Continuing on from last month, here are more of the changes in Chapter 4 in the 2023 National Electrical Code.

406.12 Tamper Resistant Receptacles. The requirements for 15A and 20A, 125V and 250V tamper-resistant (TR) receptacles have been revised, expanded and clarified. Boathouses, mobile homes and manufactured homes, including their attached and detached garages, accessory buildings and common areas now require TR receptacles. The requirements for medical and dental offices and outpatient facilities have been clarified to indicate that TR receptacles must be installed in business offices accessible to the public, and in lobbies, corridors, waiting spaces and places used for patient sleeping.

Requirements for assisted living facilities have been revised and expanded to cover residential care/assisted living facilities, social and substance abuse rehabilitation facilities, convents and group homes. New requirements have been added for TR receptacles in foster care facilities, nursing homes and psychiatric hospitals, and areas of agricultural buildings accessible to the general public and any common areas.

The exception has been revised to clarify which receptacles are exempt from the requirement to be TR. The exempted receptacles are those installed in the space occupied or designated to be occupied by the appliance and the appliance cannot easily be moved. It is permitted for single receptacles that supply one appliance and duplex receptacles that supply two where the receptacles are installed within the space.

408.4 Descriptions Required. The title of this section was changed from “Field Identification Required” to “Descriptions Required” to avoid conflict with the term “identified,” which is a defined term in Article 100. In addition, “field” was removed because it implies that identification is not necessary until the installation stage. This change is intended to require a description of the purpose to be available during the plan review stage. The description label is required to be permanently marked so it does not fade over time. Legible handwritten labels are not prohibited. Although each circuit or circuit breaker in a switchboard or switchgear requires marking, a circuit directory is also required. The directory must be located on the face of, inside of or in an approved location adjacent to the door in the case of a panelboard.

The source of supply for switchboards, switchgear and panelboards supplied by a feeder is required to indicate the physical location of the source of supply. There is no exception for this requirement where the location of the source is readily apparent, because some judgment may be required. This marking is not permitted to be handwritten.

408.9 Replacement Panelboards. New requirements have been added for replacement panelboards. It is important to refer to the definition of panelboard in Article 100:

“A single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet, enclosure, or cutout box placed in or against a wall, partition, or other support; and accessible only from the front.”

The definition of panelboard does not include the enclosure. To clarify this point, a new definition of enclosed panelboard has been added to Article 100:

“The new requirement for replacement panelboards provides requirements for installations involving panelboards listed for the specific enclosure, and requirements where the panelboard is not listed for the specific enclosure. If the panelboard is listed for the enclosure, the replacement is permitted to maintain its previous short circuit current rating. If the panelboard is not listed for the enclosure and its fault current is greater than 10,000A, the completed work must be field labeled. If the available fault current is 10,000A or less, any previously applied listing marks must be removed.”

408.43 Panelboard Orientation. During the 2020 cycle, this section was revised to prohibit the installation of panelboards in the face-up position. For 2023, this section was again revised to prohibit installation of panelboards in the face-down position, because that could create working space concerns.

409.60 Bonding. The title of this section was changed from “Grounding” to “Bonding” and the content was revised to make it clear that industrial control panels must be bonded together. The requirements for grounding and bonding were separated into a list format.

409.70 Surge Protection. A new section has been added to require surge protection for safety circuits for personnel protection.

409.110 Marking. The marking requirements for industrial control panels have been clarified. The voltage, number of phases and full-load current are required to be marked on the exterior of the enclosure for each supply circuit. If the industrial control panel is supplied by multiple sources with disconnecting means for each source, the location of each source exceeding 50V is required to be marked on the exterior. Some markings are required to be on the enclosure’s exterior, while some may be more appropriate on the inside.

410.42 Luminaires with Exposed Conductive Surfaces. For the 2023 Code, this section was rewritten into a main rule that requires exposed conductive surfaces of luminaires to be connected to an equipment grounding conductor (ECG). The second sentence of the main rule was separated into a new exception that covers requirements for surfaces that do not require a connection to an ECG; these surfaces are:

• Separated by a listed system of double insulation
• On small, isolated parts, such as mounting screws and decorative bands on glass separated by at least 1½ inches from the lamp terminals
• On portable luminaires with polarized attachment plugs

410.71 Disconnecting Means—Fluorescent or LED Luminaires. The requirement that was in 410.130(G) for an internal or external disconnecting means for fluorescent luminaires that contain double-ended lamps and ballasts first appeared in the 2005 Code. Newer-technology luminaires using LED drivers are now being installed more often than fluorescents because they are more energy-efficient. However, the shock and electrocution hazards for workers remain the same.

The requirement for the disconnect has been moved from 410.130(G), where it applied only to electric discharge lighting, to a new Section 410.71 in Part VI, where it also applies to LED lighting.

Article 410 Part XVII Special Provisions for Germicidal Irradiation Luminaires. The COVID-19 pandemic increased interest in using ultraviolet light sources for germicidal luminaires. Germicidal radiation has been recognized for use in disinfecting air, water and surfaces for many years. Such luminaires are required to be listed and identified as germicidal equipment. This is an important requirement because exceeding radiation levels could be a health hazard. It is also important that the required radiation level be achieved so the desired level of sanitation is achieved. It is currently not permitted in dwellings, unless listed for dwelling use.

Article 422  Appliances. Several sections in Article 422 were deleted because they were product requirements that are unnecessary for field applications, since Section 422.6 requires that all appliances supplied by 50V or higher be listed.

422.18 Ceiling-Suspended (Paddle) Fans.
The requirement for outlet boxes or listed outlet box systems was revised to require that they be “identified for fan support.” Section 422.18(A)(2) was revised to change the terms “locking support,” “mounting receptacle” and “compatible factory-installed attachment fitting” to the new terms accepted by CMP 18: “weight-supporting ceiling receptacle” and “weight-supporting attachment fitting.”

A new 422.18(B), “Location,” was added to address requirements for paddle fans installed in bathrooms and shower spaces. The metal parts of a paddle fan are not permitted within 3 feet horizontally and 8 feet vertically from the top of the bathtub rim or shower stall threshold. This zone is all-­encompassing and includes the space directly over the tub or shower stall.

424.48 Installation of Cables in Walls. This new section was added to recognize heating cables or panel sets that can be installed in or on wall surfaces.

430.1 Scope, Informational Note Figure. The informational note figure and table were revised to make it a more useful tool in navigating Article 430.

430.6 Conductor Ampacity and Motor Rating Determination. This section is used to determine the ampacity of conductors, the ampere ratings of switches and the ampere rating of branch-circuit short-circuit and ground-fault protection. For general motor applications, values in the tables in Part XIV are used, which are based on the horsepower ratings of motors. Table values are used because motors are sometimes replaced. These tables provide information on motors as large as 500 horsepower. The new 430.6(A)(2)(3) was added to require large motors exceeding the table values to use the nameplate current ratings for conductor sizing.

430.52(C) Rating or Setting. This section was revised to include requirements for premium efficiency motors. These motors have largely replaced energy-efficient motors because they have been mandated for many applications for 1–500 horsepower motors since December 2016.