Polarity: It’s All or Nothing!

Hey, Dirt Farmer Jay here from DirtFarmerJay.com. Recently, we put out a video called The Safe Way to Rewire a Table Lamp. And in that video, we're showing you that polarity really does matter. But it doesn't only matter at the lamp or up here. It matters elsewhere in the circuit, like the plug-in and the wall receptacle and so forth. I'm going to give you some insights you're going to find to be valuable and to keep you safe. Stay tuned. I'd like once again to give credit to the original video. Robert Ibbotson, a friend of mine that I met recently on a trip back to Iowa, gave us the idea for the first video. Another fellow viewer family member wrote in, Rodney McGee. Rodney McGee interacts with us on an ongoing basis. And so, Rodney, thank you for this great observation. He said, polarity should also be observed if the problem is on the opposite end of the lamp cord, right here with this. That's the plug. When replacing the molded plug, this is a molded plug right there. It's molded into this, has the original label. When replacing the molded plug with an aftermarket replacement plug, the wider terminal is the neutral and the narrow terminal is the live or hot terminal. Rodney, you are absolutely correct. And I want to give credit to him for what we're going to talk about right here and why it's important to know this. So what we have here are some common electrical devices. We have a common receptacle that is usually used in the wall. Here's a light switch that is just the run of the mill. All this is a little bit heavier duty one. You can see by the depth of the body and so forth. Here's an aftermarket plug and here's a multiplier tap. Now, what I want to point out here, we mentioned that you've got to use polarity correctly. That is the hot side of a circuit, usually denoted by a black wire, is what gets switched on and off first. And you don't let that run through a device and then put the switch on the other side. You always want to kill power to a device or to a circuit first off or to turn it on and off that way. Now, this way of wiring is not only observed in appliances and things like this, but also on the plug-in. And if you'll notice on this plug-in, there is a difference in the blade width. When a device really is important that polarity be observed, you're going to find this type of plug. Now, you can look at this little shot that I took recently at Home Depot and see other plugs that don't have this observed. The reason is that it's not attached to a device that matters one way or another. But for many, this is the case. Now, what have you got here? What Rodney just mentioned is that the narrow is always going to be the hot or denoted by the black wire side, and this is going to be the neutral side. So, you'll notice when you go to plug this in to a standard wall receptacle that you can only plug it in one way. If I try to do it this way and reverse the polarity, it's not going to let you do it. If I rotate it 180, now all of a sudden I can plug that in there and polarity is correctly maintained. Now, how do I know that that's the right thing? Well, let's look at the device itself. If you'll notice on the side, there's sets of terminal screws right here. On this side, they're brass colored, and on that side, the screws are silver colored. Brass, it always denotes the hot side. I use the little memory cue, black to brass, and I use white to silver or white to white. So, black over here is going to be the hot side, and you'll notice that side is feeding that narrow prong. On this side here, where it's silver, the neutral, it is connected to the wider prongs. Therefore, when this is wired observing this wiring convention, polarity is correctly maintained in this device, and you'll find this all the way back to your circuit panel and ultimately all the way back to the main grid itself. Polarity is maintained. Now, here's something else to note. Here's another common device, and notice that on the switch, that there is only gold terminals. Why? To correctly utilize these, you're only going to put this on the hot. You're going to interrupt the circuit by starting the circuit at the top or the bottom and out the other side, and then either the circuit is turned on and off before the electricity flows or doesn't flow onto whatever it's loaded onto, whether it's a circuit, some kind of light, a switched receptacle, or so forth. So, that is how that is maintained. All right, let's use another example. In this case, I'm actually holding a little tester that will show you how this works in a moment, but for right now, I'm just using the end of this to illustrate. Notice that the blades are essentially the same width. There is no polarity difference being shown on this. So, how do you make sure that this is inserted in the plug correctly or any other kind of plugs that are like this? Well, simply the ground rod that's sticking out of it only allows you to insert it in the receptacle the correct way. You can't do that. You can only put it this way, and therefore, polarity is going to be maintained. So, that's another way that that's addressed. While we've got this in my hands, let's go ahead and talk about what is this little device. You can buy this at any of the big box stores in their electrical section, and this is a little polarity tester, and you'll see on there there's a little legend that tells you whether or not the circuit or the outlet is wired correctly. And so, when I plug in this into an outlet, depending on what happens, if you get a central just yellow light right here, that means the ground isn't connected. If I get only that light, that means that the neutral isn't correctly wired or it's open, and you're only getting the hot side of the circuit. If you end up with it all lit or nothing happening, it means you got an open hot, meaning there is no energy at all flowing into the outlet. Next one, if you get red showing up over here and yellow showing up there, then that means you have the hot and the ground reversed, meaning that the ground is energized. Not good. And then, as you come down here, the next one is, if you have these two lights lit up, you have the hot and the neutral reversed, meaning the neutral, the polarity is incorrect. You've got hot coming through the neutral and nothing happening on the other side of what would usually be the hot. What's the correct one? When these two light up on the side, it means that polarity is correct and it is grounded correctly. Well, we're going to go ahead and test this and show you what it looks like when you plug it into a real outlet. All right, so we're going to go ahead and test it right here. We're plugging it in. Let's see what happens. Well, look at that. Notice that we have two lights. That's indicating correct. We've hot where it should be, neutral where it should be, and ground where it should be. And this little tester will let you know whether or not receptacles are themselves correctly wired in your home. Again, polarity matters because you want to make sure you're doing the same thing throughout, uniformity, so everybody's kept safe, and anybody that opens the circuit to service it later on has the power in the right place. This is just good courtesy and great safety. If you have a great idea like this that you'd like to pass on to your fellow viewers, why don't you send it to us in the comments below? And if we use it, we'll call you out just like we did our friends Robert and Rodney. Thank you for watching the video today. If you found it to be helpful, why don't you like it, and better yet, subscribe to our channel, and make sure you ring the bell. That way you'll instantaneously know when we publish a video, which is approximately every Friday. Hey, thanks for watching today. Be safe out there, and remember, polarity matters.