Here are all the basic elements you need to understand about electrical wiring. Wires that are not properly matched to the amperage of the circuits they serve can create a notable risk of short circuit and fire. Cable coloring relates to the size of the wires inside the cable and the cable’s amperage rating. For example, white-sheathed NM cable is used for 15-amp circuits, while yellow NM cable is rated for 20-amp circuits. The coloring on individual conducting wires usually does not indicate a size or rating but rather the standard or preferred use of the wire. For example, black and red wires typically are used for current-carrying or “hot” connections, and white wires usually are grounded “neutral” conductors. Green-insulated wires and bare copper wires are used for grounding wires. While looking at the color of wire or cable will help you narrow down the options at the store, reading and understanding the labels on wiring is the best way to ensure you get the properly rated material for your project.
