3 Basic Electrical Code Questions

Understanding the National electrical Code (NEC) is important if you are engaged in any project involving the installation or replacement of electrical wiring in your home. You will need to know what the National Electrical Code is, what does the code cover and how often is it updated. Each of these questions will be answered in this article.

What is the National Electrical Code?

The National Electrical Code sets the standards for the installation of electrical wiring in the United States. The standard has been in existence since the late 1890s and sets uniform minimum standards for states and local communities to use for the enforcement of wiring codes. The NEC is part of the National Fire Protection Association (NFPA) codes that are set for all aspects of building.

The NEC is also adopted as a standard under the American National Standards Institute (ANSI) and is often cited as the ANSI/NFPA 70 standard. The code serves as the baseline for compliance with local building code standards. The code is widely available to anyone who wants to understand what it is and how the provisions pertain to a project that they are engaged in.

What Does the National Electrical Code Cover?

The code is comprised of 9 sections and 8 annexes (A-H) covering the following areas:

Introduction, purpose, scope and purpose of the NEC

Chapter 1, Definitions and Rules

Chapter 2, Circuits and Circuit Protection

Chapter 3, Wiring Methods and Materials Needed

Chapter 4, General Purpose Equipment

Chapter 5, Electrical Issues Dealing with Special Occupancies

Chapter 6, Special Equipment

Chapter 7, Special Electrical Conditions

Chapter 8, Wiring Communications Systems

Chapter 9, Conductors, Cables and Conduit Properties

In addition to the topics covered in chapters 1 through 9, standards, examples, tables and supporting information is provided in the annexes to the NEC, labeled A through H.

The code book is about 1,000 pages in length and there is a companion 1,100 page handbook that provides additional examples as well as a detail reference to each of the sections of the code.

How Often Is the National Electrical Code Updated?

As stated above, the NEC was first published in 1897, and is updated every 3 years, with the last update to the code competed in 2007 for the 2008 publication. Of the ANSI/NFPA standards that are put out, the NEC is the least frequently updated publication. This gives local builders some relief when relying on the standards of community that are based on a previous un-updated version of the NEC. Communities may take up to 3 years to adopt updates to the NEC.

The 2008 update to the NEC was made more user-friendly by highlighting the changes that were made over the previous NEC publication (2005) and showing what additions have been made to the code. This allows individuals that use the NEC to see what differences or changes have been made over previous editions and incorporate those changes in their electrical wiring installations.