• Oct 28, 2020
  • by Moonshiner

We got four wires for 240 volts, or we can use three wires for 240 volts. Or we can use a combination of the four wires 420 volts, or the three wires for 120 volts. If you don't follow some basic simple rules this could kill you. I have to be perfectly honest. So none of us want to die. Remember the 120 volts you got a black or white, a black and a green, the green is ground, the white and the black is 120 volts, a hot and a neutral. 

On the 240 volts, four-wire you have, 240 volts you have a hot red, a hot black, both of them 120 volts each out of phase, a white neutral, and a ground. So you get 240 volts by using the two wires as your hot wires. You got the green for the ground, but they don't require a neutral they equal 240 volts. They’re own neutral. If you use a red wire and a white wire, you get 120 volts. You use black wire and a white wire you'll get 120 volts. We already know this when you get 120 volts By using a white and a black, but you could also use it as a 240 volt since 240 volts doesn't need its own ground or doesn't need its own neutral.


So you can hook where the red one would go and the black since it doesn't need a neutral, you're using the white wire as a red wire and you've got 240 volts that will permit us to wire either the 1500 watt or 2000 watt hundred and 20 volts or the 3500 watts 240 volts. We can actually do both. So we get a full understanding. I've got set up as a sub-panel. If it was a complete subpanel, there would be an additional bar that I would place and that's a separate purchase. 

It looks just like one of a bar with a bunch of places to put wires, and that's the ground wires. You'd mount that on the side or you'd mount it on the bottom. Because just a bar you screw right into the box when you hook your ground wires to. If it was the main log Center, the first one after the pole in the house well actually bond the box. It could use one side as the ground the other side as a neutral. But if it's a solid panel, you have to have a separate ground. 


That's just to make sure I cover all my bases with the electricians because it is very important. The only time that you hook a ground is a neutral together, the main import into the house that's your main load system. After that, if you're using a subpanel, you'll always need to have that separate ground busbar. This will look like 100 amp breaker and this hundred amp breaker energizes the two bars you'll have the red wire will hook to lug the black wire then the neutral wire will hook to load your ground wire will go to the ground busbar.

So what we have now is we have 120 volts in 120 volts that mean each one of the bars is going to be energized but maintained separately at 120 volts. So if you hooked a multimeter to the bar and that lug and just tested it, that would be red and the white. You get 120 volts if you put your money the meter point and on the black one and on the white one, we get 120 volts. Now the same is true on the on-ground busbar if you went from the black to the ground, you'd get 120 volts. If you go from the red side to the ground you would get 120 volts that's because of the difference between the two. What's interesting is if you take both of the leads and put on one bar and put it on the other bar. The limit of what you can run through will be controlled by 100 amp breakers. 


So this is known as a 100 amp sub panel. You can have 125 and a 200 it may come in various different degrees of how much amperage they'll handle. Now all of that's controlled by circuit breakers. There's a one made my homemade by squared you got made by GE they all work the same way. They look at different designs, it's all the basic same principle. Just make sure that your breakers match the type of box that you got, or else they won't fit. Known as a single breaker single pole breaker, it's tripped you have to wire on the bottom. 

The hot wire and the breaks will fit which means that I draw the power from the leg because I'm on the lug even though that breaker on the side of the box, it's drawing from the bar. I put in the lug so that means the breaker is going to pull 120 volts from the bar, the breaker will pull 120 volts from this bar. Your hot wire will work on 120 volts right now, you would hook the black wire on the side so you would hook that up first, make sure it's turned off then plug it in your white wire would go to the neutral bus. Anyone of the screws is altogether going to the same place then the green which is the ground would go to the green bus bar which could be wherever you placed it.

In the particular case, we have one that's drawing from the side and the other side. Remember we have both sides in order to get 240 volts. I had the breaker sitting, then I take my four wires and I hook a red which means I draw 120 volts, and the black one which is drawing 120 volts my white one to the neutral busbar, and my green one to the ground. What have I got? 120 volts. I've got it on two lines because they're all in the same phase. I got them all the same.

It was 120 volts in the face, red, black, white, green. So it's not that difficult to wire it yourself to find back a fault and figure out what went wrong. When I go across the black one in the ground, I get 120 volts. When I go from red to ground, I get 120 volts, you should be 240. What you do is you're using two circuits from the same and guess what, you're going to get 120 volts from each one. You're going to get 120 volts from each one. 

The only difference is that since you're using two bars, they add together to 240. In the other case, using the same bar, the best you can ever get 220 and they got a really nifty device. It's called the double pole. 


Now, it is a 30 amp breaker and the 30 amp breaker you'll notice has two connectors on the bottom has two screws for two wires. It's just like taking two of it sticking them together. That's all it is. No matter where you put it. It is always going to connect one side and the other side to the same breaker. 

So when you hook up, you read a black Light underground, you've got 240 volts that are 120 volts out of phase on each, you got 240 volts tall. Could you use the 120-volt circuit you certainly could add it's not advised only because if you Blue 120 volt circuit it’s going to shut both of them off that's why you have the single-pole breakers so that you’re primarily used for one item for like a 200 point like your range, or your air handler and your air conditioner or your heater and your furnace. 

A large item large appliance has a lot of drawing because it's a 30 and it's easy to put together. Just it's so simplistic, but still very dangerous. In every case, always make sure the main power is shut off. If the sub-panel will back to the main breaker and shut the entire box off because you shut it off, there's still power. If you shut the main breaker off, you can do anything you want!

But remember please test it first. Just for safety!