3 Way Switches, Explained

Three Way Switches In Detail

Hi everyone it’s your Edmonton Electrician here and today we are going to give you power through the knowledge of 3-way switches. These switches confuse many homeowners, and even some experienced electricians. As your friendly Edmonton electrician, we are going to explain them to you today. What they do, why they’re needed, and the different ways that they can be installed. Let’s get into it!

What is a three way switch? A 3 way switch is simply a switch that will control a load (usually lighting)  from 2 locations. Typical single pole switches will only control a load from one location. A 3 way switch is also known as a single pole double throw switch. When you need a load controlled from more than 2 locations, such as a long hall, or an area with 3 or more entrances, a 4 way switch is required. A 3 way switch will control from 2 locations, and with more locations than that, one or more 4 way switches will control the load from in between the 3 way switches. The main physical properties of these switches is different as well. Single Pole switches have 2 screw terminals for current carrying conductors. 3 way switches have 3 screw terminals for current carrying conductors. One is for the hot power source, and the other two are for what are called travellers. Travellers are the wires that make a 3 way switch system different from that of a single pole switch system. When you go further in depth an encounter 4 way switches they have 2 more differences. They have an additional current carrying conductor screw making for a total of four. The other difference is the cost. 4 way switches have a considerable cost difference to them when compared to single pole and 3 way switches. As your Edmonton electrician we like to plan jobs out in such a way to avoid having to many expenses such as multiple unnecessary 4 way switches.

Why do I need a 3 way switch?  The most common application for a 3 way switch is a lighting load controlled from different levels of a stairway. You would have one switch at the top, and one at the bottom. For multiple entry stairways you would add one or more 4 way switch in between these 3 way switches. Another common application would simply be a long hallway with two access points. Often if any room has multiple entrances 3 way switches would be used.

How can you wire a 3 way switch?

  1. Typically the easiest and most common method is to run 2 conductors from your source to your first 3 way switch. From there you would run 3 conductors to your next 3 way switch. Finally from there you would run 2 conductors again to your light. As your Edmonton Electrician this is the way we prefer to run our 3 way switch systems, as it makes troubleshooting the electrical in the future the most simple.
  2. Another practice for wiring 3 way switches is to again bring 2 conductors from your source to your first 3 way switch. From there you would bring 3 conductors to your lighting load, and from that light you would bring 3 conductors to your final 3 way switch. In this method you must pay close attention to the colour coding of your conductors to comply with the Canadian Electric Code. If this is something you are unfamiliar with it is always best to consult or hire an electrical contractor.
  3. The third common practice for wiring a 3 way switch is to bring your 2 conductor source to the light first. From here you would have 3 conductors going to one 3 way switch in one location. You would also have a second set of 3 conductors going to the other 3 way switch in the other location. In this method also you must pay close attention to the colour coding of your conductors. Complying with the Canadian Electric Code is mandatory and if not followed closely can cause electrical faults, and worse. If this is something you are unfamiliar with it is always best to consult or hire an electrical contractor. At Hauer Power we are always happy to assist our customers with their 3 way switch installations. If this is something you are having an issue with, call your Edmonton electrician today and book a free estimate.

So in summary there are 3 different ways to wire up a 3 way switch. The 3 different ways all have 3 things in common. The 3 different ways all have 1 difference.  The similarities between the 3 methods is that your source will be a 2 conductor system composed of a hot (usually black) and an identified conductor. Identified is commonly referred to as the neutral, which by CEC (Canadian Electrical Code) definition is incorrect. Regardless this identified conductor will most commonly be white. We only say most commonly because regardless of the colour of insulation the copper conductor will still act as a conductor. Due to this many DIY electrical jobs and unlicensed electricians will perform this with incorrect colour coding. Regardless of its working order illegal colour coding will make troubleshooting devices or circuitry in the future much more difficult. This could lead to more serious issues when electrical is installed incorrectly. As your Edmonton Electrician we at Hauer Power always perform our electrical work to comply with the current edition of the Canadian Electrical Code.

The other Similarities of the methods of installing 3 way switches is this. In all 3 cases The hot from your panel will go to your first switch. Finally your switch leg power will always go to your light.

The only real differences of the methods of installing 3 way switches are the location of where your devices can go, and in what order. As stated before pay close attention to the colour coding of your 3 way switch wiring when you’re not doing your lights last on the run. The different methods are often used simply to save on wiring costs. Whether it may be switch-switch-light, switch-light-switch, or light-switch-switch. Should there be a large physical span between devices and lights it may be worth it to have a look at which method of wiring your 3 way switches is best for you.

That’s it!  Remember if installing or troubleshooting anything electrical always de-energize your power supply and test before touching. If electrical issues are not something you are 100% comfortable with then it might be time to consider hiring a professional. Hauer Power, Your Edmonton Electrician is always here for a friendly honest and free in home estimate. Give us a call today!

Comments 2

Leave a Reply

Your email address will not be published. Required fields are marked *