Wire and Cable Buying Guide
Cable and wire make up the primary delivery system for the electricity that runs through homes and buildings. While the terms are occasionally used interchangeably, wire is a single electrical conductor, while cable is a group of wires (or conductors) within an encasement of sheathing. From the fuse box to the building’s electrical outlets, it’s important to choose the right cable and wire to ensure that electricity is safely running through a home or business. Learn the basics about multiple types of wire and cable.
Wire is different than cable, making up a single conductor rather than a series of conductors grouped together. Currently, copper is the most common type of conductor used in home wiring projects due to its affordability and its minimum resistance. Wire is grouped according to gauge number. Gauge numbers range from 0000 to No. 40 with the smaller the gauge number, the thicker the wire. Gauges between 10 and 20 are the most common for household projects.
Larger wires carry a larger amount of current. It’s important to select larger wire when in need of excessive current use, as forcing too much current through a smaller wire can cause the wire to overheat, resulting in a tripped breaker. To prevent electrical shocks, it’s crucial that wire is grounded to create a path of least resistance. Grounding wires can be found with both two and three-conductor cables.
Cables consist of groups of two or more strands of wire or conductors. Generally, each cable has a “hot” line used to carry the current, a “neutral” line used to finish the loop, and a third grounding wire. Cable is classified according to its gauge, size and the number of wires it contains. To determine which type of cable you’re dealing with, look for a series of letters followed by a number, a dash, and a second number. This number and letter combination indicate the cord, wire and insulation.
There are several primary types of cable used in homes and buildings. A two-conductor cable contains one white and one black wire. The white is always neutral and the black is “hot” and must be fused. A three-conductor cable contains both a white and black wire, in addition to a red wire which is also considered “hot”. Other options include a BX cable which is an armored cable and a Romex cable that includes two-to-three wires.
When dealing with any type of wire or cable, it’s vital to follow all recommendations set forth by the manufacturer, especially those for outdoor use. Worn or damaged cables should be replaced to prevent electrical shocks or fires. It’s important to know the length of cord you need, as well as the electrical load it carries. Cords should be kept out of the reach of children and in high-traffic areas where individuals may trip over them. Cords should also never be covered with furniture, carpet or appliances. To ensure a proper connection, a cord should be permanently bonded to a plug without wiring exposed.