Home Tags Intermediate Switch Wiring Diagram

Tag: Intermediate Switch Wiring Diagram

Four-way switch wiring diagram depicting the LINE and the LOAD in two separate switch boxes. A two conductor cable with a grounding conductor supply's power from the source to the first three-way switch. From the first switch a three conductor cable goes to the first four-way switch and then to the next four-way switch and ends at the last three-way switch. The white neutral conductor is spliced through each switch box until it is connected to the white LOAD wire in the two conductor cable that goes to the lighting LOAD or ceiling fan. The black LOAD wire terminates on the 3-way switch common screw terminal. Travelers are connected on the 4-ways according to the manufacturers' instructions.

Four-Way Switch Diagrams

Dear Mr. Electrician: I need four-way switch diagrams so I can figure how to wire four-way switches. Answer: You can see my own four-way switch diagrams above and down below.  You can add as many four-way switches as you want as long as you have the LINE and LOAD correctly connected on the 3-way switches at each end. NOTE: Text links below go to applicable products on Amazon.  As an Amazon Associate I earn from qualifying purchases. My four-way switch wiring diagrams are available as stickers from RedBubble.  As a RedBubble affiliate I will earn a commission from each item purchased. FOUR-WAY SWITCH DIAGRAMS The schematic diagram below shows how all four-way switches are wired.  The wiring diagram further down depicts another choice of wiring method. In some countries the four-way is called an intermediate switch.  You would just continue from one 3-way switch box with the 14/3 three conductor cable (Two colored traveler wires, a white neutral, and a bare or green ground wire) in and out of each four-way switch box.  The white wires get spliced through in each switch box. The red and black wires are connected to the four-way switches.  At the other end you connect the other 3-way switch with either the LINE or the LOAD.  See the four-way light switch wiring diagrams above and below. Follow the switch manufacturer’s instructions and wiring diagram as the connections on the switch vary by manufacturer.  Sometimes the switch wiring connection diagram is printed on the inside of the four-way switch packaging box (See example below). Bare or green ground wires are spliced together with a pigtail or two and then connected to the metal switch box with a 10/32 machine screw, and to the green screw on the switch. Due to the proliferation of WiFi smart switches and electronic dimmers the National Electrical Code now requires that a neutral conductor be installed in at least one of the switch boxes.  See Article 404.2(C).  This is easily accomplished by bringing the power feed into the switch box instead of the ceiling light. It is not acceptable, and can be dangerous, to use the equipment grounding conductor as the neutral connection for a smart switch. At one time there were electronic switches and dimmers that were approved to connect the neutral of the switch to the grounding conductor.  That is no longer allowed.  There may be some smart switches for sale that do not require a neutral conductor to operate, but their functions may be limited. You must use electrical boxes for your light switches that are approved for the number of wires and devices that you will be installing.  See article 314 in the National Electrical Code (NFPA 70) to determine what size electrical boxes you should use. Keep in mind that each light switch will count as two wires when calculating your box fill.  In addition any clamps inside of the box will count as one wire.  Cable and conduit connectors that are outside the electrical box with only the locknut and bushing inside do not count as a wire. An...