There are many variations and different ways that it can be wired but the most common and most basic variation has the power supply to the switch box and a switched line from there to the light. You should see two black wires each connecting to a different screw on the right side of the switch.

3 Way Switch Wiring Diagrams Mr Electrician
Common wire light switch. In this diagram power enters the fixture box. How to wire a 3 way light switch referring to this diagram above the common terminal goes to the red wire to the lamp in the left switch and the black wire on the right side switch. You should also see a green. The reason is because all of the white wires connect. What is a common wire on a 2 way light switch. Red and blue wires link traveler terminals of both switches.
Two way electrical switches have two types of wires connected to them. This 3 way light switch wiring diagram shows how to do the light switch wiring and the light when the power is coming to the light fixture. These are called terminal screws. Observe the layout of the wires. So if you put a switch on the white wire the power may jump the switch and find a different path to the box through another nearby white wire that you cant see. Because the electrical code as of the 2011 nec update requires a neutral wire in most new switch boxes a 3 wire cable runs between the light and switch.
For those of us using led fluorescent or some other energy efficient bulbs under 20w a neutral is required. Common wires and traveler wires. Yes there are a few read very very very few switches that dont require a neutral but those will limit you to incandescent only. The black hot wire connects to the far right switchs common terminal. Split circuit outlet july 4 2019. The red and black are used for hot and the white neutral wire at the switch box allows for powering a timer remote control or other programmable switch.
Low voltage garden path lights july 4 2019. Digital thermostat circuit july 4 2019. 3 way switch common terminal july 4 2019. Dish hopper 3 wiring diagram july 4. The common wire is the only wire that needs to be attached to a particular screw often the dark one on the 2 way switch. A single pole light switch is a fairly simple circuit.
4 wire harness july 5 2019. The other configuration uses a double pole double throw switch. This is an updated version of the first arrangement. Lights and light switches are among the most common wiring elements in a home. In practice you need to put light switches on the hot black wire rather than the white neutral wire. 1994 ford f150 tail light wiring diagram july 5 2019.
This is only way to have a commonterminal. The most common requirement of any hardwired automated light switch is a neutral wire. 2002 nissan altima bose stereo wiring diagram july 4 2019.