Never have I ever heard this explained so elequently. As a handyman I ran into this working on my aunt's 70's townhouse when I updated the three way kitchen switches. I fumbled with this for 2 hours until I called an electrician to help. It took him about a half hour until he figured out the hot was in the light fixture and was able to wire it properly. Now I understand that this was a three way switch loop.
Sir, I have to tell you (from someone who never comments) that I really appreciate your teaching methods. Very straight forward, never condescending. You can teach to complete inexperienced and seasoned electricians alike. As someone who teaches and also is electrician, I must give you credit for this great work. Thank you for delivering content that actually empowers and encourages others.
Dustin, another great video except..... 200.7(C)(1) "If used for single-pole, 3-way or 4-way switch loops, the reidentified conductor with white or gray insulation or three continuous white or gray stripes shall be used only for the supply to the switch, but not as a return conductor from the switch to the outlet." from the NEC copyright NFPA. I love you videos and even use some of them in my 4th year apprentice class. Keep up the great work.
That one almost bit me (NEC 200.7(C)(1)) last week when I was installing a stairwell light controlled by 3-way switches. Sure glad I looked it up, otherwise there is no doubt I would have used the re-identified white wire as a return!
As a 30 year vet of electrical work, It is always feed down on the white and up on the black! The reason is that when you see a white tied to a black in the ceiling you know its a down feed to the switch and the black remains a known hot that is hooked up on the device. Down on the white Up on the black!
Yep. NEC 200.7 makes it a requirement. I'm a newb apprentice so I can't say for how long this has been in the NEC although it is *really* common to find wires of whatever color used for whatever. It's a wild west out there. First time I've caught an error in a Dustin video. ;)
This was EXACTLY the video I needed for our 1969 home. I'm no electrician and I could not wrap my head around the white sitting in the switch box. Thank you!
I LOVE this content. This dude teaches the basic fundamentals of electricity better than most seasoned electricians can! I wish more people taught it like this. I feel it would definitely help apprentices better understand and therefore, engage more with the trade and to be better workers.
I ran into one of these three-way switch looped setups in a 1968 built home "out in the boondocks of Texas" just as you suggested. The lights hadn't worked in a long time, so they had been disconnected (they appeared to be old locations for pendant lights in a front sitting room). I wanted to restore the light switches to operating condition but had never seen anything like this. I ended up using a multimeter, and then this video, to figure it out. Of the two lights, one had it's travelers reversed and the other had a loose hot wire. After reinstalling lights and switches, it worked great and is now rather useful. Thanks for the helpful explanation! I'm installing a new three-way switch configuration in a different part of the house and have decided to just do it the simple, modern way. It makes me chuckle to think that, in 50 years, the next remodeler will have to solve two different configurations.
I own a 1872 house in the Boondocks that had two major add-ons done, one in the 70s and one in the 80s. After weeks of watching TH-cam videos on three-way switches, you are the first to explain what I found in the boxes-only three wires in each box! All the wiring in this house has that level of craziness and nothing matches today’s instructions or code books. Sometimes, I feel that I am living in a mousetrap, even though everything works. So, thank you for your excellent explanation. Retired now, I was a vocational instructor and very much appreciate the clarity of your presentation.
I am a retired handyman. Love your videos. On several occasions I came across three way circuits functioning wrong. Flip one switch and the light works. Go to the second switch and nothing happens. Flip the first one back light goes out, go to the second and light comes on. Return to the first switch and nothing happens. I eventually would find the right way to change the wiring to fix it, but perhaps you might do a video showing what is going on for others here.
Hey Dustin so I’m an old electrician I did my apprenticeship in New York and Connecticut in the late 80 and early 90 and we did tons of those and dead end 3-ways and we never reidenified the neutral and I never got called out on it because it was just the normal way to do it. Now I mark everything how times change. Your a great teacher wish there were guys like you back then it would have moved our craft way further faster keep up the great work and don’t get burned out.
As an old (retired) electrician I find your videos good learning tools, only one critique. On your single pull ceiling fed drawing you should have fed the switch with the white wire not the black, We did not mark wires in the old days. Even though you indicate (with tape) the wire as a current carrying conductor if you open a box and see a black-white connection you know. Also in knob and tube houses it was common to switch the grounded conductor (neutral) which can cause pain for young electricians who rely on turning the switch off to change a light fixture.
Outstanding buddy I spent nearly a full weekend trying to fit new 3-way switches for the Mrs. Of course it was a perfect storm!... I'm Brit! now in Canada, we do it differently, just a DIY bloke, the house is almost a hundred years old with 70s wiring, no re-identification marks, and guess what, it was a 3-way, switch loop! Your video of the 3WSL was the only one I stumbled across, not knowing what to search for! I was at least gratified to hear you say that your electrician was confused. Magic, her switches now work. Thanks
I’ve come across this twice in California and both times I figured it out thru process of elimination. But you made it clear how the current travels. So thank you for being so informative.
The switch loop explanation is awesome. Years ago, we rented a 1950s house that had a garage breezeway light that could be switched on or off from any of FIVE different switches -- garage, kitchen, porch, downstairs hall, and upstairs hall. We wanted to open the walls to see how the hell it was wired. Now I'm beginning to see how it might've been done.
I once owned a house that had a 3-way switch loop, and I never could quite understand what was going on. Your drawing and explanation cleared that up. Thanks for the education!
I believe this just solved the problem with a 3 way that I haven't been able to get to work no matter HOW I wired it up.. JUST in time before I gave up and spent a crap ton of money too. THAAAANK YOUUU
Many older homes used lights with a pull-chain for the light, thus the habit of running power to the light. Then when they started using switches, they just ran the loop to the switch, often called a "dog-leg". Today, it is common to run the hot to the switch location and "loop" the light.
I remember reading somewhere, that back in the 1890s - very early 1900s, the few homes that were electrified would often have combination gas/electric light fixtures as the electric grids were sort of unreliable, and it was thought that electricity was a fad.... better keep the gas flowing, and usually consisted of a pendant light in the middle of a room, with a turn key switch, mimicking turning on a gas light fixture, when electrical appliances first appeared you would unscrew a bulb, then power your toaster or flatiron, etc from the lamp socket, early appliances often had a screw shell attachment plug on its cord. If an appliance cord had a pronged plug you screw an adapter into the socket, then insert the plug (base and cap) Some old timers still use the term plug cap or cord cap.
@@Sparky-ww5re In some places they fished wires thru the old gas plumbing. This is why lamp sockets and so many other things use standard 1/8" pipe threads. A switch on the socket reduced the complexity of the retrofit.
@@Sylvan_dB interesting, never heard of running wires through gas pipes, only heard of running wires alongside gas pipes, when homes has a combination of gas and electric lighting. that explains why metal conduit like Rigid Metal Conduit has couplings and threaded fittings very much like black iron piping. Ironically I have worked with metal conduit a couple of times , as well as working with black iron pipe adding a gas line for a range during a remodel project so a dual fuel range could be used, and became curious as to why the threaded fittings seem very similar, but never thought to do further research
My house was built in 1960. It has the power running to the switches, and a 12/3 running up to the lamp box with an always hot red wire presumably for ceiling fans to allow the fan to keep running even when you turn the light switch off. I have 4 ceiling fans configured that way.
I have a special situation 😊 maybe you can help. I’m in an old duplex with old wiring. They converted it from fuses to a breaker panel (hybrid) Any way….. 2 lighted single pole switches one at the top of the stairs one at the bottom to control the hallway light. There are only two wires, white and black. How do i get 3 way function out of this horrific setup? I haven’t attempted to locate the hot supply yet. I’m willing to bet it’s coming in from the ceiling as described in the video. I hate how they ran electrical back then
This is exactly the issue I have with my house made in 1972, I have been beating my head against the wall trying to find out what was going on with my wiring. Now I know it's a 3 way switch loop. Thank you!
Thank you for this! Could not figure out how a three way was working until I watched your portion on a 3 way switch loop! No relabeling of the neutrals as hot. Now I know why it works and can label it properly for future work
Exactly the info I needed. I just found a 3 way switch loop when replacing a ceiling light and had no idea why my two reds were wired together in the box. My place was built in 1979 in a major city.
Hey Dustin, Effin Awesome! I’m not an electrician. This is without a doubt the best electrical instruction channel on TH-cam. That white board along with your style of teaching explains these circuits in simple easy to understand terms. Thanks for all you do.
@@keything8487 Hey Key, John Q here. I may not be an electrician but I do take it very seriously. I have been doing my own and friends home electrical stuff for over 30 years. Admittedly have done my share of head scratching over the years. And yes, I also admit I must have had some luck. Having said that, there’s no shortage of John Q’s like me out there, and videos like this can only inform and help those of us that are not trained electricians, gain a better understanding of what is required and how to do it safely. I wish I had access to information like this back then.
@@EzRay11 i understand, i have seen first hand too many home/store owners get in over their heads (quickly).....and it never turns out well......for educational purposes, i like the video, im just afraid it ight empower some folks (hold my beer types) to bite off more than can be "chewed"....nothing personal against you.....not everyman/woman is capable.
Hey, Dustin, very good video. You keep getting better at explaining these concepts. The digital whiteboard is a big step up. A tiny bit of constructive feedback, if I may: Even though I already thoroughly understand this material it was a little confusing to me, as a "visual learner", to follow the drawings at times. Use a coil in a circle to represent a lightbulb. The architectural symbol with its four protruding wire-looking things is unnecessarily busy. It took me a second to realize that the light fixture is supposed to be in the ceiling box and not in a different location. Consider using a light grey as a background or outline color to define the boundaries between different locations or areas. Finally, When possible redraw the conductors on the side they're entering an outlet rather than drawing in 'hops'. This will help declutter the image.
Before I started watching your channel anything electrical scared me so I never dared touch it and this stems back to a bad shock I got when I was 20. Now I do my own electrical (simple residential in my own places only) and licensed electricians say they like my attention to detail. You're an awesome teacher and this video is an awesome troubleshooting and explanatory video.
This is great information and expertly delivered. Thank you so much. I liked and subscribed even though this is the only video I needed to see. I'm in the boondocks with a 1970s house. Near impossible to get an electrician out here. I've all but broken my brain on what the heck was going on until I saw this and realized what I had was a bunch of 3-Way Switch Loops!! Didn't even know that was a thing! Thank you so much. All problems solved =D
I must say you have an elegant way of teaching people and it is absolutely outstanding. I did not learn anything from watching your video I knew all this already but was just Amaze how well you are able to explain this to somebody who doesn't know. Kudos to you for your teaching abilities.
I am not an electrician, but a long time electrical DIYer. I have two comments: 1. I am old enough that I think the "3-way switch loop" was the way I was originally taught how to do 3-way switches! 2. This was, by far, the best white board (non-hands-on) explanation of 3-way switches I have ever seen. The only thing I would tweak is for the 3-way switch loop, the drawing might lead someone to believe that the "travelers" all connect to the light fixture when they do not. For clarity I would draw those outside the light electrical symbol since they connect (like you said) by wire nutting them together in the box. The only wires in the electrical box that connect to the light fixture are the relabeled common (white wire with black electrical tape usually) connecting to the hot side of the light fixture and the actual common connecting to the common side of the light.
I appreciate your work. I have been having problems with my lights since I bought the house. The wires were connected wrong in the same manner as your demonstration. Got it fixed.
Very well done. Had a very old house and while I had no idea what it was called... I was putting in all those switch loops everywhere as I went around and replace the pull strings with wall switches (2 and 3 way). Good to know I did it correctly ... wasn't so sure at the time!
How are you doing DUSTIN, I just wanted to thank you for your excellent teaching and great talent that you possess to explain step by step how to resolve the problem and to identify the problem THANKS FOR YOUR GREAT PATIENCE, QUEENS NEW YORK SAY HELLO 👋......THANKS AGAIN
I cannot express how helpful this video was. I just purchased a home built in 1900 and the entire home is wired with switch loops and even some 3 way ones. I am working on replacing the remaining knob and tube from the third floor down (adding a sub panel up there) and now that I have a better understanding of 3 ways I think I can get more loads off the old wiring than I had planned. I have 3 floors and each of those has a 3 way hall light that spans both floors with a 3 switch panel on the second floor that can control all 3 of those lights. That 3 switch panel (and almost every other switch in the house...) is ONLY hot wires and I have yet find where it is fed from, so I am now wondering if I can break that circuit up more by feeding at least one of the 3 ways from the other end. Thank you!
I've occasionaly come across this in older homes here in NY and leaves a much more crowded ceiling box. If you already had it wired with a single pole switch loop it is much easier to add a 3 way by simply running a 3 wire from the existing single pole switch to the new 3 way. Its still a switch loop running through the added 3 way and changing the single pole to a 3 way. Much cleaner and in fact can be made into 4 way, 5way etc by daisy chaining additional switches with additional 3 wire.
In my 50 plus years as a sparky never heard of a 5 way. You can have two to whatever you need 4 way switches wired between two 3 way switches. Had a gadget nut that we had to install outdoor flood lights from 5 locations in his big house. Best location was right next to his bed slightly higher then top of end table so he could turn on luminares without getting out of bed. Had to add a fancy timer, photo cell and a 4 position switch to select what he wanted to control Linares. Fourth position was bypass to keep bulbs lite while replacing them.
Thanks for the explanation. Under 2020 (I think-may have been earlier) switch boxes are required to have a neutral ot be able to be retrofitted with a neutral without cutting finished material. Just something to watch out for.
based on research this was in 2011. there are certain exceptions, one being three and four way switches, if the lighting layout is such the the lighted area is visible from all switch locations, a neutral shall be required at one of the locations. Meaning you can legally wire a dead end three way, or wire power to the first three way, then to the light, then a 14/3 from the light to the second location, and still meet code. Keep in mind that the AHJ may be more stringent than the NEC and require a neutral at every switch box.
@@davidsoulsby1102 great question, glad you asked! The reason for the neutral in the switch box requirement, is because nowadays, there are many types of switches that require a neutral to function. For example, certain dimmer switches, particularly Magnetic Low Volt and Electronic Low Volt when used with certain LED drivers, timeclock switches and Wi-Fi smart switches that connect to your home Wi-Fi for the purposes of home automation, all require a neutral to work. In older homes, say built before 2000, but especially in the 60s and 70s, it was common to find switch boxes without a neutral available, since electronic switchs did not yet exist, and a neutral was never needed, and in certain wiring layouts it used less material and/or labor to wire power to a light fixture, then drop a 14-2 or a pair of 14/3's down and give the switch the number of wires needed. later on it was found that homeowners wanting to bring their home up to the 21st century, would begin adding switches that need a neutral, but because there was not a neutral available, would use the ground as a neutral, putting unwanted current on the equipment grounding conductor. Hope this explanation helps.
So... House built in NVA 1976 and ran into this, wanted to hang outlet off one of the switches but..... hot feed from overhead light with a three was switch loop no neutral in the switch box. Messed with my head. Thanks for the understanding.
And that's one of many reasons why modern practice is to run your incoming power into a switch box, then run your 14-2 to the light. Also, there's a number of electronic switching devices that require a neutral to function properly. In the old days this wasn't a problem because electronic switches did not exist, you were simply making or breaking the circuit.
I had this same setup. I was simply trying to replace a light fixture. I noted extra wires in the ceiling box. I knew that it I simply disconnected the wires from the fixture and reconnected the same to new fixture all would work. And it did. However I drew a simply diagram to understand more as I knew that the fixture was controlled by two three way switches. After shutting off the power I did continuity tests to determine which wire was going where. And the two three ways were in gang boxes with others 3 ways for different fixtures. I did not hang the new fixture until I understood the flow. And I kept the diagram I drew so I would understand in the future if I changed out the fixture again. Side note: switch loops are a great example of why you should always turn the circuit off at the breaker. Turning off the switch would not stop the fixture box from being hot. I’m a diy homeowner. So I try to research as much as possible. And draw pictures and think before touching anything in a dangerous manner. Thanks for an excellent video.
You mentioned the remote control 3 way devices in the beginning. I recently used one of those and realized that the wired unit draws power all the time to sense the remote switch. If it is wired as a switch loop, this will result in the light receiving a very small amount of current, even when off. For an LED fixture, this results in a small amount of light. The 2020 requirement of having neutral in the switch box solves this, and now I "get it".
Actually you are a bit mistaken. That issue is not due to it being a switch loop. Because regardless the switch is hooked into a Hot and a Switch Leg. What's actually happening is that your light doesn't provide enough Load/resistance for the switch. The electronic switches actually NEED a load to function. Because to keep the electronics running inside, It needs a complete circuit. Using the light as a path to neutral But there is a minimum load of about 15-30 watts I believe If it is below that, the switch functions, but the resistance of the light isn't high enough to eat up that stray voltage coming through from the switch Some switches have a Neutral wire or terminal to alleviate this issue. But another solution is to A: install higher load lights or more of them. Or B: lutron makes a little minimum load capacitor that you wire in either at the switch or in the fixture box to the switch Leg and Neutral, and it supplies a little load of it's own to take care of that stray voltage
Another switch loop is if you need to add a switch to an existing one switch circuit with the hot in the switch box, is where you change the switch to a 3 way, then run one 14/3 wire to your second switch, and have the white return to the original switch box, and connect the original leg to the light to the white return from the second switch
Here in Belize that is the method used to distribute power to light switches and receptacles. The source comes from outlet boxes on the ceiling then to everything else. Nice video!
Great video. My son has the same 12 /2 wiring in his house no grid. Had no idea when I installed new dimmer when I found just white and black on the line and load side of the single pole??? Switch loop?? Excellent lesson
Before this awesome explanation, I wired up the lights and the outlets accidentally to turn on and off together. But obviously, the outlets need to stay on at all times, and the switch is only supposed to turn on the light. Excellent explanation.
My Uncles house has a 3 way switch loop like this. It never worked correctly. One of the switches went bad so I switched it out for him and noticed it wasn’t working correctly. Told me it was always like that. I couldn’t leave it like that lol. Took some time but I figured it out. He was happy after 30 years it was finally working correctly haha.
My house was built in 1995 in NYC! It has been a nightmare trying to upgrade to a smart home! Every switch in my home has used the white neutral as a hot, even in three ways. The switch loop that Dustin explained is exactly my scenario. Please do a video showing some fixes. I have invested so much money in smart fixtures just to have them sitting around with no solution. Dustin you are the only one I trust to show me the proper way to remedy this Mess.
👏🏻 truly clearly understood, avoiding the 😵💫…everyone not in the know, should keep this video for reference not if, but when you stumble onto this in your work adventures.
In the UK we use the loop system as standard. Well, we did until recently when the need for a neutral at the switch became the norm. For the 3 way (we call it 2 way) it's possible to connect the constant and switched lives to the two switched terminals of one switch and then run a 3 core (+earth) cable directly from that switch to the other switch with one conductor connecting the two commons together and the other two connecting to a switched terminal each in either switch. Sleaving must be used to reidentify conductors but cable with two browns (live/live) is common.
Man I use you back early years as a electrician in THE 70'S The first time I ran into a 3 way switch loop I was working on the house that was wire in knob and tubing long story short I figure out what going on You did good job explaining how a 3 way switch loop works Yes in today their many historical home that still wire in knob and tubbing
Great video! Thank you for your time and energy. I love your style and appreciate your delivery. I have a special situation 😊 maybe you can help. I’m in an old duplex with old wiring. They converted it from fuses to a breaker panel (hybrid) Any way….. 2 lighted single pole switches one at the top of the stairs one at the bottom to control the hallway light. There are only two wires, white and black. How do i get 3 way function out of this horrific setup? I haven’t attempted to locate the hot supply yet. I’m willing to bet it’s coming in from the ceiling as described in the video. I hate how they ran electrical back then
I've got several 3-way switch loops on my property (1985 house and out buildings). As I understand it, these don't meet code for new work because they don't provide a neutral for a smart switch. And that's exactly what I want to do, but without that neutral (or really violating code by using the ground as neutral for the smart switch :) ), I can't replace them. And to make matters worse, these are in areas that aren't accessible unless I start cutting holes in the ceiling.
You seldom have to bring such things up to present codes unless performing major renovations. Hopefully you still can purchase devices that utilize the ground wire for probably less then a milliamp of power. We were told at an IAEI continuing education class that one of the reasons for requiring a white grounded conductor ( no such thing in NEC anymore as a neutral ) was that in cases where people had a lot of them feed from a GFCI the slight imbalance between the hot black conductor & the white wire would exceed the 4 to 6 milliamps needed to trip a GFCI. If switches are in open basements or in conduit then a white wire is not necessary because it's easy to install one in the future.
I love how you explained all this, but I would love for you to blow everyone's minds and diagram out a FOUR-WAY switch for when someone wants three, four, five, ten switches for one light!
I'm not sure what the NEC says on the subject, but in the Canadian Electrical Code it says if you use "premanufactured cables" (NMD, BX, whatever) for switch loops, you have to use white as your "unswitched conductor" (aka, hot) and black as your switch leg. Also, in 2018 it was added that any switch for lights had to have a neutral present in the box (even if it's not being used, it's for if somebody wants to add a dimmer later that requires a neutral), so now you have to use 3-conductor instead of 2 for switch loops. I haven't seen or heard of a 3-way switch loop so far yet in my short career in electrical, but it's good knowledge to have for sure. I love these theory videos and learn a lot from them, thanks Dustin!
When working in older homes with fiber insulated wires and plastered walls these switch loops are very common. Many original fixtures only had a switch on the device itself. Lucky to see a actual wall switch to have been added at all over the course of their many renovations.
I'd be interested in knowing how you would install "smart" or "IR Motion" 3 way switches in this the 3 way switch loop scenario. Most of the smart or motion switches on the market require a neutral wire which doesn't exist in the switch box. I discovered this, much to my dismay when installing smart switches in a home I purchased which was built back in the 80's. Excellent video as per usual. I started watching you when I embarked on this journey to update my new home. You are an great resource.
in the 3 way switch loop scenario shown, you would reconnect the loop wiring - each 3 wire loop wire would revert to hot, neutral, switched. then each motion sensor switch would be hooked up like a single pole, and the both red (switched) leads would connect to the light. best to have a contactor model of motion sensing switch for that, rather than solid state, since some solid state switches don't respond well to a backfeed.
Im totally gonna look and see if its already a thing, but while i have it fresh in my brain i was looking for a more detailed video on the differences between transfer switch and interlock. again if youve already made then thank you in advance! good vids brother cant wait for the next
Great content, downside is if you want “lighted” switches, or if you want to replace them with “automation” computer controlled switches. But again great style and presentation of content.
I did a 3 way loop on my house, when I built it. The main reason I did that was because the wiring was getting pretty busy in the walls. Took a little head scratching to figure it out, since I have never done one of those before but it worked out great.
Do you have a video, or diagram, of how I would hook up a switch leg when there are wires in the box that are also going to outlets? Then I have another wire that is going to another light that I would like to be able to control with the same switch, but there are also wires in that box running to outlets.
Utah small 50s-60s homes with basements, with about 1600-2000sf total, used switch loops, running first to the single light box, then separate wires, one to the four receptacles, and one to the light switch. For small 11ftx11ft rooms with one ceiling light this makes sense in order to isolate each room to one circuit. I completely re-wired the house in order to add a bigger service panel, get a main circuit breaker, add ground wires, and add more circuits. The tight layout of the house and all the load bearing walls made the most sense to keep most of the rooms the same size. It also seemed to make sense to keep the circuits in this loop to isolate each room to one circuit. The two larger rooms and kitchen were wired conventionally. Not everyone has a fancy new large home 3000sf+ and 1960 isn't that old. I kind of chuckle thinking that code (and electrician advertsising carring most about taking your money) makes it sound as if an original 1960s home will burn up or kill you at any moment and that the older fabric insulated NM copper wire is surely rotted, leaking, and arcing. All of mine was was just fine, likely less of an issue in Utah's dry climate.
Excellent video as usual. Succinct and clear. It seems like one way to identify a 3-way switch loop in cases of confusion would be that there's two cables coming out of the light box, right? Two sets of 15-2. You could check it from above or pull it out of the ceiling and check.
@@NickFrom1228 in this case, when there is a single pole switch loop done to meet Code, the white in the 14/3 will be tied to the neutral in the light box, capped off in the switch box, the black is the hot and the red is the leg. I've used this method in remodels, to add a switch to a pull chain fixture. In new construction I always wire the incoming power to the switch box, makes troubleshooting easier if there's a problem later on, saves from having to get a ladder, even if it means using a little more wire.
@@Bapuji42 Probably, but I don't want to say this is the only reason you would see it. There is probably some scenario out there where you would see this but I can't think of any offhand.
THANK YOU very much for this video! I managed to reverse engineer / forensically deconstruct this exact setup in my PacNW house that the original long time owner had rednecked his electrical over several decades and 5+ additions and renovations. It's nice to see how it was originally intended to have been installed; it explains why his janky/kludgy repairs were done that way. I may not have even been a certified electrician but I'm not afraid of an NEC code book and have been bringing circuits up to modern safety standards as I find his installed fire hazards. Except the THREE breaker box situation with a "main" breaker panel and two mini breaker panels. The first mini breaker box was fully Zinsco parts but only the left side was used ... so they covered the punched out right with duck taped cardboard. Oh: it also may or may not have been wired in on the street side of the meter. I hired a professional (the 2nd most expensive and well recommended) to make this problem safe and legal. I can deal with science but not the law. The original owner just seemed to add copper until the lights came on.
Thanks for you video. I have an issue that might be "switch loop." the dining room Chandelier was the old type, no neutral, just look like brown extention cord wiring. It was be control with a smart dimmer switch. When I look in the ceiling box, there was three wires, black, white and ground. On the old light fixture, the wire that was connected to the white in the ceiling from the old fixture had black tape on it. Before this video, I tried hooking up the new fixture like you normally would but as you may already know, that did not go well. I blew 4 smart switches from tplink before I gave up. What I don't see that your video describes is an additional set of wires in the ceiling. What do I do? Also, I noticed when testing what was the power coming from any of my outlets was above 240. I know that's not normal so I disconnected the wires from the switch and turned of the breaker until further notice.
A few years back we came across a five way switch loop, that a renter had replaced one of the switches in. I took a full day to figure it out and get it wired so it worked. We had to find an easel with a 3X4-foot pad of paper on it, set it in the room we were trying to figure out, and diagram the whole mess before we figured it out.
As an American living in the UK working as an electrical design engineer(I'm the guy you hate haha) , switch lives is mostly what I'd used here. However I tend to work on large commercial projects and they tend to use ELV switching instead. Great videos!
Is it feasible to do a 3 way switch loop with 2 wire cable from the ceiling box to each switch box.. and 3 wire cable ran between each of the wall switch boxes? Again, two, two wire cables from the ceiling box where the hot enters, to two boxes where 3 wire cable connects between the two boxes. Thoughts?
Thanks for this. My house was built in the 60's when they sent copper to Vietnam and put aluminum wire in houses. I wanted to put in a socket, assuming I could get a hot wire from the switch. The result was lights flickering when using the socket. Now I know It was the hot just run down from the ceiling powering the vacuum through the lightbulb.
Great video was having a hard time trying to understand how to hook up a 3 way WIFI switch with no nutral wire in both boxs, THANKS TO THIS VIDEO I now know whats in my two 3 way box switches for the basement lights , back in the day someone used two 14/3 wires in each switch box the colours are black, red, white, whey used red & white as travlers, the 14/2 power wires are in a junction box in the closet ceiling, the hot black is together with the 14/3 black on the upstairs switch, the black wire in the basment switch box is the load wire to the light wire, and the 14/2 white nutral wire in the junction box is together with the white wire for the lights . Hope this makes any sence, unfortunetly i was not able to hook up the 3 way WIFI switch because of no nutral wire, i did hook up a Leviton DSL06 dimmer switch, But the switch has a low humming sound coming from it, lights turn on and off, and dimmer works fine, Just dont know why the low humming from switch ?
Last year I came across an interesting loop. I didn't know it was a loop at the time. Situation: hallway, three single switches (one on each end and one in the middle). Someone decided to upgrade the switches and instead of replacing the old yellow 3-way switches with new white ones, they installed 3 single-gang switches. I had conductors on the grounds!!. This mess had wires connected together that shouldn't have been and some capped off and yet no breakers were tripping. So I removed the switches, pulled all the wires out and identified them with continuity checks. So it was actually a 4-way loop. It took a couple of days to wrap my head around it, since the power came in from the light fixture in the middle of the hallway but I finally got it all working. Man, what a learning opportunity!!!
Very interesting how different places have different ideas. I'm in the UK, the switch loop as described here is how is how it's always (rare exceptions) done, a ring from the fusebox to the first light then looped to next then the next etc until the last goes back to the fusebox. At each light a 2 core cable (twin and earth) goes down to a switch with the red (live or hot) to the common connection and the black (neutral) to the sw1 connection and marked with red tape, at the light box/chamber the red is connected to live incoming ring and the black with red tape is connected to the fitting live connection. All neutrals are bunched together. What is being called 3 way on the video is what we call 2 way and instead of having wires from the light to each switch we have 1 to the first sw then from there a 3 core cable (3 core and earth) goes to the second switch. Hard to describe but think of it as like the 3 way switch loop here but missing out the light fitting. 3 way switching here is where you has as described above but with an intermediate switch between switch 1 and switch 2, think of a crossover switch. You can put in as many intermediate switches as you want and just call it by how many switches are there eg 5 way 6 way..... To surmise you have a ring of light fittings, each fitting has 1 cable to a switch, then if its 2 way you just run a cable from the switch to the next switch and so on, Radials you could describe them as.
I wonder if THIS particular video might be served with a follow-up video where a set of physical light switches and a light are used, with the appropriate ROMEX is used between all of them? That might clarify the illustrations.
In the 3-way, what purpose does the ground on the leg side switch serve (since there's no ground connection from leg to hot side)? Could you just use 12/2 for the leg side run?
same as everyone.. thanks. I knew the mechanics of them but didn't get the understanding until this video. I watched another a while back when you guys taught me that there is code for the number of wires that you can have in a box. wouldn't you break that code since normal 3-ways at the box only 3 conductors: hot, common and ground. with the 3-way switch loop you would now have 11 if you include the ground for all of them: source: common, ground, hot for each leg:(hot, common, traveler, ground)x2
This is off subject. Do you have a video on how to build a proper pull head for larger wire like 3/0. I need some direction for easier pulls for larger wire.
Hey! Great video. However I think I have a switch loop in a new basement remodel where the whites were reidentified. The problem though is that the wires the electrician painted as hot weren’t being used as a common. The hot wire in one leg of this 3 way circuit was the black traveler. I’m totally confused by this. We are trying to setup Kasa smart switches and it’s been such a headache. Any advice would be appreciated.
Thanks for another great video. Whenever I am taught something I need to know how it all works and why. That is how I easily remember the lesson. This is exactly what you do so well. Could you do a video explaining how some devices require no neutral, yet obviously get voltage to operate their internal electronics? Like exhaust fan timer and smart dimmer switches requiring no neutral connection to operate. I have always thought I should only use these types of devices requiring neutrals, even if I have to repurpose a wire or run a new one to the box. I have a lot of smart dimmer switches installed but only use the version requiring a neutral.
some of those devices used to run their "neutral" through the fixture they controlled, which worked okay with incandescent lights, but can cause ghosting in LED bulbs, or degraded device function. the next generation uses the grounding conductor for their neutral, which, of course, can cause conflict with GFCI or AFCI protection. most of those will have a separate neutral and ground conductor, so they can be combined on the ground if necessary, but are best connected to the neutral.
Never have I ever heard this explained so elequently. As a handyman I ran into this working on my aunt's 70's townhouse when I updated the three way kitchen switches. I fumbled with this for 2 hours until I called an electrician to help. It took him about a half hour until he figured out the hot was in the light fixture and was able to wire it properly. Now I understand that this was a three way switch loop.
Sir, I have to tell you (from someone who never comments) that I really appreciate your teaching methods. Very straight forward, never condescending. You can teach to complete inexperienced and seasoned electricians alike. As someone who teaches and also is electrician, I must give you credit for this great work. Thank you for delivering content that actually empowers and encourages others.
Dustin, another great video except..... 200.7(C)(1) "If used for single-pole, 3-way or 4-way switch loops, the reidentified conductor with white or gray insulation or three continuous white or gray stripes shall be used only for the supply to the switch, but not as a return conductor from the switch to the outlet." from the NEC copyright NFPA.
I love you videos and even use some of them in my 4th year apprentice class. Keep up the great work.
That one almost bit me (NEC 200.7(C)(1)) last week when I was installing a stairwell light controlled by 3-way switches. Sure glad I looked it up, otherwise there is no doubt I would have used the re-identified white wire as a return!
As a 30 year vet of electrical work, It is always feed down on the white and up on the black! The reason is that when you see a white tied to a black in the ceiling you know its a down feed to the switch and the black remains a known hot that is hooked up on the device. Down on the white Up on the black!
Yep. NEC 200.7 makes it a requirement. I'm a newb apprentice so I can't say for how long this has been in the NEC although it is *really* common to find wires of whatever color used for whatever. It's a wild west out there.
First time I've caught an error in a Dustin video. ;)
@@ericgold3840 200.7 also requires that the white be reidentified to a hot color. Not allowed to leave it white anymore.
I agree, besides the code says you can't use the white for a switch leg, It has to be the constant hot if used on a switch
You as an electrician identify each wire at their termination points with tape or other means
😊😊p
This was EXACTLY the video I needed for our 1969 home. I'm no electrician and I could not wrap my head around the white sitting in the switch box. Thank you!
I LOVE this content. This dude teaches the basic fundamentals of electricity better than most seasoned electricians can! I wish more people taught it like this. I feel it would definitely help apprentices better understand and therefore, engage more with the trade and to be better workers.
Well that's exactly what I'm doing here. Lol
I ran into one of these three-way switch looped setups in a 1968 built home "out in the boondocks of Texas" just as you suggested. The lights hadn't worked in a long time, so they had been disconnected (they appeared to be old locations for pendant lights in a front sitting room). I wanted to restore the light switches to operating condition but had never seen anything like this. I ended up using a multimeter, and then this video, to figure it out. Of the two lights, one had it's travelers reversed and the other had a loose hot wire. After reinstalling lights and switches, it worked great and is now rather useful. Thanks for the helpful explanation! I'm installing a new three-way switch configuration in a different part of the house and have decided to just do it the simple, modern way. It makes me chuckle to think that, in 50 years, the next remodeler will have to solve two different configurations.
I own a 1872 house in the Boondocks that had two major add-ons done, one in the 70s and one in the 80s. After weeks of watching TH-cam videos on three-way switches, you are the first to explain what I found in the boxes-only three wires in each box! All the wiring in this house has that level of craziness and nothing matches today’s instructions or code books. Sometimes, I feel that I am living in a mousetrap, even though everything works. So, thank you for your excellent explanation. Retired now, I was a vocational instructor and very much appreciate the clarity of your presentation.
I am a retired handyman. Love your videos. On several occasions I came across three way circuits functioning wrong. Flip one switch and the light works. Go to the second switch and nothing happens. Flip the first one back light goes out, go to the second and light comes on. Return to the first switch and nothing happens. I eventually would find the right way to change the wiring to fix it, but perhaps you might do a video showing what is going on for others here.
Hey Dustin so I’m an old electrician I did my apprenticeship in New York and Connecticut in the late 80 and early 90 and we did tons of those and dead end 3-ways and we never reidenified the neutral and I never got called out on it because it was just the normal way to do it. Now I mark everything how times change. Your a great teacher wish there were guys like you back then it would have moved our craft way further faster keep up the great work and don’t get burned out.
You were probably the one who wired my home in NYC 1995! 🤨🥰LOL
As an old (retired) electrician I find your videos good learning tools, only one critique. On your single pull ceiling fed drawing you should have fed the switch with the white wire not the black, We did not mark wires in the old days. Even though you indicate (with tape) the wire as a current carrying conductor if you open a box and see a black-white connection you know. Also in knob and tube houses it was common to switch the grounded conductor (neutral) which can cause pain for young electricians who rely on turning the switch off to change a light fixture.
I REALLY struggled with reidentification of wires, and 3ways/4ways in general, cant express enough how much I appreciate you clarifying this stuff!!
Outstanding buddy I spent nearly a full weekend trying to fit new 3-way switches for the Mrs. Of course it was a perfect storm!... I'm Brit! now in Canada, we do it differently, just a DIY bloke, the house is almost a hundred years old with 70s wiring, no re-identification marks, and guess what, it was a 3-way, switch loop! Your video of the 3WSL was the only one I stumbled across, not knowing what to search for! I was at least gratified to hear you say that your electrician was confused. Magic, her switches now work. Thanks
I’ve come across this twice in California and both times I figured it out thru process of elimination. But you made it clear how the current travels. So thank you for being so informative.
The switch loop explanation is awesome. Years ago, we rented a 1950s house that had a garage breezeway light that could be switched on or off from any of FIVE different switches -- garage, kitchen, porch, downstairs hall, and upstairs hall. We wanted to open the walls to see how the hell it was wired. Now I'm beginning to see how it might've been done.
Wouldn’t it be a 4 way switch?
I once owned a house that had a 3-way switch loop, and I never could quite understand what was going on. Your drawing and explanation cleared that up. Thanks for the education!
I use to get zapped alot by this but yea great explanation.
That’ll be $3000, sir. Cash or credit?
I believe this just solved the problem with a 3 way that I haven't been able to get to work no matter HOW I wired it up.. JUST in time before I gave up and spent a crap ton of money too. THAAAANK YOUUU
Many older homes used lights with a pull-chain for the light, thus the habit of running power to the light. Then when they started using switches, they just ran the loop to the switch, often called a "dog-leg". Today, it is common to run the hot to the switch location and "loop" the light.
I remember reading somewhere, that back in the 1890s - very early 1900s, the few homes that were electrified would often have combination gas/electric light fixtures as the electric grids were sort of unreliable, and it was thought that electricity was a fad.... better keep the gas flowing, and usually consisted of a pendant light in the middle of a room, with a turn key switch, mimicking turning on a gas light fixture, when electrical appliances first appeared you would unscrew a bulb, then power your toaster or flatiron, etc from the lamp socket, early appliances often had a screw shell attachment plug on its cord. If an appliance cord had a pronged plug you screw an adapter into the socket, then insert the plug (base and cap) Some old timers still use the term plug cap or cord cap.
@@Sparky-ww5re In some places they fished wires thru the old gas plumbing. This is why lamp sockets and so many other things use standard 1/8" pipe threads. A switch on the socket reduced the complexity of the retrofit.
@@Sylvan_dB interesting, never heard of running wires through gas pipes, only heard of running wires alongside gas pipes, when homes has a combination of gas and electric lighting. that explains why metal conduit like Rigid Metal Conduit has couplings and threaded fittings very much like black iron piping. Ironically I have worked with metal conduit a couple of times , as well as working with black iron pipe adding a gas line for a range during a remodel project so a dual fuel range could be used, and became curious as to why the threaded fittings seem very similar, but never thought to do further research
My house was built in 1960. It has the power running to the switches, and a 12/3 running up to the lamp box with an always hot red wire presumably for ceiling fans to allow the fan to keep running even when you turn the light switch off. I have 4 ceiling fans configured that way.
I have a special situation 😊 maybe you can help.
I’m in an old duplex with old wiring. They converted it from fuses to a breaker panel (hybrid)
Any way….. 2 lighted single pole switches one at the top of the stairs one at the bottom to control the hallway light.
There are only two wires, white and black. How do i get 3 way function out of this horrific setup?
I haven’t attempted to locate the hot supply yet. I’m willing to bet it’s coming in from the ceiling as described in the video.
I hate how they ran electrical back then
This is exactly the issue I have with my house made in 1972, I have been beating my head against the wall trying to find out what was going on with my wiring. Now I know it's a 3 way switch loop. Thank you!
You have a way of explaining things that makes it so easy to understand. 3-way switching is a complex concept to most people, but it really is simple.
Thank you for this! Could not figure out how a three way was working until I watched your portion on a 3 way switch loop! No relabeling of the neutrals as hot. Now I know why it works and can label it properly for future work
Thanks dude, I'm a beginner and just 21 years old so having access to videos like this is awesome.
Exactly the info I needed. I just found a 3 way switch loop when replacing a ceiling light and had no idea why my two reds were wired together in the box. My place was built in 1979 in a major city.
Hey Dustin,
Effin Awesome! I’m not an electrician. This is without a doubt the best electrical instruction channel on TH-cam. That white board along with your style of teaching explains these circuits in simple easy to understand terms.
Thanks for all you do.
whats scary is john q home owner trying to do, redo these type joints, and hurting themselves, or others......or even causing a fire.
@@keything8487 Hey Key, John Q here. I may not be an electrician but I do take it very seriously. I have been doing my own and friends home electrical stuff for over 30 years. Admittedly have done my share of head scratching over the years. And yes,
I also admit I must have had some luck.
Having said that, there’s no shortage of John Q’s like me out there, and videos like this can only inform and help those of us that are not trained electricians, gain a better understanding of what is required and how to do it safely.
I wish I had access to information like this back then.
@@EzRay11 i understand, i have seen first hand too many home/store owners get in over their heads (quickly).....and it never turns out well......for educational purposes, i like the video, im just afraid it ight empower some folks (hold my beer types) to bite off more than can be "chewed"....nothing personal against you.....not everyman/woman is capable.
Hey, Dustin, very good video. You keep getting better at explaining these concepts. The digital whiteboard is a big step up. A tiny bit of constructive feedback, if I may:
Even though I already thoroughly understand this material it was a little confusing to me, as a "visual learner", to follow the drawings at times.
Use a coil in a circle to represent a lightbulb. The architectural symbol with its four protruding wire-looking things is unnecessarily busy.
It took me a second to realize that the light fixture is supposed to be in the ceiling box and not in a different location. Consider using a light grey as a background or outline color to define the boundaries between different locations or areas.
Finally, When possible redraw the conductors on the side they're entering an outlet rather than drawing in 'hops'. This will help declutter the image.
This explained everything I had questions regarding 3-way. Well Done. Thank you.
Before I started watching your channel anything electrical scared me so I never dared touch it and this stems back to a bad shock I got when I was 20. Now I do my own electrical (simple residential in my own places only) and licensed electricians say they like my attention to detail. You're an awesome teacher and this video is an awesome troubleshooting and explanatory video.
This is great information and expertly delivered. Thank you so much. I liked and subscribed even though this is the only video I needed to see. I'm in the boondocks with a 1970s house. Near impossible to get an electrician out here. I've all but broken my brain on what the heck was going on until I saw this and realized what I had was a bunch of 3-Way Switch Loops!! Didn't even know that was a thing! Thank you so much. All problems solved =D
I must say you have an elegant way of teaching people and it is absolutely outstanding. I did not learn anything from watching your video I knew all this already but was just Amaze how well you are able to explain this to somebody who doesn't know. Kudos to you for your teaching abilities.
I am not an electrician, but a long time electrical DIYer. I have two comments:
1. I am old enough that I think the "3-way switch loop" was the way I was originally taught how to do 3-way switches!
2. This was, by far, the best white board (non-hands-on) explanation of 3-way switches I have ever seen. The only thing I would tweak is for the 3-way switch loop, the drawing might lead someone to believe that the "travelers" all connect to the light fixture when they do not. For clarity I would draw those outside the light electrical symbol since they connect (like you said) by wire nutting them together in the box. The only wires in the electrical box that connect to the light fixture are the relabeled common (white wire with black electrical tape usually) connecting to the hot side of the light fixture and the actual common connecting to the common side of the light.
I appreciate your work. I have been having problems with my lights since I bought the house. The wires were connected wrong in the same manner as your demonstration. Got it fixed.
Very well done. Had a very old house and while I had no idea what it was called... I was putting in all those switch loops everywhere as I went around and replace the pull strings with wall switches (2 and 3 way). Good to know I did it correctly ... wasn't so sure at the time!
I really enjoyed this one i have done a single pole switch loop before but not a 3 way one this showed how it;s done I really appricciat it.
How are you doing DUSTIN, I just wanted to thank you for your excellent teaching and great talent that you possess to explain step by step how to resolve the problem and to identify the problem THANKS FOR YOUR GREAT PATIENCE, QUEENS NEW YORK SAY HELLO 👋......THANKS AGAIN
I cannot express how helpful this video was. I just purchased a home built in 1900 and the entire home is wired with switch loops and even some 3 way ones. I am working on replacing the remaining knob and tube from the third floor down (adding a sub panel up there) and now that I have a better understanding of 3 ways I think I can get more loads off the old wiring than I had planned. I have 3 floors and each of those has a 3 way hall light that spans both floors with a 3 switch panel on the second floor that can control all 3 of those lights. That 3 switch panel (and almost every other switch in the house...) is ONLY hot wires and I have yet find where it is fed from, so I am now wondering if I can break that circuit up more by feeding at least one of the 3 ways from the other end. Thank you!
Im a visual learner i love how you draw it out and explain im a hands on and the way you teach is 👍..
I've occasionaly come across this in older homes here in NY and leaves a much more crowded ceiling box. If you already had it wired with a single pole switch loop it is much easier to add a 3 way by simply running a 3 wire from the existing single pole switch to the new 3 way. Its still a switch loop running through the added 3 way and changing the single pole to a 3 way. Much cleaner and in fact can be made into 4 way, 5way etc by daisy chaining additional switches with additional 3 wire.
In my 50 plus years as a sparky never heard of a 5 way. You can have two to whatever you need 4 way switches wired between two 3 way switches. Had a gadget nut that we had to install outdoor flood lights from 5 locations in his big house. Best location was right next to his bed slightly higher then top of end table so he could turn on luminares without getting out of bed. Had to add a fancy timer, photo cell and a 4 position switch to select what he wanted to control Linares. Fourth position was bypass to keep bulbs lite while replacing them.
Great use of white boarding. Clear instructions. Really appreciate this channel and happy to subscribe and like.
Thanks for the explanation. Under 2020 (I think-may have been earlier) switch boxes are required to have a neutral ot be able to be retrofitted with a neutral without cutting finished material. Just something to watch out for.
based on research this was in 2011. there are certain exceptions, one being three and four way switches, if the lighting layout is such the the lighted area is visible from all switch locations, a neutral shall be required at one of the locations. Meaning you can legally wire a dead end three way, or wire power to the first three way, then to the light, then a 14/3 from the light to the second location, and still meet code. Keep in mind that the AHJ may be more stringent than the NEC and require a neutral at every switch box.
@@Sparky-ww5re
Thank you for the code clarification.
@@Sparky-ww5re From the UK. why do they stipulate a neutral in a lighting switch box please? its not used 🤷♀
@@davidsoulsby1102 great question, glad you asked! The reason for the neutral in the switch box requirement, is because nowadays, there are many types of switches that require a neutral to function. For example, certain dimmer switches, particularly Magnetic Low Volt and Electronic Low Volt when used with certain LED drivers, timeclock switches and Wi-Fi smart switches that connect to your home Wi-Fi for the purposes of home automation, all require a neutral to work.
In older homes, say built before 2000, but especially in the 60s and 70s, it was common to find switch boxes without a neutral available, since electronic switchs did not yet exist, and a neutral was never needed, and in certain wiring layouts it used less material and/or labor to wire power to a light fixture, then drop a 14-2 or a pair of 14/3's down and give the switch the number of wires needed. later on it was found that homeowners wanting to bring their home up to the 21st century, would begin adding switches that need a neutral, but because there was not a neutral available, would use the ground as a neutral, putting unwanted current on the equipment grounding conductor. Hope this explanation helps.
You are a great teacher. Thank you for making these videos. This was def the answer i was looking for.
So... House built in NVA 1976 and ran into this, wanted to hang outlet off one of the switches but..... hot feed from overhead light with a three was switch loop no neutral in the switch box. Messed with my head. Thanks for the understanding.
And that's one of many reasons why modern practice is to run your incoming power into a switch box, then run your 14-2 to the light. Also, there's a number of electronic switching devices that require a neutral to function properly. In the old days this wasn't a problem because electronic switches did not exist, you were simply making or breaking the circuit.
I had this same setup. I was simply trying to replace a light fixture. I noted extra wires in the ceiling box. I knew that it I simply disconnected the wires from the fixture and reconnected the same to new fixture all would work. And it did. However I drew a simply diagram to understand more as I knew that the fixture was controlled by two three way switches. After shutting off the power I did continuity tests to determine which wire was going where. And the two three ways were in gang boxes with others 3 ways for different fixtures. I did not hang the new fixture until I understood the flow. And I kept the diagram I drew so I would understand in the future if I changed out the fixture again. Side note: switch loops are a great example of why you should always turn the circuit off at the breaker. Turning off the switch would not stop the fixture box from being hot.
I’m a diy homeowner. So I try to research as much as possible. And draw pictures and think before touching anything in a dangerous manner. Thanks for an excellent video.
You mentioned the remote control 3 way devices in the beginning. I recently used one of those and realized that the wired unit draws power all the time to sense the remote switch. If it is wired as a switch loop, this will result in the light receiving a very small amount of current, even when off. For an LED fixture, this results in a small amount of light. The 2020 requirement of having neutral in the switch box solves this, and now I "get it".
i have that problem with a motion sensor light switch light glows when in sensor mode but is off if you turn selector to off
Actually you are a bit mistaken.
That issue is not due to it being a switch loop. Because regardless the switch is hooked into a Hot and a Switch Leg.
What's actually happening is that your light doesn't provide enough Load/resistance for the switch.
The electronic switches actually NEED a load to function.
Because to keep the electronics running inside, It needs a complete circuit. Using the light as a path to neutral
But there is a minimum load of about 15-30 watts I believe
If it is below that, the switch functions, but the resistance of the light isn't high enough to eat up that stray voltage coming through from the switch
Some switches have a Neutral wire or terminal to alleviate this issue.
But another solution is to A: install higher load lights or more of them.
Or B: lutron makes a little minimum load capacitor that you wire in either at the switch or in the fixture box to the switch Leg and Neutral, and it supplies a little load of it's own to take care of that stray voltage
Excellent video. Only thing that could be added is to add the ground between in the traveler and explain the pigtailing in each box.
Another switch loop is if you need to add a switch to an existing one switch circuit with the hot in the switch box, is where you change the switch to a 3 way, then run one 14/3 wire to your second switch, and have the white return to the original switch box, and connect the original leg to the light to the white return from the second switch
I've always called this a dead end three way. you can also do the same thing with a single pole switch loop.
Yep done that plenty of times
Here in Belize that is the method used to distribute power to light switches and receptacles. The source comes from outlet boxes on the ceiling then to everything else. Nice video!
Great video. My son has the same 12 /2 wiring in his house no grid. Had no idea when I installed new dimmer when I found just white and black on the line and load side of the single pole??? Switch loop?? Excellent lesson
Before this awesome explanation, I wired up the lights and the outlets accidentally to turn on and off together.
But obviously, the outlets need to stay on at all times, and the switch is only supposed to turn on the light. Excellent explanation.
My Uncles house has a 3 way switch loop like this. It never worked correctly. One of the switches went bad so I switched it out for him and noticed it wasn’t working correctly. Told me it was always like that. I couldn’t leave it like that lol. Took some time but I figured it out. He was happy after 30 years it was finally working correctly haha.
My house was built in 1995 in NYC! It has been a nightmare trying to upgrade to a smart home! Every switch in my home has used the white neutral as a hot, even in three ways. The switch loop that Dustin explained is exactly my scenario. Please do a video showing some fixes. I have invested so much money in smart fixtures just to have them sitting around with no solution. Dustin you are the only one I trust to show me the proper way to remedy this Mess.
Great illustrations D. You always explain with clarity.
👏🏻 truly clearly understood, avoiding the 😵💫…everyone not in the know, should keep this video for reference not if, but when you stumble onto this in your work adventures.
In the UK we use the loop system as standard. Well, we did until recently when the need for a neutral at the switch became the norm. For the 3 way (we call it 2 way) it's possible to connect the constant and switched lives to the two switched terminals of one switch and then run a 3 core (+earth) cable directly from that switch to the other switch with one conductor connecting the two commons together and the other two connecting to a switched terminal each in either switch.
Sleaving must be used to reidentify conductors but cable with two browns (live/live) is common.
Man I use you back early years as a electrician in THE 70'S The first time I ran into a 3 way switch loop I was working on the house that was wire in knob and tubing long story short I figure out what going on You did good job explaining how a 3 way switch loop works Yes in today their many historical home that still wire in knob and tubbing
Great video! Thank you for your time and energy. I love your style and appreciate your delivery.
I have a special situation 😊 maybe you can help.
I’m in an old duplex with old wiring. They converted it from fuses to a breaker panel (hybrid)
Any way….. 2 lighted single pole switches one at the top of the stairs one at the bottom to control the hallway light.
There are only two wires, white and black. How do i get 3 way function out of this horrific setup?
I haven’t attempted to locate the hot supply yet. I’m willing to bet it’s coming in from the ceiling as described in the video.
I hate how they ran electrical back then
Our 1964 home in Georia has 3 way switch loops. Thank you!!
I've got several 3-way switch loops on my property (1985 house and out buildings). As I understand it, these don't meet code for new work because they don't provide a neutral for a smart switch. And that's exactly what I want to do, but without that neutral (or really violating code by using the ground as neutral for the smart switch :) ), I can't replace them. And to make matters worse, these are in areas that aren't accessible unless I start cutting holes in the ceiling.
You seldom have to bring such things up to present codes unless performing major renovations. Hopefully you still can purchase devices that utilize the ground wire for probably less then a milliamp of power. We were told at an IAEI continuing education class that one of the reasons for requiring a white grounded conductor ( no such thing in NEC anymore as a neutral ) was that in cases where people had a lot of them feed from a GFCI the slight imbalance between the hot black conductor & the white wire would exceed the 4 to 6 milliamps needed to trip a GFCI. If switches are in open basements or in conduit then a white wire is not necessary because it's easy to install one in the future.
Outstanding content! Thank you so much. You just saved me from wasting hours of guessing a wiring in an old house.
Ty for this. So informative, I’m gonna show this to my workers
I love how you explained all this, but I would love for you to blow everyone's minds and diagram out a FOUR-WAY switch for when someone wants three, four, five, ten switches for one light!
I'm not sure what the NEC says on the subject, but in the Canadian Electrical Code it says if you use "premanufactured cables" (NMD, BX, whatever) for switch loops, you have to use white as your "unswitched conductor" (aka, hot) and black as your switch leg. Also, in 2018 it was added that any switch for lights had to have a neutral present in the box (even if it's not being used, it's for if somebody wants to add a dimmer later that requires a neutral), so now you have to use 3-conductor instead of 2 for switch loops. I haven't seen or heard of a 3-way switch loop so far yet in my short career in electrical, but it's good knowledge to have for sure. I love these theory videos and learn a lot from them, thanks Dustin!
When working in older homes with fiber insulated wires and plastered walls these switch loops are very common. Many original fixtures only had a switch on the device itself. Lucky to see a actual wall switch to have been added at all over the course of their many renovations.
I'd be interested in knowing how you would install "smart" or "IR Motion" 3 way switches in this the 3 way switch loop scenario. Most of the smart or motion switches on the market require a neutral wire which doesn't exist in the switch box. I discovered this, much to my dismay when installing smart switches in a home I purchased which was built back in the 80's.
Excellent video as per usual. I started watching you when I embarked on this journey to update my new home. You are an great resource.
in the 3 way switch loop scenario shown, you would reconnect the loop wiring - each 3 wire loop wire would revert to hot, neutral, switched. then each motion sensor switch would be hooked up like a single pole, and the both red (switched) leads would connect to the light. best to have a contactor model of motion sensing switch for that, rather than solid state, since some solid state switches don't respond well to a backfeed.
Im totally gonna look and see if its already a thing, but while i have it fresh in my brain i was looking for a more detailed video on the differences between transfer switch and interlock. again if youve already made then thank you in advance! good vids brother cant wait for the next
Thank you. Best explanation of a 3 way switch ever. I think I finally get it.
I have dealt with many switch loops and 3-way switch loops, but never knew what they were called. Now I know.
Great content, downside is if you want “lighted” switches, or if you want to replace them with “automation” computer controlled switches. But again great style and presentation of content.
I did a 3 way loop on my house, when I built it. The main reason I did that was because the wiring was getting pretty busy in the walls. Took a little head scratching to figure it out, since I have never done one of those before but it worked out great.
Very informative. As a friend once said to me " its very intuitive when you know how" 😀
I so needed this video re-wiring my 1953 house and was having a hard time wrapping my brain around things not being in switch boxes
On the switch loops, i see the white being tied to the hot more frequently and the black being used as the switch leg.
Do you have a video, or diagram, of how I would hook up a switch leg when there are wires in the box that are also going to outlets? Then I have another wire that is going to another light that I would like to be able to control with the same switch, but there are also wires in that box running to outlets.
Great demo ... What brand is the white board ? And where to get one ... Thx ...
Utah small 50s-60s homes with basements, with about 1600-2000sf total, used switch loops, running first to the single light box, then separate wires, one to the four receptacles, and one to the light switch. For small 11ftx11ft rooms with one ceiling light this makes sense in order to isolate each room to one circuit. I completely re-wired the house in order to add a bigger service panel, get a main circuit breaker, add ground wires, and add more circuits. The tight layout of the house and all the load bearing walls made the most sense to keep most of the rooms the same size. It also seemed to make sense to keep the circuits in this loop to isolate each room to one circuit. The two larger rooms and kitchen were wired conventionally. Not everyone has a fancy new large home 3000sf+ and 1960 isn't that old. I kind of chuckle thinking that code (and electrician advertsising carring most about taking your money) makes it sound as if an original 1960s home will burn up or kill you at any moment and that the older fabric insulated NM copper wire is surely rotted, leaking, and arcing. All of mine was was just fine, likely less of an issue in Utah's dry climate.
Excellent video as usual. Succinct and clear. It seems like one way to identify a 3-way switch loop in cases of confusion would be that there's two cables coming out of the light box, right? Two sets of 15-2. You could check it from above or pull it out of the ceiling and check.
Actually it would be two sets of 14/3. But, in today's code, due to occupancy sensing devices, you can't assume seeing a 14/3 means 3 way switches.
@@NickFrom1228 in this case, when there is a single pole switch loop done to meet Code, the white in the 14/3 will be tied to the neutral in the light box, capped off in the switch box, the black is the hot and the red is the leg. I've used this method in remodels, to add a switch to a pull chain fixture. In new construction I always wire the incoming power to the switch box, makes troubleshooting easier if there's a problem later on, saves from having to get a ladder, even if it means using a little more wire.
@@Sparky-ww5re Makes sense.
@@NickFrom1228 Right, my mistake. But seeing *two* 14-3 from the light would mean 3-way switch loop, right?
@@Bapuji42 Probably, but I don't want to say this is the only reason you would see it. There is probably some scenario out there where you would see this but I can't think of any offhand.
Thanks for a clear explanation of this!
I watched 8 minutes of this video before I realized you're talking about what we call cold switching. 😆
The more you know 🤙
i call it a reverse switch leg/3way
Thank YOU 👍👍👍👍 This is an excellent lesson 👏👏👏👏
THANK YOU very much for this video!
I managed to reverse engineer / forensically deconstruct this exact setup in my PacNW house that the original long time owner had rednecked his electrical over several decades and 5+ additions and renovations.
It's nice to see how it was originally intended to have been installed; it explains why his janky/kludgy repairs were done that way.
I may not have even been a certified electrician but I'm not afraid of an NEC code book and have been bringing circuits up to modern safety standards as I find his installed fire hazards.
Except the THREE breaker box situation with a "main" breaker panel and two mini breaker panels. The first mini breaker box was fully Zinsco parts but only the left side was used ... so they covered the punched out right with duck taped cardboard.
Oh: it also may or may not have been wired in on the street side of the meter.
I hired a professional (the 2nd most expensive and well recommended) to make this problem safe and legal. I can deal with science but not the law.
The original owner just seemed to add copper until the lights came on.
I have a situation where I have to do something similar with 277v ceiling lights. Thank you for making this seem so clear !
You are a VERY good instructor.
Thanks for you video. I have an issue that might be "switch loop." the dining room Chandelier was the old type, no neutral, just look like brown extention cord wiring. It was be control with a smart dimmer switch. When I look in the ceiling box, there was three wires, black, white and ground. On the old light fixture, the wire that was connected to the white in the ceiling from the old fixture had black tape on it. Before this video, I tried hooking up the new fixture like you normally would but as you may already know, that did not go well. I blew 4 smart switches from tplink before I gave up. What I don't see that your video describes is an additional set of wires in the ceiling. What do I do? Also, I noticed when testing what was the power coming from any of my outlets was above 240. I know that's not normal so I disconnected the wires from the switch and turned of the breaker until further notice.
A few years back we came across a five way switch loop, that a renter had replaced one of the switches in. I took a full day to figure it out and get it wired so it worked. We had to find an easel with a 3X4-foot pad of paper on it, set it in the room we were trying to figure out, and diagram the whole mess before we figured it out.
Drawing out a schematic really helps put things into perspective. Did you disconnect all the switches and the light to track down what went where?
As an American living in the UK working as an electrical design engineer(I'm the guy you hate haha) , switch lives is mostly what I'd used here. However I tend to work on large commercial projects and they tend to use ELV switching instead. Great videos!
As a future Electrician Helper ... I thank you for this video.
Is it feasible to do a 3 way switch loop with 2 wire cable from the ceiling box to each switch box.. and 3 wire cable ran between each of the wall switch boxes? Again, two, two wire cables from the ceiling box where the hot enters, to two boxes where 3 wire cable connects between the two boxes. Thoughts?
Thanks for this. My house was built in the 60's when they sent copper to Vietnam and put aluminum wire in houses. I wanted to put in a socket, assuming I could get a hot wire from the switch. The result was lights flickering when using the socket. Now I know It was the hot just run down from the ceiling powering the vacuum through the lightbulb.
Great video was having a hard time trying to understand how to hook up a 3 way WIFI switch with no nutral wire in both boxs, THANKS TO THIS VIDEO I now know whats in my two 3 way box switches for the basement lights ,
back in the day someone used two 14/3 wires in each switch box the colours are black, red, white, whey used red & white as travlers, the 14/2 power wires are in a junction box in the closet ceiling, the hot black is together with the 14/3 black on the upstairs switch, the black wire in the basment switch box is the load wire to the light wire, and the 14/2 white nutral wire in the junction box is together with the white wire for the lights .
Hope this makes any sence, unfortunetly i was not able to hook up the 3 way WIFI switch because of no nutral wire, i did hook up a Leviton DSL06 dimmer switch, But the switch has a low humming sound coming from it, lights turn on and off, and dimmer works fine, Just dont know why the low humming from switch ?
Last year I came across an interesting loop. I didn't know it was a loop at the time. Situation: hallway, three single switches (one on each end and one in the middle). Someone decided to upgrade the switches and instead of replacing the old yellow 3-way switches with new white ones, they installed 3 single-gang switches. I had conductors on the grounds!!. This mess had wires connected together that shouldn't have been and some capped off and yet no breakers were tripping. So I removed the switches, pulled all the wires out and identified them with continuity checks. So it was actually a 4-way loop. It took a couple of days to wrap my head around it, since the power came in from the light fixture in the middle of the hallway but I finally got it all working. Man, what a learning opportunity!!!
Amazing video as usual! Thank you
I love how you explain your video but I'm from UK and we are blue for N Red for L and copper for E
Very interesting how different places have different ideas.
I'm in the UK, the switch loop as described here is how is how it's always (rare exceptions) done, a ring from the fusebox to the first light then looped to next then the next etc until the last goes back to the fusebox. At each light a 2 core cable (twin and earth) goes down to a switch with the red (live or hot) to the common connection and the black (neutral) to the sw1 connection and marked with red tape, at the light box/chamber the red is connected to live incoming ring and the black with red tape is connected to the fitting live connection.
All neutrals are bunched together.
What is being called 3 way on the video is what we call 2 way and instead of having wires from the light to each switch we have 1 to the first sw then from there a 3 core cable (3 core and earth) goes to the second switch.
Hard to describe but think of it as like the 3 way switch loop here but missing out the light fitting.
3 way switching here is where you has as described above but with an intermediate switch between switch 1 and switch 2, think of a crossover switch.
You can put in as many intermediate switches as you want and just call it by how many switches are there eg 5 way 6 way.....
To surmise you have a ring of light fittings, each fitting has 1 cable to a switch, then if its 2 way you just run a cable from the switch to the next switch and so on, Radials you could describe them as.
Perfect explanation! Great video!
I wonder if THIS particular video might be served with a follow-up video where a set of physical light switches and a light are used, with the appropriate ROMEX is used between all of them? That might clarify the illustrations.
In the 3-way, what purpose does the ground on the leg side switch serve (since there's no ground connection from leg to hot side)? Could you just use 12/2 for the leg side run?
same as everyone.. thanks. I knew the mechanics of them but didn't get the understanding until this video. I watched another a while back when you guys taught me that there is code for the number of wires that you can have in a box. wouldn't you break that code since normal 3-ways at the box only 3 conductors: hot, common and ground. with the 3-way switch loop you would now have 11 if you include the ground for all of them:
source: common, ground, hot
for each leg:(hot, common, traveler, ground)x2
This is off subject. Do you have a video on how to build a proper pull head for larger wire like 3/0. I need some direction for easier pulls for larger wire.
Great video, such an educational channel
Hey! Great video. However I think I have a switch loop in a new basement remodel where the whites were reidentified. The problem though is that the wires the electrician painted as hot weren’t being used as a common. The hot wire in one leg of this 3 way circuit was the black traveler. I’m totally confused by this. We are trying to setup Kasa smart switches and it’s been such a headache. Any advice would be appreciated.
Thanks for another great video. Whenever I am taught something I need to know how it all works and why. That is how I easily remember the lesson. This is exactly what you do so well. Could you do a video explaining how some devices require no neutral, yet obviously get voltage to operate their internal electronics? Like exhaust fan timer and smart dimmer switches requiring no neutral connection to operate. I have always thought I should only use these types of devices requiring neutrals, even if I have to repurpose a wire or run a new one to the box. I have a lot of smart dimmer switches installed but only use the version requiring a neutral.
some of those devices used to run their "neutral" through the fixture they controlled, which worked okay with incandescent lights, but can cause ghosting in LED bulbs, or degraded device function. the next generation uses the grounding conductor for their neutral, which, of course, can cause conflict with GFCI or AFCI protection. most of those will have a separate neutral and ground conductor, so they can be combined on the ground if necessary, but are best connected to the neutral.