NEC Comliant?

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Solar Jake

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I have a church that would like a solar PV system with battery backup for resilience. They have two separate buildings, each with their own meter and electrical service. I would like to put solar modules on both buildings, but only connect to the service on the first building, which would then also be backed up by batteries. My question: If the second building has a Rapid Shutdown Switch for the PV modules on that building, and then it crosses over to connect to the service on the first building, is there any NEC codes that would disallow this set up?
 
Solar Jake said:
I have a church that would like a solar PV system with battery backup for resilience. They have two separate buildings, each with their own meter and electrical service. I would like to put solar modules on both buildings, but only connect to the service on the first building, which would then also be backed up by batteries. My question: If the second building has a Rapid Shutdown Switch for the PV modules on that building, and then it crosses over to connect to the service on the first building, is there any NEC codes that would disallow this set up?
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It can be done, with a few considerations. What sort of inverters would you be using?
 
I think it's fine. I'd say you need to put diligent placarding at the service for the 2nd building to tell people where the disconnect/rapid shutdown for the PV array is. Not much else at issue in my opinion.
 
jaggedben said:
I think it's fine. I'd say you need to put diligent placarding at the service for the 2nd building to tell people where the disconnect/rapid shutdown for the PV array is. Not much else at issue in my opinion.
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That has been my opinion so far, can't find anything in the NEC that would disallow this.
 
If these are buildings on separate lots then in my experience it will cause a lot of problems because many AHJs don't want to see the utility service on one lot feeding a building on another lot. So be careful of that.
I don't see how your RSD is going to work. I take it that since this is a battery backup system the disconnection of the service is not the RSD initiator. Are you going to install a shutdown button at each building? Will the button shut down the array only on that building or on both?
 
pv_n00b said:
If these are buildings on separate lots then in my experience it will cause a lot of problems because many AHJs don't want to see the utility service on one lot feeding a building on another lot. So be careful of that.
I don't see how your RSD is going to work. I take it that since this is a battery backup system the disconnection of the service is not the RSD initiator. Are you going to install a shutdown button at each building? Will the button shut down the array only on that building or on both?
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I think he is saying that only the first building has battery backup, so since he is using microinverters, all he needs for RSD on the second building is an AC disco. The AC disco on the second building initiates RSD on that building only, while the AC disco on the first building initiates RSD on both buildings.
 
ggunn said:
I think he is saying that only the first building has battery backup, so since he is using microinverters, all he needs for RSD on the second building is an AC disco. The AC disco on the second building initiates RSD on that building only, while the AC disco on the first building initiates RSD on both buildings.
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correct
 
The only thing that comes to mind is you couldn't run the conductors through the attic of the remote building. You can pop through the eave though just have to stay outside of the building.
 
jaggedben said:
I don't see why.
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230.3 One Building or Other Structure Not to Be Supplied Through Another.


Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.

This is what I was basing it on.
 
BradPV said:
The only thing that comes to mind is you couldn't run the conductors through the attic of the remote building. You can pop through the eave though just have to stay outside of the building.
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BradPV said:
230.3 One Building or Other Structure Not to Be Supplied Through Another.


Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.

This is what I was basing it on.
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That would only apply if the PV system on the second building were supply side interconnected and the conductors from/to it were unprotected from the utility feed. Otherwise they are not service conductors.
 
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And even if they were service conductors, if they came into the disconnect at ground level there'd be no prohibition on the conductors between the disco and array pass through an attic.
 
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