Explain a Switch Loop

today I'm going to explain to you the difference between a switch loop and a standard wiring method hi my name is Craig Michoud and I am the electrical instructor so what's the switch loop well how many times have you gone to replace the switch and see that you have a black wire and a white wire on your single pole switch well this is common and typical practice of older homes now the code book states that we're not allowed to use switch loops anymore that we're allowed to we have to have a neutral in every box yo this new technology that we have now is smart houses and whatnot this is what we're going to need we need the neutrals so this method is actually going out but the problem is is if you go to do a service call in an older dwelling or you go to somebody's house and you need to do a little bit of work and you pull out a single-pole switch thinking you're gonna tap power off of it you may not be able to if you have a black and a white wire on your switch that means you're using a switch loop what does that mean well let me explain it to you using blue as our neutral and we're using black as our ha our feed to wire ok so what I'm explaining this please understand that I'm talking about romex or some type of cable BX cable whatever it may be okay so I have a 2 wire I have we are feeding at the light fixture so by feeding at the lights that they'll at the light fixture we're gonna run a 2 wire from the light fixture down to a switch now so how does it get lighter simple the feed neutral goes right to the lamp and the hot wire coming in splices to the white wire going down to the switch the black wire going to the switch is going to go back and it's going to tie the lamp but this is how you can always remember it feet down on the white and back on the black in a switch loop this is how it works now I had this question on my journeyman says they asked and I've seen students number of times do it opposite and end up with two white wires at their light and guess what that's wrong you can't use a white wire as a switch leg but you can use a black wire as a switch leg okay so you have to keep that in mind now what I need you to remember is we always have to reify our white wires so as you can see in my diagram here I actually identified it at the switch so what we need to remember is we need to feed down on the white and back on the black make sure you identify that white wire now will you go into a home and not see that white wire identified you will okay net every electrician does that most electricians like myself will pull a switch out like this and they'll see the black and the white while see the black and the white wire and already know that I have a switch loop okay so remember just because you see it and it's not identified doesn't mean that that's not what it is if you go to a junction box and you see a white wire connected to a bunch of black wires guess what you have a switch loop okay so a switch loop is very basic let me show you on the board and explain it a little bit better okay so here I have two lights and two single pole switches I'm going to show you the standard way we wire a switch and then I'm going to show you the way we wire a switch loop so here here we have two black wires our feed wire which is connected to our wire nut through a pigtail we have our whites are all spliced together and we have our switch leg which is actually going to our single pole switch okay so what happens here is when I turn this switch on this light comes on when I turn it off it goes off now this is a standard way I've done a video in this already on how to wire a single pole switch if you're not a hundred percent sure on how to do it please go back and watch that video so now I'm going to show you what our switch loop is about okay so at our light fixture we have a wire coming in that goes to the top and that's going to be our feed then we have another wire coming in and it is going to our switch now let's start here single pole switch I have the two wires so I have my white wire is reaiiy denta fied because i'm using it as a hot conductor now and my switch leg so my switch leg and my feed are on my single pole switch when we come back up here coming in and then we have our wire going from our two wire switch loop okay so the feed wire which is the black will go to the white the white will go exactly and straight to the light fixture okay we're gonna do the same thing we're gonna re identify the black wire or the white wire we're gonna re identify the white wire we're gonna splice that together we're gonna bury that okay that's gonna end up going right into our junction box okay that doesn't get connected anything our black wire from our switch leg from our two wire loop is gonna go rake to the light fixture okay now when this is all done all we have to do is flip the switch and the light comes on flip the switch again and the light goes off how you wire a two wire switch loop it's very basic and you will see this but this helped you understand what a switch loop is actually all about Sonny's switch leg it's a switch loop okay so if this helped do me a favor to give me a thumbs up if you have to subscribe please subscribe and just remember that if you open up a single pole switch and you have a black wire and a white wire on your single pole switch you have a switch loop which means the next step for you you go check the light fixture have a great day and be safe

Channel: Craig Michaud- Electrical Instructor

Views: 22,441

Keywords: craig michaud, craig, switches, switch loop, 2 wire loop, electrical instructor, electrician apprenticeship, residential electrical wiring, residential electrician

Id: OnUZiYXb3nI

Length: 7min 28sec (448 seconds)

Published: Thu Jul 19 2018