Quick Answer: Which Wire Is Line And Which Is Load?

How can you tell if a wire is load or line?

Load Wire – Generally connected to the top half of your switch.

If the wire is coming from the top of the switch box, it is likely your load wire.

Line Wire – Generally connected to the bottom half of your switch.

In some cases, line wires are marked with “line”, “pwr”, or a lightning bolt symbol..

Which wire is hot if both are black?

The United States has strict codes relating to home wiring, including clearly defined colors on the outer casing of the wires. Black means hot, white signifies neutral, and green indicates ground. However, if you need to rewire a light switch or a plug socket, you may occasionally come across two black wires.

Why does light switch have 2 black wires?

The bare or green-wrapped ground wires serve as a backup to divert the power safely away in case of an electrical fault. In most cases, two black wires will be attached to the switch’s two terminal screws. … The ground wires will be connected to each other and attached to the grounding screw on the switch.

How can you tell which wire is hot and which is neutral?

Identify the neutral wire in the fixture by looking at the wires. In most modern fixtures the neutral wire will be white and the hot wire is red or black. In some types of fixtures, both wires will be the same color. In this case, the neutral wire is always identified by some means.

What happens if you switch line and load?

Here’s what happens when somebody wires a GFCI receptacle with the load and line wires reversed: The GFCI will work, in the sense that you can plug in a hair dryer and the hair dryer will blow hot air. … If the load and line wiring gets messed up, a ground fault (radio in the tub) won’t trip the GFCI.

What is a load wire in a light switch?

The load wire connects your light switch to your light fixture. When the switch is “closed”, electricity flows from the light switch to your light fixture, turning on the light. … It is usually attached to a brass terminal on the previous switch. It is sometimes black or red. Also known as a hot, live or switch leg wire.

How do you know which wire is black or line?

Tip #1: An easy way to identify the wires in your wall box is by looking at the color. Tip #2: The Load wire is usually coming from the top of the box. The Line wire is usually coming from the bottom of the box.

What color is the neutral?

whiteUS AC power circuit wiring color codesFunctionlabelColor, commonProtective groundPGbare, green, or green-yellowNeutralNwhiteLine, single phaseLblack or red (2nd hot)Line, 3-phaseL1black2 more rows

Does it matter which wire goes where on a light switch?

The black (hot) wire goes to the brass screw or into the hole in the back of the device on the same side as the brass screw. This wire is sometimes red. The green or bare copper (ground) wire, if the device has one, attaches to the green screw terminal on the switch or to the electrical box.