240 V vs 120 V EXPLAINED
Welcome. We're glad to have you back with us again. Today, we're going to do a discussion on this load center that you'll find in your home or in the shop. If it's a sub panel, it will describe more about that. But I need to get back to some basics. So we can understand.
First of all, if you are unfamiliar with or you are shaky about messing with electricity, gas, just turn this off and go to something else. It's not going to help you unless you're just curious. But this is for those who want to delve into it because it is safe. But be cautious because a big mistake could kill you. We have residential electricity. It is for the US and Canada only the European Union and some other countries have a different way of wiring things. But in the end, it all kind of makes sense.
We run 60 hertz, which is 60 cycles. So 60 times a second, something's happening. Just understand that in 240 volts or 120 volts, we've got two diagrams here and that's just a demonstration of the two types of wire that I use around here. This is a four wire. So you'll have a black, a white or red and a green. And then we have three wires. Both of these are 12 gauge, they'll carry a pretty good substantial amperage load, and a white, a green and a black.
There is such a thing as a 240 volt, three wire load. And then there's a 240 volt for wire load and we're going to describe that so you'll understand the difference. Here's how we get 240 volts. Here's a sine wave, I did a hand drawn sine wave and you'll notice I've got a positive negative positive negative positive negative, that's 120 volts. at the same time I have a negative positive, negative positive, negative positive hundred and 20 volts, that's what's known as being 180 degrees out of phase. This is actually separate phases of an electrical sine wave.
The benefit of this first of all, as opposed to this one, which is only a positive, negative, positive, negative positive 60 times a second. This one is you get a little bit smoother action of constant power voltage. Plus, you can actually add these two peaks together to get to hundred percent. 40 volts, or in this case, you'll only get 120 volts. It's only 120 volts. So that's how that actually happens between the two now, and both of it can be used interchangeably. Let me explain that so that we make sure that we don't get too off track because we don't want to get too technical.
You got to read a black or white and green. Your red is hot, Black is hot, white is neutral. And green is ground. So here you got to read and a black.
Behold if you use the two wires, you'll have 240 volts. In this one you have a black, white and a green. This one is the black. So if you use the black and the white, you'll have a 120 volts, we all know the green is ground, in both cases green is ground. But if we had a black and a white on this wire, because this is a 12 gauge for wire if we use a black and white, we would have between these two 120 volts Okay, if we used just the red and the white, we would have 120 volts If we use the black and the red together is when we have 240 volts. Now why is that? Well that is because our appliances for instance, arrange your stove, your heater elements and the heating element inside the stove is normally 240 volts. But you got all this other stuff in there.
All the dials and trinkets and things that make it work that turn on controls. In the clock, well, they normally run off 120 volts, or you got some Transformers in here, this runs off 120 volts. So what you do is you'll tap the red and the black for your 240 volts. And you don't need a girl neutral wire for 240 volts to work, it has its own neutral. Whereas 120 volts, you need the neutral for a return. So you tap the red and the black, you get 240 volts. And then for the other instruments that are in there, you will use out of the black and white or red and white to tap only 120 volts. See how simple it is. Now for most of our 120 volt appliances, or devices, you use the black and the white, that gives you 120 volts and the ground. That's for safety.
This is a 240 volt free wire system. That's possible. Very, possible. So what we would do in that case, keep us in mind it has to be on this cycle, not this one. So you can use this wire over here. And since 240 volts does not require a neutral, you can put the black wire to the black, the white wire to where the red normally would have gone. And then the green to ground.
You have 240 volts between these two lines instead of 120. And that would be for appliances that as an example are some dryers out there. You got a three prong dryer that's hot and hot ground. You got a four prong dryer that's hot and neutral in the ground. It's probably because the buzzer works off of 120 volts. You have other appliances that will have only a partner integration And so that's a 240 volt three prong or three wire. Or most conventions nowadays have the four wire, but you'll still find them out there.
There's three wire 240 volt connections for 20 volt you can tell by motherboard or you're going to use a 240 volt. This way you can wire it safely and make it work. Because then 120 volt you'll have a hot neutral and a ground. So you'll have 120 volts going in and out. That's why it's 1500 watts 120 volts.
In this particular case, you've only got two screws on the bottom. So you put a heart and a heart.
So you'll have 120 volts going in one side and 120 volts going in the other side but they will be out of phase so that would be a total of 240 volts constant and it gets hotter. Ground wires for the appliance put that right on the plug where you can hook it, screw it right directly to your device. So that's why it's so important for us to do this safely and effectively, but we just have to understand now that we know how to do it?