July 2010 Issue #1220

Code

• Branch-Circuit, Feeder and Service Calculations, Part LIII

  Load calculation requirements are in Article 220 of the National Electrical Code (NEC). This article contains provisions for calculating branch-circuit, feeder and service loads. Article 220 does not contain all the provisions that must be considered when calculating branch-circuits, feeders and services. Other references found elsewhere in the Code must be considered.

• Cement Dust, Requirements for Transformer Installations and More

  If you have a problem related to the National Electrical Code (NEC), are experiencing difficulty in understanding a Code requirement or are wondering why or if such a requirement exists, ask Charlie, and he will let the Code decide. Questions can be sent to letthecodedecide@earthlink.com.

• How Are They Used?

  This article, second in a series, addresses design letters and code letters and how they are used in motor-circuit design and installation. It highlights the different characteristics of letters and why it is sometimes desirable to choose one over the other.

• Cutting Edge of Technology?

  Electrical construction has always been a dangerous profession, so finding ways to make the work less hazardous is certainly the goal of the National Electrical Code (NEC); Underwriters Laboratories; the Occupational Safety and Health Administration; NFPA 70E, the Standard for Electrical Safety in the Workplace; the National Electrical Manufacturers Association; the National Electrical Contractors Association; and others within the electrical industry.