Overview

The National Electrical Code makes a distinction between voltages of 1000VAC/1500VDC or less, and voltages over 1000VAC/1500VDC. This distinction provides a separation of specific requirements for systems utilizing one vol tage range vs another. In previous editions of the NEC these requirements have been spread throughout various sections and articles, making it more difficult than necessary to find. The NEC 2023 has consolidated all of the requirements for branch circuits, feeders and services over 1000 volts AC, 1500 volts DC, nominal into a single, centralized article – Article 235. This will make finding the specific requirements for this voltage range much more centralized.

Applying the 2023 Code

Prior to the 2023 NEC, medium voltage branch circuits were located in varying sections of The Code, and had no single central location. This made it cumbersome to navigate the requirements for medium voltage installations, and caused unnecessary complexity when searching for the requirements for installations over 1000 volts AC, or 1500 volts DC. The 2023 NEC introduces Article 235, which specifically covers branch circuits, feeders and services over 1000 volts AC, 1500 volts DC, nominal. This new article consists of 5 parts that cover general requirements, branch circuits, feeders, outside branch circuits/feeders, and services. The electrical professional now has a centralized location that covers the requirements for medium voltage branch circuits, feeders, and services. This change comes from Code Making Panel 2 (CMP-2), and should promote much greater usability of the NEC as it applies to medium voltage installations.

What’s New for the 2023 NEC?

2020 NEC

In the 2020 Article 235 did not exist.

2023 NEC

In the 2023 NEC, the scope of the newly added Article 235.1 is as follows (excluding any informational notes):

235.1 Scope.
This article provides the general requirements for branch circuits, feeders, and services over 1000 volts ac or 1500 volts dc, nominal.