This article is about NEC Article 110.3, which define main points about about Examination, Identification, Installation, and Use of Equipment.
Examination, Identification, Installation, and Use of Equipment
The National Electrical Code (NEC) sets standards for the safe installation and use of electrical equipment. Section 110.3 provides criteria for evaluating equipment and recognizes that equipment can be deemed suitable through listing or labeling by a third party. However, this section does not itself require the listing or labeling of equipment.
Instead, it requires a thorough evaluation of the equipment by the authority having jurisdiction, which may request evidence of compliance with 110.3(A). This evidence is often in the form of a listing or labeling by a third party.
The NEC also provides specific requirements for wire-bending and connection space in cabinets and cutout boxes (312.6, Table 312.6(A), Table 312.6(B), 312.7, 312.9, and 312.11), as well as in other types of equipment, such as outlet, device, pull, and junction boxes (314.16 and 314.28), switches (404.3 and 404.18), switchboards and panelboards (408.3(F)), and motors and motor controllers (430.10).
NEC Article 110.3 Brief Points
This informational note in the National Electrical Code (NEC) emphasizes the importance of considering any special conditions that may affect the safe use or proper functioning of electrical equipment. These special conditions may include elevated or reduced ambient temperatures, specific environmental limitations, strict power quality requirements, or particular types of overcurrent protective devices.
The necessary information for these special cases may be displayed on the equipment itself, provided in a listing directory as part of the listing information, or included in the documentation that comes with the equipment. This note was revised for the 2011 edition of the NEC.
The National Electrical Code (NEC) requires that manufacturers’ instructions for installation and labeling of equipment be followed, even if the equipment itself is not required to be listed. For example, the NEC allows permanently installed electric baseboard heaters to be equipped with receptacle outlets that meet the requirements for the wall space they are installed in, as specified in 210.52.
However, the installation instructions for these heaters may indicate that they should not be mounted beneath a receptacle. In this case, to meet both the requirements of 210.52(A) and the installation instructions, a receptacle must either be part of the heating unit or be installed in the floor close to the wall, but not above the heating unit.
Section 110.3(B) does not require the listing or labeling of equipment, but it does require a thorough evaluation of the equipment. According to 110.2, equipment must be approved by the authority having jurisdiction (AHJ) in order to be acceptable.
The AHJ may request evidence of compliance with 110.3(A) before issuing approval, and the most common form of acceptable evidence is a listing or labeling by a third party. Some sections of the NEC do require listed or labeled equipment. For example, 250.8 specifies that “listed pressure connectors, pressure connectors listed as grounding and bonding equipment, or other listed means” must be used for connecting grounding and bonding conductors.
Examination-Identification-Installation-and-Use-of-Equipment-NEC-Article-110.3