formerly Table 310.15(B)(3)(a)
Adjustment Factors for More Than Three Current-Carrying Conductors in a Raceway or Cable
| Number of Conductors | Percent of Conductor Ampacity |
|---|---|
| 4–6 | 80 |
| 7–9 | 70 |
| 10–20 | 50 |
| 21–30 | 45 |
| 31–40 | 40 |
| 41 and above | 35 |
Number of conductors is the total number of conductors in the raceway or cable adjusted in accordance with 310.15(E) and (F).
"Conductor Ampacity" is from Table 310.16 through Table 310.19, as adjusted for ambient temperature if necessary.
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DISCLAIMER: All tables on this site are based on the 2020 National Electric Code. The law under your local jurisdiction may be different than what is presented here. Check your local jurisdiction's laws before attempting to do electrical work.
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