TIA Proposed for 2023 NEC Regarding Boxes, Conduit Bodies, and Handhole Enclosures

The National Fire Protection Association (NFPA) recently released a proposed Tentative Interim Amendment (TIA) to the 2023 Edition of the National Electrical Code (NEC). The TIA was submitted by Frederic Hartwell, Hartwell Electrical Services, and has a comment closing date of February 10, 2023.

TIA Log No.: 1690   

Reference: 314.29(A)

The TIA proposes revisions to paragraph 314.29(A) of the 2023 NEC. The proposed revision can be read here.

Substantiation: CMP 9 has recently become aware of devices designed to mount in front of the outlet boxes that contain their electrical supply. The outlet boxes are recessed entirely behind the building surfaces, with a cylindrical hole cut into the building surface to match the hole in a mounting plate that attaches to the box. The hole diameters are 36.5 mm (1 7/16 in.), sized to receive the actual devices. The device exteriors consist of nonmetallic barrels that engage mating surfaces manufactured as part of the mounting plates. The devices can be removed through the use of a cylindrical extraction tool that closely envelops the outer margin of the cylindrical device, and that in so doing spreads the interior locking tabs, which in turn enables the extraction of the devices, one at a time, after it is pushed into position.

This means that there is little meaningful access to the box interior after the surface material is applied. As noted, the devices can be removed, but the box interior is only viewable to the minimal extent that it can be seen through the finished hole. The surface treatments supported by the system run from 6 mm (1/4 in.) through 19 mm (3/4 in.) and up to 32 mm (1¼ in.), which results in a significant reduction in visibility into the box, especially relative to required equipment grounding connections to the box and also the mechanism for branch-circuit cable and/or raceway securement to the box itself.     

Emergency Nature: The proposed TIA intends to correct a previously unknown existing hazard.       

View the full proposed TIA for more information.