Conduit and Cable Protection Explained in the National Electrical Code

The National Electrical Code (NEC), which is also referenced as the NFPA/ANSI 70 standard (which stands for the National Fire Protection Association/American National Standards Institute) were first published in 1897. The NEC provides guidance on the standards for electrical cabling and circuits for local communities. The NEC is amended every 3 years, with the latest changes reflected in the 2008 NFPA/ANSI 70.

Addressing Conductors, Cables and Conduit Properties

Chapter 9 of the NEC handbook addresses conductors, cables and conduit properties. These protections are specific for buildings that are non-residential. Wiring in home construction can be installed into the wall without any additional protection needed. Wiring for offices and other commercial or industrial buildings however have different requirements to ensure their proper installation and protect the building from an electrical fire hazard. The NEC addresses the issue of conduit and cable protection in Chapter 9 and provides standards that are adopted by local communities.

Home Wiring in Accordance to NEC Standards

Wiring for homes can be done straight in the wall without the necessity of additional conduits or cable protection for the wiring. A homes use of electricity is controlled by a circuit board that is found in the basement or behind a circuit panel in the home. When problems arise that may cause the electricity to work improperly, a homeowner can simply shut off the main power switch in the circuit box. This interrupts the flow of electricity throughout the home until a qualified electrician can come in and assess the situation.

Commercial and Industrial Building Wiring per NEC

In the case or a commercial or industrial building, electricity flows throughout the site and across many floors. Because there are so many distinct uses of electricity within a commercial or industrial building, different standards are adopted to protect against any catastrophic occurrence. The NEC addresses this concern by expressing the basic code elements that should be adopted and used by electricians when wiring non-residential buildings. These standards, as adopted, provide the minimum level of protection needed to meet the needs of the commercial and industrial building without creating a fire hazard. 

Wiring Standards for Conduit and Cable Protection

The NEC provides guidance for electrical contractors when installing wires in a cabinet or conduit. This guidance addresses issues such as stress and tension placed on the wiring as well as proper ways to place wiring without causing it to bend or tear. Undue stress placed on wires that are placed in a conduit or cabinet will lead to failure of the electrical system, shorts or a potential fire hazard. These standards pertain more to metal ductwork and cabinetry used to house electrical wires. There is less of a concern when placing wires in a plastic conduit since plastic does not have sharp corners or edges that may cause damage.

You can find the conduit and cable protections explained more fully in the most recent copy of the NEC.