QA

Question: How To Wire Light Switch

How do you wire up a light switch?

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

Originally Answered: Does it matter which black wire goes where when changing a light switch? If it’s a single pole switch with two terminals, the answer is no. One wire is the power to the switch and the other wire goes to the light.

How is a normal light switch wired?

A single-pole switch has two brass terminal screws on the side that receive the black (“hot”) wires of the circuit. One black wire comes from the power source and the other goes to the light(s). The circuit’s bare ground wire—if there is one— is connected to the green grounding screw on the switch.

What happens if you wire a light switch wrong?

What can happen when you wire a smart light switch wrong? The switch may not work. If you do not connect the switch to the neutral wire, the switch will not have a power supply. If you damage the wires during installation, you could break the switch, or the wires could come loose.

Why does my light switch have 2 black wires?

You should see two black wires, each connecting to a different screw on the side of the switch. These are called terminal screws. These are ground wires.

What is the common wire on a switch?

The common is for the live wire that supplies the input voltage to the switch. The other terminal is marked as L1 and is the output to the light fixture.

What color wire goes where on a light switch?

The white (neutral) wire connects to the silver screw, or you place it in the back wire hole on the same side of the device as the silver screw. 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.

Which wire is hot when both are black?

The black wire is the “hot” wire, it carries the electricity from the breaker panel into the switch or light source. The white wire is the “neutral” wire, it takes any unused electricity and current and sends it back to the breaker panel.

What does L1 L2 and L3 mean on a light switch?

Again, some makes of switch may have alternative markings such as L1 L2 and L3. This type of switch is used where two switches control one light, such as at the top and bottom of a stairway. It can also be used as a one way switch, by using the COM and L1 terminals only.

How do you know if a light switch is wired wrong?

Inside an outlet’s electrical box, the black (hot) wire should be connected to the brass-colored terminal on the outlet. The white (neutral) wire should be connected to the silver-colored terminal. If these connections are backward, the polarity is wrong.

Why does my light switch have two red wires?

When a light is controlled from two locations, you need a switch called a 3-way. A basic 3-way switch has a black wire or connector, called a common, and two traveler wires, usually black, red or blue. The two travelers may be the same color or different colors, but the switch itself will usually be marked.

How do you wire a switch with two black wires?

Connect the top screw to the wire that feeds to the light. Connect the bottom screw to the hot wire. When you turn the power back on, and if you want to swap the direction of the switch (as in press down to turn off, or turn on), turn off the power and switch the two black wires.

Which wire is hot when both are same color?

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.

Why does my light switch have 3 wires?

A 3-way switch makes it easy to turn on a light fixture from two separate locations in the home. Wiring one is slightly different from wiring a single-pole switch. In a standard, single-pole switch, one light switch controls one light fixture—on/off.

What happens if 3-way switch is wired wrong?

Finding the common wire: When wiring a 3-way light switch, you’ll need to find the common wire and connect it to the common screw. If you don’t correctly connect this wire, then your lights won’t work from more than one switch. Since improper wiring is one of the main causes of home fires, this is a serious problem.

Is common white or black wire?

Red, Black, and White are the colors of switch wiring for three-ways. Red and Black are connected to the switches if the White is used for neutral. The White is often referred to as Common, but the colored wires are also used as hot wires.