By Susan Feldman on January 31 2018 15:26:21
In a typical electrical code, some colour-coding of wires is mandatory. Many local rules and exceptions exist per country, state or region. Older installations vary in colour codes, and colours may fade with insulation exposure to heat, light and ageing.
Use wiring diagrams to assist in building or manufacturing the circuit or electronic device. They are also useful for making repairs. DIY enthusiasts use wiring diagrams but they are also common in home building and auto repair.
The environment of the installed wires determine how much current a cable is permitted to carry. Because multiple conductors bundled in a cable cannot dissipate heat as easily as single insulated conductors, those circuits are always rated at a lower "ampacity". Tables in electrical safety codes give the maximum allowable current based on size of conductor, voltage potential, insulation type and thickness, and the temperature rating of the cable itself. The allowable current will also be different for wet or dry locations, for hot (attic) or cool (underground) locations. In a run of cable through several areas, the part with the lowest rating becomes the rating of the overall run.
Most of wiring diagram software has a unique feature for electrical cabling: the wiring diagram or single line diagram, allowing a simplified representation of an electrical cabling installation in pre-study phase.