According to 110.14(C) of the 2002 NEC, ... Explanation: First go to Table 310.16. The ampacity of a 250 kcmil THHN conductor from the 90°C column under ordinary conditions (with no adjustments of any ...

The raceway is more than 200 feet long, and it contains three 500 kcmil THHN conductors, one 250 kcmil THHN conductor, and one 3 AWG THHN conductor. What size RNC raceway is ... Step 3: Size the EMT ...