With the new requirement for the supply side connection that the sum of the ratings of all overcurrent devices connected to power production sources shall not exceed the rating of the service, a question has been raised; can table 310.15(B)(7) be used for the single family residence service entrance conductors that is adding solar? Say a 200amp service adding 40 amps for solar, 4/0 cu ok?
Solar Photovoltaic Point of Connection 705.12
- Thread starter abcclub
- Start date
- Status
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
FWIW the service wires are serving all of the dwelling loads but are not necessarily supplying the entire dwelling load when the PV is contributing. The exact wording of the enabling section in the Code becomes important here.
And we already know that the exception makes no sense in the first place, so do not rely on sensibleness arguments.
Tapatalk!
And we already know that the exception makes no sense in the first place, so do not rely on sensibleness arguments.
Tapatalk!
The service conductors would be supplying the entire dwelling load at night!FWIW the service wires are serving all of the dwelling loads but are not necessarily supplying the entire dwelling load when the PV is contributing. The exact wording of the enabling section in the Code becomes important here.
And we already know that the exception makes no sense in the first place, so do not rely on sensibleness arguments.
Tapatalk!
@abcclub,
40A solar is nowhere close to the service rating of 200A... :blink:
mwm1752
Senior Member
- Location
- Aspen, Colo
- Supply Side. An electric power production source shall be permitted to be connected to the supply side of the service disconnecting means as permit ted in 230.82(6). The sum of the ratings of all overcurrent devices connected to power production sources shall not exceed the rating of the service.
Power Production Equipment. The generating source, and all distribution equipment associated with it, that generates electricity from a source other than a utility supplied service.
If the utility is not a power production source then you should be able to have up to 180A of PV on 4/0 AL.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
In my opinion, if the service conductors qualify for meeting 310.15(B)(6), then that's the rating of them for the purposes of 705.12(A).
In other words, if you have 4/0 cu conductors, in my opinion you can tap them on the line side of the service disconnecting means for up to 250A of solar.
There are a lot of potential caveats to that, of course. Some other part of the service (e.g. meter socket) might be a more limiting factor, or it might not be possible to tap in a code compliant manner.
Finally your AHJ may not agree that they still qualify for 310.15(B)(6) if you tap them to install solar. Good luck on that. I doubt anyone on a code making panel has even thought about that.
In other words, if you have 4/0 cu conductors, in my opinion you can tap them on the line side of the service disconnecting means for up to 250A of solar.
There are a lot of potential caveats to that, of course. Some other part of the service (e.g. meter socket) might be a more limiting factor, or it might not be possible to tap in a code compliant manner.
Finally your AHJ may not agree that they still qualify for 310.15(B)(6) if you tap them to install solar. Good luck on that. I doubt anyone on a code making panel has even thought about that.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Last edited:
mwm1752
Senior Member
- Location
- Aspen, Colo
Figured it was a typo
- Status