Before we move on, there is one last definition to review as we cover the upcoming changes in the 2023 National Electrical Code.
Uninterruptible Power Supply (UPS). This term has been used in the NEC ; NFPA 99, Health Care Facilities Code; NFPA 110, Standard for Emergency and Standby Power Systems; and NFPA 111, Standard on Stored Electrical Energy Emergency and Standby Power Systems. This definition was revised as part of an effort to harmonize the use of terminology and requirements related to emergency and standby power and energy storage among NFPA codes and standards, including the NEC . This is particularly important since these documents are expected to work together, and some extract requirements from other documents. The work was directed by the NEC Correlating Committee. The NEC , NFPA 110, and NFPA 111 all report to the NEC Correlating Committee.
The definition points out that a UPS may provide a more constant voltage and frequency supply to the load. This was previously covered in an informational note.
Changes to articles 90 and 110
We will continue our journey through the 2023 NEC with articles 90 and 110. This may seem out of order. However, I knew that definitions would take a couple of issues to resolve, and I wanted to deal with that before I got into the nitty gritty of the Code requirements.
90.1 Scope. The NEC Style Manual establishes how Code articles are to be put together. It requires every article to begin with a scope that tells the reader what is in the article. The glaring exception has always been Article 90. It had Section 90.2, Scope. However, that section contained the scope of the entire Code , leaving Article 90 without a scope. Beginning with the 2023 edition, 90.1 will be the scope of Article 90, which will read as follows: “This article covers use and application, arrangement, and enforcement of this Code. It also covers the expression of mandatory, permissive, and nonmandatory text, provides guidance on the examination of equipment and on wiring planning, and specified the use and expression of measurement.”
90.2 Use and Application. The previous 90.1, Purpose, contained important information. It has been integrated into 90.2, which has the new title, “Use and Application.” The titles of (C) and (D) have been changed to accommodate the reorganization, but it doesn’t make substantive change.
90.4 Enforcement. This section previously consisted of three unnumbered paragraphs. It is the first example in the Code of changing to a list format to make it easier to locate important information. An informational note was added to this section to add a reference to Informative Annex H. The annex has been in existence for several cycles, yet nothing in the body of the Code pointed out its existence.
90.5(C) Explanatory Material. Explanatory material in the Code is in informational notes. During every cycle, there is a Herculean effort to update all of the informational notes that reference standards. New language recognizes that if there is no edition date reference, the latest edition can be used. However, as the next sentence points out, the references in informational notes are informational and are not enforceable requirements.
110.3(A) Examination. A new list item 8 has been added that requires the evaluation of the vulnerability of network-connected life safety equipment to cyber threats. It also includes references to a series of standards from the International Electrotechnical Commission and a series of UL standards that cover cybersecurity evaluations. It also references UL 5500, which covers remote software updates.
110.3(B) Installation and Use. This is one of the most cited sections in the Code . It requires compliance with the installation and use instructions included in listing, labeling or identification. An informational note has been added to point out that installation instructions can be printed material, QR codes or material available online. QR codes are used frequently as a simple way to provide quick access to information. Also, the manufacturer can easily update the material.
110.8 Wiring Methods. This was a simple clarification. The language in this section seemed to imply that the Code ’s wiring method requirements apply only to buildings or occupancies. This revision clarifies that it applies to premises wiring systems.
110.12 Mechanical Execution of Work. The terms “neat and workmanlike” have been replaced with “professional and skillful.”
110.14(A) Terminals. This section had required that terminal parts be “thoroughly good.” This vague language has been revised to require that terminal parts be “mechanically secure.”
110.16(B) Service Equipment and Feeder Supplied Equipment. This section was expanded to require arc flash warning labels on feeder supplied equipment. In addition, the requirement had applied to equipment rated 1,200A or more. It now applies to equipment rated 1,000A or more.
110.3(B) Installation and Use is one of the most cited sections in the Code . It requires compliance with the installation and use instructions included in listing, labeling or identification.
110.17 Servicing and Maintenance of Equipment. This is a new section that requires service and preventive maintenance of equipment be performed by qualified persons who are trained in servicing and maintenance of equipment.
110.20 Reconditioned Equipment. This is a new section that covers requirements for reconditioned equipment that must be listed and for equipment that is not required to be reconditioned. It also covers equipment that is permitted to be approved by the AHJ.
110.21(A) Reconditioned Equipment. This subsection covers the marking requirements for reconditioned equipment. The original nameplate can remain. However, the original listing mark must be removed or made illegible.
110.22(A) General. The title of this section is Identification of Disconnecting Means. (A) now requires a disconnecting means to be legibly marked to indicate its purpose, unless its purpose is evident. It must also indicate the location of the circuit source that supplies the disconnecting means. This requirement does not apply to one- or two-family dwellings.
110.26 Spaces About Electrical Equipment. The 2020 Code prohibited open equipment doors of large equipment from impeding entry or egress from the workspace. This section established dimensions for large equipment and a rating of 1,200A or more. For this cycle, the requirement was relocated from 110.26(C)(2) to 110.26. This relocation is significant because it now applies to all equipment, regardless of size and rating.
110.26(A)(4) Limited Access. The limited access requirements have been clarified to indicate that the workspace must be unobstructed to the floor by fixed cabinets, walls or partitions. A horizontal ceiling structural member or access panel is permitted in this space if the location of weight-bearing structural members does not require a side reach of more than 6 inches to work in the enclosure.
110.26(A)(6) Grade, Floor or Working Platform. This new section requires the working spaces specified in (A)(1), (A)(2), (A)(3) and (A)(5) to be kept clear, and the floor, grade or platform in the workspace must be as level and flat as practical.
110.26(E) Dedicated Equipment Space. This section was expanded so that it now requires dedicated equipment space for all service equipment, including the disconnects for one- and two-family dwellings in 230.85.
110.28 Enclosure Types. This section covers requirements for the use of electrical equipment enclosures. The criteria for these enclosures is based on NEMA enclosure standards. The changes were primarily to the informational notes to the table. Some of the changes were editorial.
Informational Note No. 3 was revised to add a reference to 502.10(A)(3), which makes it clear that a dust-tight enclosure with threaded bosses can be used in a Class II, Division 1 location as long as there are no taps, joints or terminal connections in the enclosure.
The previous Informational Note No. 4 was deleted as unnecessary and incomplete, noting that the hazardous location references are covered in Informational Note No.3.
A new Informational Note No. 4 was added to address enclosures marked with ”-XH,” which are subject to corrosive environments and indoor hose-down exposure.
Informational Note No. 5 was added to make it clear that some Type 4X enclosures are not intended for outdoor use. Those enclosures are marked “indoor use only.”
Informational Note No. 6 was added to recognize that some Type 4, 4X and 12 enclosures are ventilated. However, they still provide the ingress protection specified in Table 110.28. UL 508A, Industrial Control Panels, contains requirements for evaluating these enclosures.
Informational Note No. 7 was added to reference NEMA 250 for the description of type rating.
110.29 In Sight From (Within Sight From, Within Sight). This term is now defined in Article 100. However, definitions are not permitted to contain requirements. This section establishes the requirements that the equipment be visible and not more than 50 feet distant from the other equipment.
110.31(4) Locks. Section 110.31(A)(4) is titled “Locks,” but also addresses personnel doors. Vault doors that open easily are critical for personnel to escape in the event of an arc flash incident. Previously, the door of a vault was required to open in the direction of egress (exit) from the vault. The door was also required to be equipped with listed panic hardware or listed fire exit hardware. The door is now also required to be capable of opening at least 90 degrees.
Header image by Shutterstock and aShatilov.
About The Author
EARLEY, P.E., is an electrical engineer. Retired from the National Fire Protection Association, he was secretary of the National Electrical Code Committee for 30 years and is president of Alumni Code Consulting Group.