Table 310.16 is for not more than three current carring conductors in Raceway, Cable,or earth. Table 310.17 is for Single insulated conductors in free air space. Ok my question is if I have a 200 amp overhead service drop to a building using 4/0 aluminum Tri-plex do I use table 310.16 ampacity or 310.17 ampacity since it is in free air space??
Conductor Ampacity Question
- Thread starter cwain
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Is this triplex from the utility?
- Location
- Illinois
- Occupation
- retired electrician
You use T310.20. The problem will be finding what column to us as I don't think triplex uses any of the NEC insulation types.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I agree with Don, you might have trouble find a listed triplex for this application.
- Location
- Massachusetts
I agree with the others but want to point out that if you where to use Table 310.20 you would really have to consider voltage drop as using that table to it's limits would substantially increase voltage drop.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
If you have a NEC handbook, read the commentary following 110.14(C).
- Location
- Massachusetts
There are work arounds to the termination temps.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Please share! (Something other than the junction box at each end?).
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