Fill in the blank with the correct answer.
Where more than three current-carrying conductors are installed within a raceway for electrically driven or controlled irrigation machines, the signal and control conductors of the raceway or cable shall ________.

  1. be counted for the purposes of ampacity adjustment (derating) only if such conductors carry continuous loads in excess of 10% of the ampacity of each conductor
  2. be counted for the purposes of ampacity adjustment (derating) regardless of the number of conductors
  3. not be counted for the purposes of ampacity adjustment (derating)
  4. be counted for the purposes of ampacity adjustment (derating) only when the number of current-carrying conductors exceeds 10 conductors
Answer: C

As noted in Section 675.5 of the 2011 NEC, three or more signal and control conductors, installed in raceways of electrically driven or controlled irrigation machines are not required to have ampacity adjustments applied, regardless whether or not such conductors carry continuous loads in excess of 10% of the ampacity of each conductor.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.