Question 10.5: Twelve 14 AWG copper conductors with Type RHW insulation are......
Twelve 14 AWG copper conductors with Type RHW insulation are to be run in a conduit. The conduit is used in an area that has an ambient temperature of 110° F. What is the maximum ampacity of these conductors?
Find the ampacity of a 14 AWG copper conductor with Type RHW insulation. Type RHW insulation is located in the second column of Table 310.16. A 14 AWG copper conductor has an ampacity of 20 A. Next, use the correction factor for ambient temperature. A correction factor of 0.82 will be used:
20 \mathrm{~A} \times 0.82=16.4 \mathrm{~A}
The correction factor located in Table 310.15(B)(2)(a) must now be used. The table indicates a correction factor of 50% when 10 through 20 conductors are run in a raceway:
16.4 \mathrm{~A} \times 0.50=8.2 \mathrm{~A}
16.4 \mathrm{~A} \times 0.50=8.2 \mathrm{~A}
Each 14 AWG conductor has a maximum current rating of 8.2 A.