The standards development system for the National Electrical Code is a public, consensus-driven process. The NEC receives thousands of public inputs and comments every cycle. But how can a book be consistent if it has thousands of authors? Under the best of circumstances, that is a significant challenge.
After receiving public inputs with recommendations, the Code-making panels get to work writing updates and making revisions to the NEC . The NFPA editorial staff reviews the work of the technical committees and the Code-making panels, flagging them for the technical staff. In the case of the NEC , the technical staff brings editorial issues to the attention of the NEC Correlating Committee, which flags them for the Code-making panels.
All of this work is guided by the NEC Style Manual, which provides a road map for how the Code is constructed. Its purpose is to advise members of the Code -making panels on the required editorial style and arrangement of the NEC . It is intended to be used as a practical working tool to assist in making the NEC as clear, usable and unambiguous as possible. Policing the assembly of the Code is not a glamorous part of the process.
It is vitally important that the text be as explicit as possible, and maximum consistency be achieved in the language in the text. The Correlating Committee needs to review everything by all of the panels to make sure that it all hangs together. Making everything consistent is a challenge, since the panels do not meet with each other, and there can be differences in how issues are dealt with.
Public input is a vital part of the Code-making process, but it presents challenges when trying to keep the Code concise, understandable and consistent. Misconceptions that find their way into the public narrative can be difficult to keep from drifting into the NEC .
For example, the electrical industry is rife with trade terminology. Some of it is universal, and some is regional or local. Some common terms are registered trademarks. The average EC may use these terms every day, but they cause problems when trying to create a clear and concise Code document.
Someone once asked me why we don’t use the terms Romex, BX or Twist-Lok in the NEC , which are universally understood and might add clarity. The problem is that they are all registered trademarks. Using them would either require those particular products, or prohibit their use while not imposing the same requirements on a competing product that passes the same tests. At times, trademark holders have even asked that their trademarked term be removed.
Another issue is the misunderstandings about the common distribution voltages. The average consumer refers to 110-volt (V) circuits and 220V circuits. I have even seen some receptacles and utilization equipment marked 110V.
Possibly contributing to the problem is the ratings for equipment don’t always match the nominal voltage ratings. For example, the receptacles for those same circuits are rated 125V or 250V. Motors for those same circuits are often rated 115V or 230V. The ratings of the motors and the receptacles are codified in product standards. However, Section 220.5(A) codifies the ratings of branch circuits as having nominal voltages of 120V, 240V, 120V/240V. Nominal voltage is defined in Article 100 as “A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts).”
ANSI C84.1 is the standard for voltage classes. Each nominal voltage has a stated range that reflects the reality of installation conditions and the fact that circuit voltage isn’t an exact value due to circuit loads and voltage drop. The commonly used numbers are at the low end of the ranges. The actions taken by the Code-making panels and the Correlating Committee need to normalize the voltage ratings to the nominal rating for circuit/system voltages throughout the Code. They also need to use the voltage ratings of equipment that are consistent with the ratings of equipment from the product standards.
Location and application of outlets is another consistency issue. Sections 210.52, 210.65 and 210.70 all address the location of outlets. An outlet is defined in Article 100 as “A point on the wiring system at which current is taken to supply utilization equipment.”
Consumers and electricians often think only of receptacle outlets whenever they hear the term outlet. Section 210.52 and 210.65 provide requirements for the location of receptacle outlets. Section 210.70 provides requirements for lighting outlets. The Code also provides requirements for appliance outlets and for smoke alarm outlets. The Code and its training programs need to make it clear which types of outlets that are being referred to. Whenever the Code requires a feature to protect all outlets, it applies to lighting outlets, appliance outlets and receptacle outlets.
For several cycles, the NEC has received public inputs and public comments that specifically ask for equipment to be listed for the purpose. Although it might seem to be warranted, these are often not enacted by a panel, or they are overturned by the Correlating Committee. Why is that?
The reason is that the term “listed for the purpose” often increases confusion, rather than provides clarification. It is vague and it usually raises the question as to what purpose is being identified. The intent is that the Code specifically states the purpose, such as listed for wet locations or for exposure to direct sunlight, etc.
We have had some proposals use the expression “listed by a Nationally Recognized Testing Laboratory (NRTL).” The definition of “listed” stands on its own. It requires the authority having jurisdiction’s approval for suitable listing agencies. The NRTL program is an Occupational Safety and Health Administration program for certifying laboratories that test products used in the workplace. Some states use the NRTL program for lab certification and some do not. It is also important to note that an NRTL laboratory is certified to test products to certain standards. They are not necessarily certified to all standards.
Several years ago, we adopted a new policy regarding units. Metric units appear first, and customary U.S. units appear in parenthesis. We also changed from entirely soft conversions to mostly hard unit conversions. The discussion of soft versus hard conversions is somewhat counterintuitive. A soft conversion is a direct mathematical conversion of the customary unit into the metric unit. The soft conversion is used if the precise unit conversion is essential. A hard conversion is a reasonable approximate conversion. It is used where a high degree of accuracy is not important. The approximation (hard conversion) is the most commonly used unit.
The NEC does not contain any mandatory references to other codes or standards. It only contains informational note references, which are not mandatory requirements of the Code. A constant question is whether or not some of the references are necessary. The NEC should not serve as a standards catalog. If standards are referenced, we have asked include an edition date and that they be regularly updated. The updates haven’t always happened in a timely manner. In some cases, the editorial staff has discovered references to obsolete standards that have been superseded by a totally different standard.
Each article of the Code has a scope statement. Scope statements are written by individual panels, and approved by the Correlating Committee. Since they are the responsibility of the Correlating Committee, some panels resist acting on them. However, their action is essential to the process.
Scopes are statements of fact about what the article covers. During the 2020 cycle, there was a major effort to clean up a number of them. Scopes are not permitted to contain requirements. Recently, several were discovered to contain the unnecessary words “the provisions of.” For example, a scope might read, “The provisions of this article apply to widgets.” The proper simplified wording would be “This article applies to widgets,” which is less wordy and right to the point. Scopes need to be direct, clear statements.
Overall, the requirements should be as concise and to the point as possible. There are a few places in the Code where the requirement consists of multiple paragraphs with many requirements. Often, they would be simplified and made more understandable in list format, but writing a list is actually an art. The opening statement needs to work with each list item, and the individual items in the list need to be consistent. If some list items have titles followed by paragraphs, while other list items as phrases or words, the list is very difficult to follow.
The Code -making groups also try to be as consistent as possible. Once a term is introduced in the Code , we endeavor to use the same term throughout the Code. No one benefits if multiple terms are used for the same thing. For example, “grounding conductor” has been used in the Code , but we have done our best to remove it and replace it with “equipment grounding conductor.”
Exceptions to requirements must be presented in complete sentences so it is clear what is being excluded. Sometimes, it is the entire preceding rule, other times, it is only part of the rule.
The editorial process is one of the mundane, nontechnical responsibilities of the Code-making panels, the Correlating Committee and the NFPA technical staff. It’s a thankless job, but it is essential to the creation of a usable industry tool.