National Electrical Code Articles and Information

Code Quiz: Article 378

Based on the 2014 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. Since 1996, he has been writing National Electrical Code articles for electrical trade magazines and has an extensive portfolio of hundreds of NEC articles.

After a series of Articles on various raceways, from Article 350 to Article 362, the NEC jumps to Article 366. Then the normal sequence of raceway Articles resumes with Article 376, Metal Wireways." This is followed by, logically enough, Article 378, "Nonmetallic Wireways." And that is the Article this quiz is about.

This wiring method is widely used in a wide range of applications, because it's relatively inexpensive to purchase and it saves a great deal of time during installation versus most other types of wireway or raceway. Metallic wireway is similar; its main advantage is it allows you to create a Faraday shield around the conductors. Nonmetallic wireway has an advantage that metallic can't touch: it doesn't corrode. A disadvantage is you can't use it as a Faraday sheild or as a "grounding" conductor. Nor does it provide a "ground" path. While you "should" run an equipment grounding conductor inside metallic raceway, you MUST run one inside nonmetallic raceway.

This wiring method can be a very good way to go. As with the metallic version, ensure you plan all of your conductor runs out so that you select the proper size before attaching it to the panel wall or wherever it goes.

1. Article 378 is a Chapter 3 article addressing a specific wiring method. Which wiring method does it address, and what are its defining characteristics?
    

2. Name three permitted uses for this wiring method.
    

3. Name the prohibited uses for this wiring method.
    

4. What type hardware is permitted for supporting this wiring method?
    

5. What restriction is there on using couplings and connectors with this wiring method?

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