Codes & Standards

 

Essential to the work of the electrical contractor is knowledge of the National Electrical Code, the National Electrical Installation Standards and additional standards and codes administered by the National Fire Protection Association, the Occupational Safety and Health Administration and others. Here is a list of all our articles on codes and standards listed chronologically by issue date. 

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to codefaqs@gmail.com. Answers are based on the 2014 NEC.
 Previous use of gray conductors


Article 310 in the National Electrical Code (NEC) covers general requirements for conductors and their type designations, insulations, markings, mechanical strengths, ampacity ratings and uses.

A recent change in the 2014 National Electrical Code (NEC) creates a new method for determining the size of service and feeder conductors for 120/240-volt (V), single-phase services for one-family, individual units of two-family dwellings, and individual units for multifamily dwellings.

The 2014 National Electrical Code (NEC) has new requirements for field-applied hazard warning markings, signs and labels. Throughout the NEC, rules that required signs, labels and other markings also required a specific signal word be included in the sign, label or marking.

More on Codes & Standards

 
Group Classifications of Gases or Vapors in a Hazardous (Classified) Location
by Staff |

It is possible to ignite combustible gases or vapors either directly from an arc or spark at the electrical equipment or from the heat generated by the electrical equipment, so extraordinary care must be taken when installing electrical equipment in these areas.

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Making Sense of the Tap Rules
by Staff |

Last month we discussedSection 240-21 tap rules, and the effectiveness of the overcurrent protection for the tapped conductors. Sec. 240-21(b)(4) Taps Over 25 ft.

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Article 210 - Branch Circuits
by Staff |

210-7(d) Replacements

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Article 370 - Pull and Junction Boxes
by Staff |

Sizing requirements for boxes and conduit bodies used as pull or junction boxes are stipulated in Section 370-28. While the boxes within the scope of 370-16 are calculated from the sizes and numbers of conductors, boxes in 370-28 are calculated from the sizes and numbers of conduits (raceways).

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Overcurrent Protection, Access to Working Space, Snap Switches, and More
by Staff |

CODE CITATIONS Article 110—Requirements for Electrical Installations Article 240—Overcurrent Protection Article 250—Grounding Article 380—Switches Article 384—Switchboards and Panelboards Article 450—Transformers and Transformer Vaults

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Low-voltage Lighting - Listed Systems or Individual Field-assembled Components?
by Staff |

Does the National Electrical Code (NEC) require all lighting installations operating at 30 volts or less to be Listed systems? Can individual low-voltage lighting components, such as a power supply, fixtures, and conductors be assembled in the field without being part of a Listed system?

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How Effective Is Overcurrent Protection in the Tap Rules?
by Staff |

The location in the circuit of the overcurrent protection permitted in the tap rules of Sec. 240-21 raises some questions regarding the effectiveness of the overcurrent protection.

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