NFPA 70: An Overview of the National Electrical Code for Industrial Business Owners

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If you work with electrical controls, it’s important to be up-to-date on the guidelines and standards that help guide this industry and keep it safe.

Yet, with all of the compliance boards and regulatory requirements to follow, it can be difficult to understand the nuances. Two of the most prominent standard-setting guides are the National Electric Code (NEC) and the National Fire Protection Association (NFPA).

Despite press surrounding these measures, especially NFPA 70, many electricians, engineers, and electrical contractors still aren’t sure what the rules mean or what they entail.

Today, we’re taking a high-level look at the NEC and NFPA. Then, we’ll dive into what NFPA 70 covers and why it’s so important.

Ready to learn more? Let’s get started!

NFPA 70 and the National Electric Code

Let’s get one simple clarification out of the way, first.

The official title of the NFPA 70 is “National Electric Code.” Thus, the terms “NFPA 70” and “NEC” are interchangeable.”

Originating in 1987, standard NFPA 70 details requirements that users must follow when designing and installing electrical systems. It can be difficult to understand in its entirety, as it’s written to speak to high-level electricians and engineers who understand the industry jargon and specifications.

The American National Standards Institute (ANSI) approved NFPA 70 as an American national standard. That’s why you’ll often see it as ANSI/NFPA 70.

Across the United States, many builders reference NFPA 70 when working, adopting the standard into their local building codes. If you live or work in those specified jurisdictions, compliance with the NEC is non-negotiable.

What is NFPA 70?

All 50 states have adopted NFPA 70 in some capacity. It includes nine chapters and 10 informative annexes. You can find the electronic version online.

Note that some jurisdictions may choose to omit or modify some sections of NFPA 70 on their own. Or, they can add their own requirements. These may center on earlier versions of the NEC, or reflect their local accepted practices.

As with most other industry standards, NFPA 70 undergoes a periodic revision process that occurs every three years. This means that new changes occur to it on a regular basis, though its overarching theme and high-level details remain consistent.

While it’s a helpful guide and one that reliable industry professionals follow, understand that while NFPA 70 includes the word “National” in its title, it is not federal law. Nor does it take the place of your equipment’s instruction manual. Rather, it’s meant to serve as a compliance guideline used by trained professionals.

The Recent 2017 Revision

The last revision that the NFPA released was “NFPA 70-2017 – NFPA 70 National Electrical Code, 2017 edition.” To give you an idea of how large-scale an update like this one is, consider that the NEC itself is around 900 pages, and almost every page included a revision! For a simple and visual reference, any changes to the document that happened in the 2017 revision will be gray on your screen or paper.

As this is a national code, revisions are mandatory and unquestionable. Why? The changes made to improve relevancy and reliability often become part of the official practices that builder, installers and maintenance technicians use nationwide.

Rather than safety or maintenance practices, NFPA 70 revolves around installing and maintaining electrical equipment. Its intent is to provide practical safeguarding practices that can protect both people and property from electrical hazards that can arise when users install electrical components.

Minor Change Under the NEC 70

Whether it’s the addition or deletion of a single word or the inclusion of a new set of guidelines, these changes are important to understand, as they can help shape best practices and procedures moving forward. Let’s take a look at a few examples.

First, let’s begin with a minor revision. In the 2017 edition, the NEC updated the definition for cable routing assembly detailed in the section of Chapter 1, Article 100: titled “Definitions.”

Before, the definition had read that a cable routing assembly was a structural system used to support and route the following:

  • Communications wires and cables
  • Data cables associated with IT and communications equipment
  • Optic fiber cables

This new revision tacks on “Class 2, Class 3 and Type PLTC cables” to this list, as well as “Power-limited fire alarm cables” used for riser, plenum, and general applications.

Major Change Under NFPA 70

Next, let’s review a more sweeping change that the NFPA mandated. This one centers on how operators should mark arc-flash hazard warnings.

In 2017, the latest revision added an entire section on that requires users to apply a permanent label to all service equipment rated 1,200 amps or higher. Yet, it didn’t stop there. The new standard also outlines the key data that users should include on each label, including:

  • Nominal system voltage
  • Clearing time of service overcurrent protective devices determined by the available fault current at the service equipment
  • The date that the user applied the label

Revisions Made to Stay Relevant

In addition to basic updates to installation and maintenance procedures, NFPA 70 updates also serve to keep it relevant and ensure that installers stay current in their practices.

Take Article 690 of the code, for example. It focuses on how solar photovoltaic (PV) systems are changing the way users capture and harness solar energy.

Components That NFPA 70 Covers

At its core, NFPA 70 covers the installation and removal of the following electrical components:

  • Electrical conductors, raceways, and equipment
  • Installations that the electric utility uses
  • Signaling and communications conductors, raceways, and equipment
  • Optical fiber cables and raceways for public and private premises, as well as yards, lots, parking lots, carnivals, and substations
  • Conductors and equipment that connect to the electrical supply

NFPA Chapters

Most industry professionals don’t need to sit down and read the entire nine chapters of the NFPA 70 or NEC. Rather, they’ll flip through the documentation to locate the chapter that’s dedicated to their realm of work.

Each chapter includes overviews as well as more detailed articles for a thorough breakdown of every topic. Here’s a look at the chapter-by-chapter breakdown.

  • Chapter 1: General
  • Chapter 2: Wiring and Production
  • Chapter 3: Wiring Methods and Materials
  • Chapter 4: Equipment for General Use
  • Chapter 5: Special Occupancies
  • Chapter 6: Special Equipment
  • Chapter 7: Special Conditions
  • Chapter 8: Communications Systems
  • Chapter 9: Tables
  • Informative Annex A through Informative Annex J

Chapter Details and High-Level Overviews

As shown, the introduction comes first. This chapter sets the stage for the standard and describes its purpose, scope, enforcement and general rules.

Chapters 1 through 4 provide general guidelines for all electrical installations, not taking into account specialized requirements or use cases.

Inside these pages, you’ll find definitions and rules that govern the following:

  • Electrical installations (e.g. voltages, connections, markings, etc.)
  • Circuits and circuit protection
  • Wiring methods and materials (e.g. wiring devices, cables, conductors)
  • General-purpose equipment (e.g. cords, switches, receptacles, heaters)

Some of the most helpful and oft-referenced details located in these chapters include standards around:

  • High-voltage and low-voltage rule classifications
  • Branch circuit requirements
  • Conduit and cable protection practices
  • Actual versus maximum current ratings
  • Temperature ratings for wires and cables

Chapters 5 through 7 serve as supplemental guides that provide extra information to the other chapters. These cover:

  • Special occupancies (e.g. those that pose a high degree risk to multiple persons)
  • Special equipment (e.g. machinery and signs)
  • Special conditions (e.g. alarms and emergency systems)

In addition, users can reference Chapter 8 on its own, but they must take into account the requirements in the other chapters as they do so. This chapter covers extra requirements specific to communications systems only.

Tables and Annexes

Users may not need to ever reference the tables in Chapter 9, though they’re there as backup data, most of which detail individual properties for conductors, cables and conduits.

In a similar vein, the informative annexes aren’t mandatory compliance standards. Rather, they serve to extend the information provided. Some of the most useful annexes include:

  • Details on referenced standards
  • Calculations
  • Real-life examples and applications
  • Additional tables to help users implement the myriad code articles (e.g. answering how many wires fit into a conduit)
  • An ordinance for model adoption

Decoding Article References

As there is an extensive amount of data covered, the NEC breaks down NFPA 70 into articles and points. Users can reference each one by looking at its specific number and letter combinations. These combinations are written as:


For example, if you find Article 804.22(C)(3)(b), you’ll begin in Chapter 8, then go to Section 804, point 22(C)(3)(b).

When internal references appear, some lengthy articles break down even further by referencing “parts” as Roman numerals (e.g. Parts I, II, III).

For those seeking an even more detailed look into the NEC, the organization also publishes an almost 1,500-page guidebook titled “NEC Handbook.” A new handbook comes out at the same time as every new version of the code. The handbook includes the following information:

  • The entire code
  • Supplemental illustrations
  • More detailed explanations
  • Informative cross-references that reference the current and earlier versions of the code

While they’re helpful, especially to those new to the industry, understand that the explanations listed within the handbook are only for reference and are not enforceable.

What is NFPA 70E?

In short, NFPA 70E is another one of the standards that the NFPA publishes. It’s available to review on this website.

It defines the best practices that electrical workers should follow to protect themselves and their workforce from electrical hazards, such as arc flashes. It’s centered more on safety, whereas NFPA 70 focuses on design and installation.

NFPA 70E also sets parameters around how users should inspect, operate and maintain the electrical equipment for optimal performance.

Think the standard applies only to those who make direct contact with electrical equipment in their profession? Think again. If there’s a chance for you to become exposed to any form of electrical hazard during your workday, you’ll need to study NFPA 70E, as well.

In fact, the only entities that aren’t required to follow the NFPA 70E standards include:

  • Vehicles (including aircraft, ships)
  • Railway electrical systems used for the operation of rolling stock or installations
  • Railway electrical systems used specifically for communications and signaling
  • Communications equipment under communications utility control, located outdoors or in designated buildings set apart for such installations
  • Some electrical installations under the exclusive electric utility control

What is NFPA 70B?

While NFPA 70E centers on electrical safety in the workplace, 70B outlines recommended industry practices for electrical equipment maintenance. It was first published in 1968 and you can find an electronic version here.

This standard doesn’t only cover electrical equipment. Rather, it also spans to include electronic equipment as well as communication systems and equipment.

Users can reference NFPA 70B for guidance on systems and equipment installed in the following locations:

  • Industrial plants
  • Institutional buildings
  • Commercial buildings
  • Large, multi-family residential complexes

NFPA 70B spans 35 chapters and covers maintenance intervals and procedures for electrical equipment and systems. In addition, 16 annexes are also included. These provide helpful explanations and recommendations.

Together with NFPA 70 and NFPA 70E, NFPA 70B helps round out the three standards that comprise the “Electrical Installation, Maintenance, and Safety” portion of the overarching NFPA.

Electrical Controls That Comply and Perform

When you’re looking for industrial electrical controls, you know that safety, reliability, and performance are top criteria. Finding parts that comply with industry standards, such as the National Electric Code or NFPA 70, can take the guesswork out of this step.

When you’re looking for top-notch products that comply with code and meet rigorous tests for quality and security, visit our online shop. We’ve filled it with all the tools of the trade, from circuit breakers to terminal blocks.

Take a look around and contact us for support. Codes can be complicated, but the selection process doesn’t have to be.

The content provided is intended solely for general information purposes and is provided with the understanding that the authors and publishers are not herein engaged in rendering engineering or other professional advice or services. The practice of engineering is driven by site-specific circumstances unique to each project. Consequently, any use of this information should be done only in consultation with a qualified and licensed professional who can take into account all relevant factors and desired outcomes. The information was posted with reasonable care and attention. However, it is possible that some information is incomplete, incorrect, or inapplicable to particular circumstances or conditions. We do not accept liability for direct or indirect losses resulting from using, relying or acting upon information in this blog post.