Standard wire and conduit size is simply the application of industry standards that help to ensure consistency in the size and type of wiring and encompassing conduits that are used for various electrical tasks. By providing a basis or standard, it is possible to ensure that the proper size of wiring and as well as conduit size is used for any given type of project. Various applications require standard types of conduits and wiring in order to meet government and industry requirements.
Wiring is usually graded in what is known as a gauge. The gauge of the wire refers to not only the thickness of the wire, but also to the amount of current that the wire can adequately carry without beginning to degrade. Specifications are generally made for the type or gauge of wire that can be used with any type of electrical appliance or project. This makes certain gauges of wiring standard for use in lamps, while other standards apply to wiring that is used to set up the electrical systems in a home or public building.
In the same manner, the conduit size may vary, depending on the number and type of wires that will be encased in the conduit. Obviously, thin wire will require a smaller conduit, while thicker wires will need a larger conduit. In order to maintain consistency in the relationship between the conduit and the wiring used in a given type of project, many governments impose minimum standards on the relationship between the sizes of the two.
While wire and conduit size requirements may vary from one country to the next, there is a basic formula employed in most cases that ensures safe wiring within the nation. In the United States, a National Electric Code helps to establish the relationship between wire gauge and conduit size. Essentially, the Code identifies the number of wires that can be safely loaded into a given conduit size. For example, up to six wires with a standard wire gauge of 14 can be safely placed into a half-inch conduit. Higher gauges of wire would require a larger conduit size in order to meet national standards.