It is important for anyone working with electrical systems to understand the purpose of both codes, and where they apply.
The Institute of Electrical and Electronics Engineers (IEEE) developed and published the NESC as a source of best practice guidelines for the design and construction of electrical power distribution.
According to the IEEE Standards Association, the NESC “sets the ground rules and guidelines for the practical safeguarding of utility workers and the public during the installation, operation, and maintenance of electric supply, communication lines, and associated equipment”.
The NESC focuses primarily on utility systems like substations, overhead lines, and underground lines.
Who Enforces the NESC?
The NESC is a voluntary standard that is commonly adopted as law at the state level. A majority of US states have adopted the NESC or at least some version of it through state and local jurisdictional authorities.
In most cases, compliance is regulated by governmental authority. Ultimately, how the code is leveraged, what edition is recognized, and who enforces it depends on where you are located in the United States.
The NEC is a part of the National Fire Code series published by the National Fire Protection Association (NFPA). The NEC is also known as NFPA 70 and applies to the installation and maintenance of electrical wiring systems within homes and businesses.
It provides a set of rules for anyone (electricians and in some cases the public), handling electrical systems within those homes and businesses.
Who Enforces the NEC?
The NEC is not a federal law, but a voluntary standard.
Because of this, there are different versions of the code enforced throughout the United States. The authority and enforcement of the NEC depend on how the state or local jurisdiction chooses to adopt and apply it.
The NFPA encourages the adoption of the most recent edition of the NEC (2020), but as of April 2021, the 2020 NEC is only in effect in eleven US states.
Key Differences Between the Two
Understanding the distinctions between the NEC and NESC is key to a safe environment when working with electricity. Although not absolute, two factors can help separate the codes: the type of electrical systems being handled and the role of the people handling those systems.
The systems the two codes work with are quite different. The NESC focuses on large power systems that supply power to homes and businesses. The NEC focuses on the electrical systems within those homes and businesses. In most situations, the NESC applies to equipment and systems utilizing substantially higher voltage than those applicable to the NEC.
The second factor builds off the one mentioned above. While electricians and utility workers both deal with electricity, the environments in which they operate present unique safety requirements. Utility workers typically work with high voltages while electricians usually work with lower voltages.
It is common practice for utility workers to work on live currents to avoid disrupting power distribution. This kind of electrical service work follows the NESC. Electricians often work on “dead” equipment and work with in-premise wiring, applying more to the NEC.
In many situations, the line dividing the two codes and their relevance to an application can be exceptionally vague. One of the main complications is how the codes are interpreted and enforced varies by location.
Given the voluntary nature of both codes, a jurisdiction can take a customized approach to meet their own requirements or adopt both codes as written. Local jurisdictions can adopt the NEC, the NESC, or some combination of the two. This, along with other factors, potentially makes training difficult for those who work in multiple areas or states.
How They Work Together
It is important to note that the NESC and the NEC are not contradictory in nature; they go hand in hand.
Understanding the relationship between the two starts with understanding the term “service point”. A service point is the point of connection between the facilities of the serving utility and the premise’s wiring, like a meter. It defines the point of demarcation between utility responsibility and customer responsibility.
The NESC is generally applicable to the systems and equipment that supplies power to the service point, by utilities. The NEC typically covers the systems and equipment that starts at that same service point and continues into a building.
Service point locations are not the same in every situation and every jurisdiction has its own service requirements.
Being familiar with your location’s adopted codes and interpretations is always a good idea, for both sides of the service point.
The Electromark Difference
Electromark is familiar with both the NEC and NESC. Given the nature of our business, the NESC is the standard we work with the most out of the two, but we do offer standard NEC-compliant products and can design compliant custom products as well.
If you have any more questions or comments, feel free to reach out to our customer service team.
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