Article 362 of the National Electrical Code (NEC) 2023 covers the installation and use of electrical nonmetallic tubing (ENT) systems in electrical applications. ENT is a type of raceway that is commonly used to protect electrical wiring and cables in residential and commercial buildings. This article outlines the requirements and standards for ENT, including the installation, protection, and identification of the tubing.
The purpose of ENT is to provide a safe and secure pathway for electrical wiring and cables, and to protect them from damage caused by environmental factors such as moisture, dust, and other contaminants. ENT is typically made of a flame-retardant plastic material, such as PVC or nylon, and is available in various sizes and lengths.
Installation requirements for ENT are outlined in Section 362.10 of the NEC. The tubing must be securely fastened and supported by approved straps, hangers, or other support devices. ENT must be installed in a manner that allows for easy access to the wiring and cables inside, and must be protected from physical damage that could occur during construction or use of the building.
Protection requirements for ENT are outlined in Section 362.12 of the NEC. The tubing must be installed in locations where it will not be subjected to damage from external sources, such as nails, screws, or other sharp objects. In addition, the tubing must be installed in locations where it will not be exposed to hazardous chemicals or environmental conditions that could cause degradation or failure of the tubing.
Identification requirements for ENT are outlined in Section 362.30 of the NEC. ENT must be identified by color, marking, or other means that indicate its purpose and usage. For example, yellow ENT is commonly used for communication and data cables, while blue ENT is typically used for electrical power cables. In addition, identification markers must be placed at regular intervals along the length of the tubing to indicate the contents of the tubing.
ENT is commonly used in residential and commercial applications where it is necessary to route electrical wiring and cables through walls, ceilings, and floors. This type of raceway is particularly useful in retrofit applications, where it may be difficult or impossible to install traditional metal conduit. ENT is also used in situations where it is necessary to protect wiring and cables from exposure to harsh environmental conditions, such as in outdoor applications.
The use of ENT is subject to certain limitations and restrictions, as outlined in Section 362.30 of the NEC. ENT may not be used in hazardous locations, where it could be exposed to flammable or explosive materials. In addition, ENT may not be used to support luminaires or other fixtures, and may not be used as a grounding conductor.
In conclusion, Article 362 of the NEC 2023 provides the standards and requirements for the installation and use of electrical nonmetallic tubing (ENT) systems. ENT is a versatile and cost-effective raceway solution that is commonly used in residential and commercial applications to protect electrical wiring and cables from damage. The installation, protection, and identification of ENT are critical to ensuring the safety and performance of electrical systems, and must be done in accordance with the requirements set forth in the NEC.