I have a 3 wire black white ground power connecting to a switch coming into the box a 4 wire black white red a ground coming from the bathroom ceiling fan into the box i would like to add a 3rd switch for my light above the medicine cabinet how do i connect the power source to the 3rd switch. A three way wall switch is single pole double throw spdt with three connection wires and is typically wired with 123 or 143 cable between the two switches.

3 Way Switch Wiring Diagram Variation 4 Electrical Online
3 wire switch to 2 wire switch. At best replacing a 3 way switch with a 2 way switch that requires a neutral will result in a setup that doesnt work correctly. This is an updated version of the first arrangement. I want to add a switch downstairs. Two way switches are single pole single throw spst with two connection wires and are wired with 122 or 142 cable between the switch and fixture. In order to design a smart switch to retrofit the existing 2 wire installation its either method 1. At worst youll create a short circuit that could damage devices on that circuit electrocute yourself or start a fire.
Thinking out of the box to make mcu work with the 2 wire wiring system. The common on the first dimmer connects to the hot source wire and the common on the second connects to the wire running to the hot terminal on the light. Connecting a two wire light fixture to a three wire power supply cable is not an ordinary occurrence. 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. Is there any way to use a single pole2 wire switch in a 3 way setup. I dont want to rip up the drywall though to put a 3 wire cable in.
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. The source neutral is run through to the light fixture with a splice in each switch box. Three cable wire runs between the switches and 2 wire cable runs from the second dimmer to the light. Putting a rechargeable battery inside the switch to supply the power to the mcu or method 2. The wiring is more complicated than a traditional single pole switch but well explain how to make the connections. I have access to the lights wiring and can add the switch easily there.
Three wire supply cables generally carry red and black hot wires of 110 to 120 volts each with a single white neutral wire. Ive got a light downstairs with the switch upstairs. The 3 wire system is less common than the 2 wire system it includes a neutral at the switch as well as the live and switched live wires. Once youre done youll be able to control a light from two switches. One example of a 3 wire lighting system. Wiring a 3 way light switch is certainly more.
An example of a 3 wire lighting circuit is shown in figure 2. This story features diagrams that show how to wire 3 way switches.