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NEC Quiz: Article 250, Part Nine

Quiz Questions

Code Quiz: Article 250, Part 9

Based on the 2008 NEC

Questions and answers written by Mark Lamendola, who has worked as a master electrician, electrical inspector, and design engineer. Mark is an IEEE Senior Member, and the Code article author for Codebookcity.com. He is a former editor of an electrical magazine were he edited Code articles.

  1. What two conditions must a metal underground water pipe meet, if you use it as a grounding electrode?
     

  2. What's the minimum depth for a ground ring? Choose: 18 inches, 24 inches, 30 inches, 36 inches.
     

  3. What portion of the length of a driven rod must be in contact with the soil?
     

  4. What's the minimum depth for a plate electrode? Choose: 18 inches, 24 inches, 30 inches, 36 inches.
     

  5. What two requirements are auxiliary ground rods exempt from?
     

 

Answers to this quiz are here: Answers to this quiz

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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.

 

 

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