Article 392 of the National Electrical Code (NEC) 2023 covers the installation, construction, and maintenance requirements for cable trays used for supporting insulated conductors, cables, and other equipment. A cable tray system is a prefabricated structure consisting of sections and fittings designed to provide a support system for electrical cables and conductors.
The article defines a cable tray system as a unit or assembly of units or sections designed and arranged to form a rigid structure for the support of cables. Cable trays can be made of different materials, including steel, aluminum, and non-metallic materials such as fiberglass and PVC.
Section 392.2 provides the general requirements for cable tray installations. It requires that cable trays must be supported in a manner that ensures that they can withstand the weight of the cables, as well as any environmental factors such as wind or seismic activity. The section also specifies that the installation of cable trays must be done in a manner that provides adequate space for maintenance and repairs.
The article also provides requirements for the construction and materials used in the manufacture of cable trays. Section 392.3 requires that cable trays must be made of materials that are suitable for the installation environment, and must be able to withstand exposure to any environmental factors such as moisture, corrosion, or extreme temperatures. It also specifies that all materials used in the construction of cable trays must comply with the applicable UL standards.
Section 392.4 provides requirements for the installation of cable trays. It requires that cable trays must be installed in a manner that ensures that they are adequately supported and anchored, and that they are grounded in accordance with NEC requirements. The section also requires that cable trays must be installed in a manner that provides adequate space for maintenance and repairs, and that the installation must comply with the manufacturer’s instructions.
The article also provides requirements for the use of cable trays in hazardous locations. Section 392.6 specifies that cable trays must be installed in accordance with the requirements of Article 500 through Article 504, which provide specific requirements for electrical installations in hazardous locations.
Section 392.7 provides requirements for the labeling of cable trays. It requires that cable trays must be labeled to indicate the maximum allowable fill capacity, the manufacturer’s name, and any other relevant information required by the authority having jurisdiction.
Finally, section 392.8 provides requirements for the maintenance of cable tray systems. It requires that cable trays must be inspected regularly to ensure that they are properly installed, supported, and anchored, and that they are not damaged or corroded. Any damaged or corroded components must be repaired or replaced as necessary, and any modifications to the cable tray system must be done in accordance with the manufacturer’s instructions.
In conclusion, Article 392 of the NEC 2023 provides specific requirements for the installation, construction, and maintenance of cable tray systems. The requirements ensure that cable trays are properly installed and maintained, and that they can withstand the weight of the cables and environmental factors such as moisture, corrosion, and extreme temperatures. It is important to follow these requirements to ensure the safety and reliability of electrical installations that utilize cable trays.