So hopefully with a little better understanding of 705, I have made some design changes to meet the requirements of 705.12. I wrote in a previous thread that I had a 320 meter socket with (2) 200 amp ge disconnects mounted on a strut rack. 3'' conduit runs from this rack 200' to a barn where up to a 15kw solar system will be installed by others. What I propose to do is bring 250 al to a 200 amp fused disconnect with 110 amp fuses installed and feeding out of disconnect with 250 al to a 200 amp main lug panel, where the solar company can install their 80 amp breaker and I can install wiring to the interior of the barn. This would be based on the 2011, if the AHJ required the conductors be rated at 233 amps then 350 al will be pulled to a splice box and polaris taps would allow me to change to 250 cu, largest wire that will terminate in my disconnect lug. Look compliant? To allow for vd phase conductors are increased and egc is increased also, does this same type of vd rule apply to solar installs?
New Design
- Thread starter eds
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jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Looks compliant ... but seems expensive?
If you really only need 110 amps to the barn, why not put the disconnect at the service end of the run, and a main breaker panel at the barn? Then your 300ft run only needs to be rated 158A even if the AHJ decides to enforce the rule that way. (110+80 divided by 120percent). You'd still need 233A wire between the service and the disconnect next to it, but that's much cheaper. You could put a 125A main breaker in a 200A panel at the barn and be fine. I will grant that the upside of the plan you describe is that you could upsize the fuses to 150A and still be okay.
Or, why not just run the original plan by the AHJ and see what they say? (What does the solar company say? Or is the problem that they're still being selected? If they have any experience with the AHJ that could be helpful.)
If you really only need 110 amps to the barn, why not put the disconnect at the service end of the run, and a main breaker panel at the barn? Then your 300ft run only needs to be rated 158A even if the AHJ decides to enforce the rule that way. (110+80 divided by 120percent). You'd still need 233A wire between the service and the disconnect next to it, but that's much cheaper. You could put a 125A main breaker in a 200A panel at the barn and be fine. I will grant that the upside of the plan you describe is that you could upsize the fuses to 150A and still be okay.
Or, why not just run the original plan by the AHJ and see what they say? (What does the solar company say? Or is the problem that they're still being selected? If they have any experience with the AHJ that could be helpful.)
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
How about nixing the disconnect near the meter altogether and using 230.40 ex#3?
Utility wont allow that
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
- Status