An ampacity chart is a chart that describes the gauges of different wires and their capacity for carrying current. Ampacities change depending on the type of wire, such as copper or aluminum, as well as other factors.
Ampacity charts serve as guidelines rather than hard-and-fast rules. The length of the wire, the ambient temperature and the wire's thermal conductivity all play a part in determining ampacity. It is best for professional electricians to install and insulate wires because they are aware of the varying amperages and other qualities of metal wire.
Users can refer to an ampacity chart to determine approximate values or they can rely on an ampacity calculator.