Wires are the main conduit for electrical current to travel in homes and commercial buildings. If the wrong size wire is used for an electrical circuit, it can overheat and cause damage or even start a fire. For this reason, it is essential to select the right size wire for each application. One of the ways to determine the correct wire size is by using a wire gauge chart. This chart shows the current capacity and diameter of different sizes of electrical conductors. It also indicates the maximum amount of current that can pass through a particular wire with no damages.
The American Wire Gauge (AWG) system is a logarithmic standardized system for noting the diameters of round, solid, nonferrous, electrically conducting metal wire. It is also the way in which body piercing wires are specified.
As the number in the AWG gauge size chart decreases, the wire becomes thinner and smaller in diameter. It is based on the number of drawing operations needed to produce a given wire size and gauge, with each draw reducing the diameter of the wire.
This system is not the same as the circular mil (cmil) system used in other parts of the world to specify diameters, however, the two are similar and can be converted by knowing the ratio between them. The diameter of a wire is determined by dividing its circumference by the circumference of a circle with a radius of 1 cm. This gives the resulting number in AWG, which is then used to calculate its diameter in mm.
In addition to a wire’s diameter, the number of turns in a wire affects its resistance and allowable current. A more tightly wound wire will have a higher resistance, and thus, a lower current capacity for a given length. Other factors that affect the current capability of a wire include the environment, duration of load, stranded versus solid wire and wire plating.
Choosing the right wire is important for any electrical project, but even more so for large projects like a central air conditioning unit. This is because the wires in such an appliance require a significant amount of power to run. If the wires are too thin, they will not be able to carry the necessary amperage and will overheat or burn. The best way to avoid this is by selecting the proper gauge for each application based on wire length and amperage needs.
To help with this, master electrician Heath Eastman shows host Kevin O’Connor how to use a wire gauge chart and what each wire size is used for. He also discusses the importance of selecting a high quality wire that will carry enough amperage for each specific application. Then, he uses a wire meter to test a wire for proper conductivity. He explains that a low conductivity will indicate a bad connection and that this can be caused by corrosion. He also goes over the difference between parallel and series wiring and what each type is suited for.
