Three wire supply cables generally carry red and black hot wires of 110 to 120 volts each with a single white neutral wire. This wire is sometimes red.
How Do I Change A Single Pole Light Switch All Three Wires
Three wires in light switch. If you dont have a ground wire leave the green screw unconnected. Re wiring 3 way light switch hi guyscould really do with some advice for replacing a 3 way single light switch. The other 3 wire cable originates at the second switch box and will become the switch leg. 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 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch.
An example of a 3 wire lighting circuit is shown in figure 2. This is a typical wiring setup for a 3 way light switch with black white red and ground wires. Wiring a three way switch. In a hallway or large room for example installing three way switches at both ends lets you turn the light fixture on or off from both locations. One 3 wire cable originates at the first switch box and has its white insulated wire as a neutral. One example of a 3 wire lighting system.
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. A three way wall switch is a common type of light switch that makes it possible to control a ceiling light or other electrical fixture from two different locations in a room. In this diagram the incoming hot wire attaches to the first switchs common dark colored terminal. In the light fixtures box there will be two 3 wire cables. 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. 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.
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 lighting could be added to the three wire cable provided that the circuit breaker is no more than 15 amps and the wire size is no greater than 14 gauge. If you have a ground wire connect the ground wire to the green screw. If it doesnt work switch the lower wires. The old switch had four wires going into l1 l2 l3 and l4.