4 Way Switches – Explanation with Wiring Diagram


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If you’re looking to build a home, office space, or are just reading up on electricity, you’re in the right place! In most buildings, in order to be “to code,” there must be a switch to the main light at every room entrance. This is a good reason for you to learn more about four-way switches.

What is a four-way switch? Four-way switches are switches that are used to control lighting. This particular switch is going to control the lighting from three or more locations. Each four-way switch is accompanied by three-way switches on either side of it. They do not have an on/off switch label and can often be tricky to troubleshoot due to their wiring. 

While four-way switches are quite common, there are a few different kinds of switches that may be helpful for your project or knowledge. It is also important to note that voltage plays a factor whenever you are changing out your switches or planning for building. This article will not only walk you through different switches but also differing voltage.

When Would You Use a 4-Way Switch

As open style floor plans become more and more popular, the need for additional light switches also increases. You see, the bigger a space is, the more likely you are to want the convenience of turning on the lights from all entry points.

In smaller, older construction, rooms are compartmentalized and so each room has one natural place for a switch, at the door. Larger rooms, like the living room, might use a 3-way switch to control the lighting at 2 points.

3 Possible Locations for a Light Switch

It’s when you have a much grander room that a four-way switch starts to make more sense. In this stock image above, for example, I can see three places I would easily want a light switch for this room.

  1. Near the sliding glass door, or that wall across the hall from it at least.
  2. At the base of the stairs, so I can turn the light off or on as I come down.
  3. Behind the photographer where there is likely to be the front door or other entry-way.

Voila, there you have it, three switches to control one light.

Four-Way Switch Wiring

This type of switch is going to have four different terminals. Each terminal is going to have two pairs of travelers that accompany it; one set is generally going to be black while the other brass.

As previously mentioned, each four-way switch will also have two three-way switches on either end—therefore the four-way switch will sit in the middle. 

If you are looking to wire a four-way switch yourself, here are the steps:

  1. The first three-way switch’s brass travelers will connect to one pair of the travelers on the second switch which belongs to the four-way switch (this can either be the black or brass colored traveler).
  2. Whichever pair of the four-way switch’s travelers you did not just connect, will now connect to one pair of the third switch’s (belonging to the four-way switch) travelers. 
  3. The other pair of that third switch’s travelers will connect to one pair on the fourth switch’s traveler, which will belong to that second third-way switch.
  4. The fourth switch’s common terminal, that is connected to the three-way switch, will connect to the lights.

Wiring Diagram

For help visualizing these steps, refer to the diagrams on this website. On this page, you will find these steps, but will also see drawings of each switch and how to go about the connections.

This may be especially helpful for readers who learn better visually or for those who are attempting this for the first time and are not familiar with the layout of the switches. 

What Is The Difference?

A four-way switch differs from other switch types in a few different ways. First, the double pole switch. This switch is going to look very similar to the four-way switch; however, this has an on/off label, whereas a four-way switch does not. 

Double pole switches are still four-way switches because they are characterized by two single pole switches put together. In this system, two separate circuits are controlled by one switch.

Three-way switches primarily differ from four-way switches in that they have three terminals instead of four. These are going to control a light from two or three switch locations—for example, at the top and bottom of a stairwell or at the end of a hallway. 

Why Use 208v Instead Of 240v?

Using too high of a voltage for your space will cause a lag in your appliances and lighting. For example, if you are operating 240v when you should be using a 208v system instead, your house will likely take longer to heat up, your oven will take longer to pre-heat and your cycles on your dryer will be longer. Elements will produce 33% more heat than they are designed for.

Similarly, if you are using a 208v system when your space is designed to take 240v, you will experience 25% less heat from your appliances and elements than you would if utilizing the correct voltage (source).  

However, if you mismatch your systems, this will shorten the lifespan of your appliances. In addition, this may cause a fire hazard if your appliances are running hotter than they are designed for. This is increasingly likely in the case of your dryer.

The most important thing to consider before operating a certain voltage is what your space and appliances are set up to hold. If you do not use the proper voltage you are putting the life of your appliances, and yourself at risk. 

For those who are more versed in electricity, the main difference between 208v and 240v is the phase system. 

  • 208v—this voltage is going to function on a three-phase system. The transformers here are going to be connected in a Wye configuration. Additionally, with this voltage, you can use a double-pole, single-phase circuit, or a three-pole, three-phase circuit with 208 volts between each phase. If you are using a single-phase circuit the voltage potential is going to be 208 volts between phases. 
  • 240v—this voltage system can be generated from a single-phase or in a three-phase system. 

Incorrect Voltage Use

Be very cautious of using the wrong voltage for your system, or overloading your breaker. If your voltage is exceeding what your switches and panel can handle, you may experience a variety of dangerous outcomes. 

If you overload your voltage, you may experience issues with your lighting and appliances. Be aware that this can cause flickering of your lights, which can also be a sign of a poor connection if you have just set up your switches. Consult an electrician for guidance on how to fix this problem as it is occurring.

However, if all of your switches and appliances are set up on a voltage higher than what the system can carry, they may burn out faster or heat slower. This is especially the case for appliances such as your clothes dryer, oven, stove, and hot tub. 

If you are operating these appliances on a lower voltage than they are set up for, you may experience decreased heat and functionality. If you are operating them at a higher voltage, they will get hotter but may take longer to heat up. This will also cause them to burn out a lot faster, requiring you to replace them with brand new appliances. 

Switch Types Based On Light Switch Count

When I was installing a three-way switch in the stairway down to my laundry room, the first thing my wife did was ask why it was called a three-way switch when it only worked with two light switches.

I understand that the terms “3-way switch” or “4-way switch” may be confusing at first. Ever wonder why they are called that? It is actually quite simple – a standard light switch has two terminals to connect the wiring, one for the hot side (power coming in) and one for the load side (the light).

When you have a 3-way switch there are three terminals, one for the hot or load side and the “travelers” that go between the two 3-way switches.

Four-way switches are the same concept, except that they have four terminals with two sets of travelers that will go between two 3-way switches or a 3-way switch and another 4-way switch.

As described above, you can have several 4-way switches in between two 3-way switches. But they never have more terminals, so you would simply have multiple 4-way switches in between the 3-way switches, but never a 5-way or 6-way switch.

Final Thoughts 

If you are looking to set up electrical wiring at a new home, office space, or project site, be sure you are very familiar with the difference between a four-way switch, three-way switch, and a double pole switch.

You will need to know which switch is required in certain areas of your project, and how they will function once set up.

Ensuring you have the correct voltage for the equipment you’re using is critical. If you have your voltage incorrect, your switches and other appliances may experience decreased functionality requiring additional support from an electrician to fix the problem you are experiencing. 

Keep in mind, if you do not have any training or expertise in electrical wiring, it may be best for you to outsource this portion of your project and hire a professional.

Electrical shocks can result in serious injury as well as death. Attempting to wire these switches without prior experience or training may not be in your best interest and have the potential to create a fire hazard if done incorrectly.

Rates for hiring a professional will vary, however, most electricians will charge between $50 and $80 an hour. If your project is relatively small, you will not be majorly set back by this hire. If your project is a larger scale, it may cost more for you to get additional help with your wiring. For more information on cost, visit this website

Tony

Hi there, my name is Tony. Having worked in the construction industry for over 30 years and being a weekend warrior on my own home I definitely have plenty of war stories to share. Have a topic or project you are interested in trying? Let me know and we will try to put together an article or video on it!

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