Article 368 of the National Electrical Code (NEC) 2023 covers the requirements for busways, which are used for the distribution of electrical power in large commercial and industrial buildings. Busways are designed to carry high currents over long distances, and are typically used as an alternative to conduit and wire systems.
The article begins by defining a busway as “a prefabricated electrical distribution system consisting of busbars in a protective enclosure.” It goes on to state that busways can be used for both indoor and outdoor applications, and can be rated for various voltage and current levels.
The article then outlines the requirements for the installation of busways. It states that busways must be installed in accordance with their listing and labeling, and must comply with all other applicable NEC requirements. The installation must also be performed by qualified personnel, and must be inspected and tested before being put into service.
One of the key requirements for busway installation is proper support. The article states that busways must be supported at intervals that are appropriate for their weight and length, and that the supports must be designed to prevent damage to the busway and to maintain its structural integrity. Additionally, the supports must be installed in a manner that allows for thermal expansion and contraction of the busway.
The article also covers the requirements for busway enclosures. It states that the enclosure must be designed to provide adequate protection for the busbars, and must be constructed of materials that are suitable for the application. The enclosure must also be able to withstand the mechanical stresses that can occur during installation and operation, and must be properly grounded and bonded.
Another important aspect of busway installation is the connection of equipment to the busbars. The article states that equipment must be connected to the busway in a manner that provides a reliable electrical connection and prevents damage to the busbars. Additionally, the connections must be made in accordance with the manufacturer’s instructions and any applicable NEC requirements.
The article also covers the requirements for busway expansion and modification. It states that any modifications to the busway system must be made in accordance with the manufacturer’s instructions and any applicable NEC requirements. Additionally, any expansion of the busway system must be designed to maintain the structural integrity of the existing system.
Finally, the article covers the requirements for maintenance and repair of busways. It states that busways must be maintained in accordance with the manufacturer’s instructions, and must be inspected and tested on a regular basis to ensure that they are in proper working order. Any repairs or modifications to the busway system must be performed by qualified personnel and must be made in accordance with the manufacturer’s instructions and any applicable NEC requirements.
In conclusion, Article 368 of the NEC 2023 provides important requirements for the installation, operation, and maintenance of busways. Proper installation and maintenance of busways is critical to ensuring the safety and reliability of electrical power distribution systems in large commercial and industrial buildings. By following the requirements outlined in this article, electrical contractors and facility managers can ensure that their busway systems are installed and operated safely and effectively.