NEC Article 400 provides the requirements for the use, installation, and construction of flexible cords and flexible cables. This article ensures that these types of wiring are used safely and appropriately in various environments. Here is an overview of NEC Article 400:
400.1 Scope
This section covers the use, installation, and construction specifications for flexible cords and flexible cables, including their connection to equipment and their use in various environments.
400.2 Definitions
Provides definitions for key terms used in the article, such as “flexible cords,” “flexible cables,” and other related terms to ensure clarity and consistency.
400.3 General Requirements
Specifies that flexible cords and cables must be listed for the purpose for which they are used and must be installed in accordance with the manufacturer’s instructions and NEC requirements.
400.4 Types and Markings
Flexible cords and cables must be of a type that is specifically permitted for the application and must be marked with the type designation, voltage rating, and other pertinent information.
400.5 Ampacity
Details the allowable ampacities for flexible cords and cables. It includes tables such as Table 400.5(A)(1) for cords with three or fewer current-carrying conductors and Table 400.5(A)(2) for cords with more than three current-carrying conductors. The tables are used to determine the appropriate conductor size based on the intended load and environmental conditions.
400.6 Splices and Terminations
Flexible cords and cables must be used in continuous lengths without splices or taps unless otherwise specified. If splicing is allowed, it must be done using approved methods and materials to maintain the integrity and safety of the cable.
400.7 Uses Permitted
Lists the specific environments and situations where flexible cords and cables can be used, such as for pendants, wiring of fixtures, portable lamps, portable and mobile signs, and appliances.
400.8 Uses Not Permitted
Lists the situations where flexible cords and cables cannot be used, such as:
- As a substitute for the fixed wiring of a structure.
- Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors.
- Where run through doorways, windows, or similar openings.
- Where attached to building surfaces, except as permitted.
- Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings unless contained within an enclosure listed for plenum use and with low smoke and heat release properties.
400.10 Uses Permitted by Type
Specifies the types of flexible cords and cables permitted for different applications based on their construction and insulation properties.
400.12 Construction Specifications
Details the construction requirements for various types of flexible cords and cables, ensuring they are manufactured to provide the necessary flexibility, durability, and safety for their intended use.
400.15 Pull at Joints and Terminals
Flexible cords and cables must be installed and supported in a way that prevents undue mechanical strain on the conductors, joints, and terminals.
400.22 Equipment Grounding Conductor
Requires flexible cords and cables to include an equipment grounding conductor where needed to provide a continuous path to ground for fault currents.
400.23 Strain Relief
Flexible cords and cables must be provided with strain relief at points of termination to prevent damage to the conductors and maintain a safe installation.
For more detailed information and specific requirements, referring to the NEC Handbook and additional resources provided by the NFPA is highly recommended. This summary includes insights from Electrical License Renewal and The NEC Wiki.