EVALUATING YOUR CIRCUIT WITH ONE HEATER ELEMENT
Welcome back. We're so glad you're with us today. Today's topic is going to be evaluating our system to make sure that we have the appropriate power, the appropriate equipment, and we're actually safe, we don't want to cause any problems. So please bear with me because this is a really simple process, but it's very, misunderstood.
We need to get the whiteboard, because we're going to do a little bit of math as you've read on the other discussions. Bear with me, it's not that difficult and believe it or not, it's relatively simple. So you can use this as the applicability of what you're going to pick up today can be used to the shop at the house at the great all over the place.
Let's talk about our heater elements, heater elements that we use in our heating process now whatever that process may be, and more than likely it was probably a still you can use. Hot Water Heaters have heater elements and that's what makes your hot water hot. And that's the electric type. So we've got the 2120 volt heater element. They also come in 240 volt heater elements, and that's one here. This is a 3500 watt.
Now what's the difference? I've got one out to warn that a 20 volt heater element has two screws on it. So you'd put a hot lead in a neutrally and that'll make that sucker work. That's all it is, one hot one neutron was not polarity specific. You've got two screws, you got two wires. And then you got the ground. On the 240 volt, you've got two screws in with 240 volts. You also have two wires, which both of them are hot.
So you put one here, one there and then you've got the ground. So there you go. You see you can wire up 120 or 240 volt elements already. It's that simple.
Here are some of the things you cannot wire a 120 volt element to 240 volts. If you do, you're gonna have a problem, it ain't gonna work, you're gonna probably blow it, it'll break, it'll burn, it ain't gonna work. And also people don't dry fire. And what we mean by dry fire is, all wired up and then turn them on to see if they're going to work. Make sure they're inside, you're still already or inside some liquid so that it's got something to dissipate the heat form because it gets hot pretty quick and it gets really hot. The 240 volt element can be wired with 120 volts, or 240 volts. And there are some instances where you may consider that and as we go through the math, you'll see what I'm talking about because you may want to try to match in mix.
Some of your elements in order to stay within a certain range so that you don't overload your circuit. The 3500 watt element, if it's wired at 120 volts, you lose when the voltage goes down, the power goes down. It's reminiscent of if you've ever heard of a brownout how your lights will be dim because you just there's just no voltage going through the system.
In some states they have that happen. The same thing happens with a heater element. So, remember this when you wire 120 volts to a 240 volt element, you lose 75% of the power, so this 3500 watt element now becomes an 875 watt element. Good to know if this was a 5500 watt element, then you are at 120 volts, it would be 1300 and 75 watts.
Why don't we say watch what watts are the power and what we know about electricity. You know what, let's go straight to the whiteboard. So don't waste any more of your time.
Here's what we know about electricity. There are four values of electricity that we are very accustomed to, and we know or we can find out and that is P for power. And that's normally indicated by a W for watts. We have E, which is an electromotive force, known as volts. I, which is current, known as amperage and are which is resistance. So, if we change these just because it makes it easier to explain, and easy to understand, we've actually got WV a r. watts volts amps resistance. The point is that if you know any of these, you can figure out the other ones. And that's important to us because we need to understand what the requirement is going to be.
Let me explain this, your household system. If you look inside your fuse box, you've got this big box. You've got all these breakers. Or in some cases, you may have screw instructions. But you've got all these breakers with a switch on and the switches either on or off. And when the breaker trips, the switch it trips off and you go back or turn it back on.
Once you've unplugged something, but you've turned it back on, that indicates that you've exceeded the value of each one of these breakers, whichever one blue. Now they're normally they're normally listed in your box, you'll see it's written right on there. They're either 15 or 20 amp 30 amp, and there's also potential of a 50 amp.
Some of your stoves will run on 50 amps, it all depends on what the power drawl is in the house and what appliances you have. So you have to match the appliance to the circuit so that you don't blow a fuse or create an unsafe environment where you burn up the wires inside the wall and burn down the house. We don't want that to happen either.
Remember when we talked about this once before,if you push enough current through a conductor, and you're pushing more current and that conductor can handle the byproduct is heat. If you push enough current through there, you'll burn the insulation on the wire. You could burn the conductor in half, and now you've got a fire hazard and we want to avoid that. Let's talk about Europe real quick too because Europe has 200 and 40 volts standard, and we have 120 volts standard, but they're wired the same way we're wired. So it's a single phase, meaning you have a hot and you have a neutral. And in your hot neutral is 120 volts and a neutral.
We know that electricity AC runs back and forth. Let's just say we have a hot hundred 20 volt, and we have a neutral, which is a return. That's just for sake of argument. I know there's a whole lot more into that, but we don't need to go down that road. Now in Europe, they have 240 volts and a neutral. It's the same thing. It's single phase, but they just have 240 volts of neutral. So you can wire this in Europe the same way.
In the US. Our standard requirement for household wiring is 12 gauge wire. It's called 12 A wg it's 12 American wire gauge and a 12 wg wire can handle 25 amps. We've got a circuit with wires that run out of here and they go to receptacles throughout the home. This circuit is normally going to be connected to a 20 amp circuit. And in some cases, they could be on a 15 amp circuit. It just means if you're using more than 15 amps that circuit is going to blow, and you have to start removing things and or isolate that circuit. But what this means is that this wire is capable of handling 25 amps, although it's only 20 amp circuit.
Why is that? Well, we don't want to put a 20 amp wire or a 20 amp circuit breaker when we get to 20 amps, there's a whole lot that's been going on a whole lot of heats been building up in order to trip that circuit. So we put a 25 amp capability capable wire on a 20 amp circuit so that it doesn't reach its maximum threshold and the circuit can break.
Does that make sense? It's rather simple and straightforward. It's sort of like being safe and then safer than safe. And that's why most homes are wired with a 20 amp circuit. You also want 30 amp circuits. And a 30 amp circuit will normally be on a 10 a wg wire because a 10 amp wire a 10. A wg wire can hold 35 amps. So that's where you can carry.
All your system is rated for 20 amps or 25 amps. But you really run it through a 20 amp circuit so you are safe. Here's where we need to be evaluating what we're doing. We need to evaluate.
Are we in danger of exceeding this value? And we can do that relatively simply. We know that this element is 3500 watts. And we know that this element is 2000 watts. But what we don't know is the resistance of that. Because remember we had w watts, V volts, amps and our resistance, so there we've got this uglies manual. What we do know is we do know that volts squared divided by power is going to equal our resistance. We want to know resistance first, because we're trying to find out amps. We want to know what the amps are.
There's one simple formula for that too. But this makes it a whole lot easier for us to explain. We want to know how many amps are going through our circuit and what is the requirement from that element.
What is the resistance of this element in that hundred and 20 volt circuit? So that we can determine what the AMP requirement is in order for that to work at 100% efficiency or when it's all in 100% of the time. If we did take this, we know we have 125 squared divided by and we're going to use the 2000 watt heater element or 120 volts 2000 volts of watts.
Go our calculator is really easy as 120 squared divided by 2000 equals 7.2 7.2 7.2 ohms of resistance.
Now that we know what the ohms are, what the resistance is of this hero element, we can easily figure out what is the amperage draw and what is a maximum amperage draw that we have to be concerned about. In order to figure that out the formula for that really easy is flip there you go volts divided by resistance equals amps.
So we have 120 volts divided by 7.2 ohms equals 16.6 amps. If we're on 100 if we're only 120 volt 20 amp circuit, and we run a 2000 watt heater element on that circuit, we're only drawn at max. We're only going to draw 16.6 amps so we are safe. Now remember that wiring we can handle 25 amps. The circuit can handle 20 amps before it trips because that's being safer. Safe in our requirement draw is only going to be 16.6 amps.
So, we went watts volts amps resistance, and then we had you know the voltage squared divided by w or P, the power wattage. So that settles that. Now you know that a 2000 watt heater element or 120 volts, pull 16.6 amps So, or a 20 amp circuit you are safe.