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.
 Phase converters and fire-pump service


Article 450 in the National Electrical Code (NEC) covers requirements for transformers. The scope of Article 450, located in 450.1, states that it covers the installation of all transformers, but there are eight exceptions.

NFPA 70, the National Electrical Code (NEC), is an installation code, while NFPA 70E is the Standard for Electrical Safety in the Workplace. There is an unofficial line of demarcation between the two documents.

An electrical contractor recently requested information about the required emergency disconnects for a motor-fuel-dispensing facility.

More on Codes & Standards

 
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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Article 370 - Pull and Junction Boxes
by Staff |

370-28(a)(2) Angle Pulls

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Motor Control Circuits: To Ground or Not to Ground?
by Staff |

Should motor control circuits be grounded? Here are some guidelines: If a motor control circuit is tapped from the motor circuit and does not leave the controller enclosure (the push buttons are in the cover), then it need not be grounded. [90-7 ¶ 2, 300-1(b), 450-1 Exc.No.2]

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