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National Electrical Code Articles and Information

National Electrical Code Top Ten Tips: Article 422 -- Appliances

by Mark Lamendola

Based on the 2017 NEC

Please note, we do quote from copyrighted material. While the NFPA does allow such quotes, it does so only for the purposes of education regarding the National Electrical Code. This article is not a substitute for the NEC.

These are the 10 NEC Article 422 items we deem most important, based on the pervasiveness of confusion and the potential costs of same.

  1. An "appliance" has a specific definition, which you will find in Article 100.
     
  2. Some appliances have a protective device rating on them. This is not telling you how much current the appliance draws. It is telling you the maximum breaker size for the circuit that supplies the appliance. You can't exceed this [422.11(A)].
     
  3. If there is no breaker marking on the appliance, a maximum may still apply. Several types of appliances have maximums, as denoted in 422.11(B) through (G).
     
  4. Central heating equipment, per Article 100, is also a type of appliance. Any such equipment other than fixed space heating equipment must be on its own branch circuit. There are a couple of exceptions, but those essentially allow for very closely related equipment. [422.12].
     
  5. When you are calculating total loads, consider the typical residential water heater to be a continuous load [422.13]. That's because the rule applies to storage type water heaters with a capacity of 120 gallons or less.
     
  6. The flexible cords of garbage disposals, dishwashers, trash compactors, cooking units (wall-mounted or counter-mounted), and range hoods have specific requirements [422.16(B)].
     
  7. If you do any work in a room that has a DIY-installed ceiling fan, beware! DIY people are notorious for code violations, and this is one place they are likely to make them. One common problem is improper mounting. The fan must be supported independently of a standard outlet box, or it must be supported by a box identified for the purpose and installed per 314.27(D) [422.18].
     
  8. A less common violation involves the disconnecting means for the garage door opener. The opener is an appliance, and the motor is typically 1/2 hp. But any appliance with a motor more than 1/8 hp cannot use the panel breaker as the disconnecting means [422.31]. That's one reason these are typically designed to be plug and cord powered. Skipping the receptacle and hard-wiring in the opener would violate this rule. Even if the opener is only 1/8 hp, install a local disconnect to avoid the inconvenience of having the disconnect remote from the opener.
     
  9. Switches or circuit breakers used as a disconnecting means must be of the indicating type [422.35].
     
  10. When you install an appliance, ensure its nameplate remains either visible or easily accessible [422.60]. In most cases, this is nothing to worry about because the appliance can easily be slid or rolled from its installed postion to one that provides nameplate access. In some cases, the appliance cannot be easily moved so the nameplate is easily accessible only if you orient the appliance to face a particular way thus exposing the nameplate.

    If you can't orient the appliance so the nameplate is exposed, then you'll need to devise a means of allowing it to be easily moved. For example, the particular dishwasher you're installing has its nameplate on the back and the unit is an undercounter unit. In this case, you will need to ensure the electrical cable, water supply hose, and drain hose are all of sufficient length to roll the dishwasher out far enough for the nameplate to be read. You'll also have to ensure those hoses and that cable are safe when the unit is rolled back in. So use hoses with steel-braided coverings and run each with a single loop that can expand and contract with movement. Use the loop method with the electrical cable, as well. Route these carefully.

  

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.

 

 
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