The red wire is usually positive in electrical circuits. Although red usually denotes a positive circuit, there is nothing about the wire itself that makes it positive or negative.
Positive and negative terminals only occur in direct current (DC) circuits. Electricity results from the flow of electrons. In DC circuits, one end is always positive, while the other end is always negative because electrons always flow in the same direction, creating a positive and negative terminal. By contrast, in an alternating current (AC) circuit, the direction of electron flow changes periodically, so no part of the terminal is always positive or negative.Learn More
The black wire is used in all electric circuits and is always the "hot" or live wire. It usually runs from the switch to the electrical load.Full Answer >
The color of wires is dependent on the method of wiring and where one is located. In the United States, a common two-wire ungrounded circuit has a red positive wire and a black negative wire.Full Answer >
Choosing between stranded and solid wire depends on the amount of movement required in each wire. Stranded wire is more flexible than solid wire, which makes it a better choice in situations where a wire needs to move around frequently.Full Answer >
The white wire is the common or neutral wire in a 100-volt service, but the wire can also be gray in color. A white or gray wire can only be connected to another white or gray wire. Knowing the color code is essential for setting up the correct configuration of an electrical system and for safety.Full Answer >