By Diane Oneil on February 26 2018 14:59:05
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.
US single-phase residential power distribution transformer, showing the two insulated "Line" conductors and the bare "Neutral" conductor (derived from the earthed center-tap of the transformer). The distribution supporting cantenaries are also shown.
The best way to understand wiring diagrams is to look at some examples of wiring diagrams. Click on any of these wiring diagrams.
For example, a home builder will want to confirm the physical location of electrical outlets and light fixtures using a wiring diagram to avoid costly mistakes and building code violations.
wiring diagram schematics
cat 5 wiring diagram
relay wiring diagram