enterprisenx
Member
TABLE 310.15(B)(16) address up to three current carrying conductors in raceway, cable, or directly buried. TABLE B.310.15(B)(2)(1) covers two or three insulated conductors with an overall covering in raceway in free air. Both are based on the same ambient temperature of 30 deg C.
If I had a 3/C #8 AWG cable rated 75 deg THWN, each conductor is insulated with an overall PVC jacket, I would expect to use TABLE 310.15(B)(16) for ampacity determination routing this cable in conduit outside above ground.
While there are many references to the other tables and figures in ANNEX B, I can't find any guidance on using TABLE B.310.15(B)(2)(1) as those ampacities are lower.
Does anyone use TABLE B.310.15(B)(2)(1) for a specific application? This is the only table in this section that applies to free air installation as opposed to underground.
Am I misunderstanding terminology between "three current carrying conductors in a ...cable...being the same as "three insulated conductors with an overall covering"? Are they not both considered multiconductor cable at that point?
Thank you!
If I had a 3/C #8 AWG cable rated 75 deg THWN, each conductor is insulated with an overall PVC jacket, I would expect to use TABLE 310.15(B)(16) for ampacity determination routing this cable in conduit outside above ground.
While there are many references to the other tables and figures in ANNEX B, I can't find any guidance on using TABLE B.310.15(B)(2)(1) as those ampacities are lower.
Does anyone use TABLE B.310.15(B)(2)(1) for a specific application? This is the only table in this section that applies to free air installation as opposed to underground.
Am I misunderstanding terminology between "three current carrying conductors in a ...cable...being the same as "three insulated conductors with an overall covering"? Are they not both considered multiconductor cable at that point?
Thank you!