The colors will vary depending on whether nm cable or conduit was used. In the 2nd diagram below blue wires are used for travelers.
Antique Radio Forums View Topic 3 Way Light Switch Woes
3 way switch no traveler. Here in us wire color isnt consistent. 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. A 3 way lighting circuit consists of 2 light switches controlling a single load ie. Image from popular mechanics october 1971. At joshslade needs to determine which 3 way setup he has so we can help him reconfigure the wiring if possible to make this work. Three way switches have three terminals with the one that is not for the two travelers being called the common.
In this setup the load is switched between h n on h h off n h on and n n off. 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. If it was wired with knob and tube originally its possible that the 3 way switch was old enough to be wired as carter 3 way. There is no standard for wire colors on 3 way switch travelers. The switching was designed for a a watchman that had to punch a time clock that he carried with him. There are two clear giveaways that identify a switch as being a three way type.
Thats why i suggested looking at the faq thread. With nm cable the wire colors for travelers will be black and red using 3 wire cable. At the hot end the incoming hot wire is connected to the common terminal. Since the 3 ways have the load on the common terminal the travelers can both test hot. The master switch requires a line 110vac with neutral and ground and load. If one of the black hot wires does have power then that is the wire for the always on plug.
In any 3 way there is a master and slave switch. With conduit the wire colors for travelers could be any color. There are three screw terminals on the body of the switch in addition to the green grounding. There are no onoff markings on the switch toggle. In a situation where a 14 3 romex is the only wire in a switch box the white is either a traveler or load. Such markings are not needed with this type of switch as they are.
The wt00z is great for use in dual switch 3 way applications creating a virtual 3 way switch without need for a traveler wire fitting into any standard single gang electrical junction box. The hot wire leading from the 3 way switch circuit will have no power since all power must travel through the switches. Four way switches have four terminals to connect two traveler pairs to the incoming pair and the outgoing pair. The chicago 3way or tunnel lighting was was allowed by special permission from the inspection dept. Traditionally the slave requires a line and traveler wire to the master.
Gallery of 3 Way Switch No Traveler
