National Electrical Code articles and explanations - FREE

Home | Search | About us  

NEC Articles | Quizzes | Questions Answered, $115/hour                Bookmark and Share

nec training

National Electrical Code Articles and Information

NEC Quiz: Article 409 Answers

by Mark Lamendola

Back to Quiz

  1. The ampacity must be at least 125% of the full load current rating of all heating loads plus 125% of the full-load current rating of the highest-rated motor plus the sum of the full-load current ratings of all other connected motors and apparatus based on their duty cycle that may be in operation at the same time [409.20].

  2. Provide overcurrent protection per Article 240, specifically Parts I, II, and IX [409.21(A)].

  3. You must install the overcurrent protection for each incoming supply circuit. Locate it either ahead of the industrial control panel or make it a single main overcurrent protection device within the panel [409.21(B)].

  4. You can't install it where the available short-circuit current exceeds its short-circuit current rating as marked per 409.110 [409.22(A)]. 409.110 is a requirement that manufacturers must meet when building the panel. This Section enumerates seven labeling requirments.
  5. That would be Article 409, Part III.