construction code books

Home | Search | About us                  Bookmark and Share

 
nec training

National Electrical Code Articles and Information

NEC Quiz: Article 250, Part Seventeen Answers

by Mark Lamendola

Back to Quiz

  1. [250.120(B)]. This is a trick question. A EGC isn't actually a grounding conductor, it's a bonding conductor. The NEC still has issues with correctly applying Article 100 definitions throughout the code. An aluminum EGC is not required to make a ground connection (be connected to earth). In fact, it must be terminated at least 18 inches from earth.
     

  2. [250.122(A)]. Never.
     

  3. [250.122(F)]. You must also run it in parallel. This isn't to gain additional ampacity, but for other reasons.
     

  4. [250.124(A)]. First make, first break for your EGC.
     

  5. [250.122(B)]. It must disconnect all sources of energy.
     

 

 

Don't take your electrical exam twice

Journeyman Electrical Exam Prep | Master Electrician Exam Prep

Learn more about: Harmonics | Motors | Power Quality
 

How the NEC is arranged

  1. The first four Chapters of the NEC apply to all installations.
  2. Article 90 precedes Chapter One, and establishes the authority of the NEC.
  3. Article 80 follows the body of the NEC; it exists as Annex H. It provides the requirements for administration.
  4. Chapters 5, 6, and 7 are the "special" chapters, covering special: occupancies, equipment, and conditions (in that order).
  5. Chapter 8 provides the requirements for communications systems.
  6. Chapter 9 provides tables.
  7. The appendices provide mostly reference information.
  8. Appendix D contains examples that every NEC user should study.

Try your NEC moxy:

  • Do you know the difference between bonding and grounding? Hint: Look in the NEC, Article 100.
  • Does the NEC refer to grounding incorrectly in any of its articles? Yes! So be careful to apply the Article 100 definitions. Don't ground where you should bond.
  • When doing motor load calculations, which Article covers hermetic motors? Answer: While Article 440 covers the application of hermetic motors, it does so only by amending Article 430 because hermetic motors are a special case of motors. For motor load calculations, refer to Article 430.
  • Does the NEC provide a voltage drop requirement? Yes! It does so in a special case, which is Article 648 Sensitive Electronic Equipment. But for general applications, it does not provide a requirement; it merely provides a recommendation in a couple of FPNs.
  • Take our Code Quizzes.

Remember other applicable codes, rules, standards, and references:

  • OSHA's electrical worker safety rules.
  • IEEE standards.
  • NETA standards.
  • NFPA standards.
  • International Codes (if applicable to the installation).
  • State Codes (if the state has them).
  • Local ordinances and permit requirements.
  • Local fire codes.
  • Manufacturer requirements or guidelines.
  • Customer security requirements.
  • Industry standards.
  • Your company's own internal standards, practices, and procedures.
  • Engineering drawing notes.

 

 

Master the NEC | Solve Harmonics | Become a Motor Maintenance Guru

Codebookcity is a subsidiary of Mindconnection, LLC. If you have any questions, comments, or concerns, please write to sales @ mindconnection.com. We do want your business.