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The US electrical system is not 120V

May 31, 2021
this video has had something like 17 false starts. I've gone down several rabbit holes trying to understand a lot of things and at one point I committed to making a completely different video because of that, but then I ran into a series of conceptual obstacles that I don't have the energy to tackle right now, so that we return to the simple scope of the first. Now I'm going to be honest, my main point with this video is to address a complaint I have about how the rest of the world seems to understand the

electrical

system

of the United States and, in general, North America, although it is true that we have designs terrible problems with barely adequate receptacles and that our kettles are slower than yours.
the us electrical system is not 120v
Here's a fact about us that I think will blow some fuses. There the US is a 240 volt country. I can hear many of you saying, but it is true that we have 240 volts in our

electrical

panels and at our disposal you will have heard about our obsession with air conditioning. Do you really think we are cooling our Gandhi McMansions? with a machine we just plug it into a regular outlet, no, and some of us have electric stoves, electric water heaters, clothes dryers, and even an electric vehicle charging now, we're not doing all those things on a measly 15 amps at 124 1800 watts, how are we?
the us electrical system is not 120v

More Interesting Facts About,

the us electrical system is not 120v...

As we do that, then let's take a trip to the other room where I have a US standard service panel that we could see here is a US standard service panel that we can see. It may be a little difficult to reach. I'm just kidding. I added that 60 Hertz hummed in the post, did they really appreciate that our service panels are some kind of disastrously loud thing? I bet some of you did it anyway. This building is a single family home which is important because of one small thing which I will mention later in this small What works on the side is a doorbell transformer, don't pay attention to it and also any of the wires which may be a little less small that others are your doing, but again, it's not important, now inside we will find a main circuit breaker on the top and a bunch of, in fact, for many people, an absurd number of circuit breakers feeding individual circuits, but there is still room for two more, the main breaker is a 200 amp breaker.
the us electrical system is not 120v
This house, like many and almost all houses built in the last few decades, has 200 amp service now you might be thinking that it is 200 amps at 124 24 kilowatts at our disposal here, but no, it is 200 amps at 240 volts, so That, in fact, many homes have 48 kilowatts to cover a hundred-ampere service is still quite common, but 24 is still enough. Kilowatts are sufficient for smaller homes, especially since natural gas or other types of heating fuel combustion spaces is still quite common in these parts. Now take a look at these circuit breakers and you will find that they have their rating printed on their switches and you can also see that some of them are weird, they take up two spaces for some reason, well those are 240 volt circuits, this one goes to a dryer clothes, this is also an air conditioner, etc., but why aren't two spaces that seem a little strange?
the us electrical system is not 120v
Well, the reason it takes up two spaces has to do with the weird way we get 240 volts. You see, our power transformers that power our homes produce 120 volts, but twice, yes, it's strange, but first a quick reminder of what transformers are. More than it seems, the reason we use AC power everywhere is that we can use transformers to step up and step down the voltage in any way. All you have to do is wrap a bunch of wires around an iron core and they will induce an electromagnetic field that propagates through it, then wrap more wires around the core on the other side and that field will induce a current in those cables, simply vary the number of turns of wire around the core on each side and you can change the voltage according to that ratio.
It is quite good, it allows us to transmit power through overhead or buried power lines that operate at thousands of volts, which which allows those wires to carry a ton of power for their size because, while the cross-sectional area of ​​any given conductor affects how much current it can safely carry when the voltage increases, it can carry more power, i.e. , watts, with the same amount of current and therefore a relatively small cable, this allows us to transmit power over long distances economically in near megavolt range substations. You'll step it down to a more reasonable 11 or maybe 32 thousand volts for neighborhood distribution, and just before it enters your house, you'll step it down by a final transformer that delivers the relatively low final voltage to your home.
Now normally you just take a couple of wires to the ends of the secondary winding of the transformer and that's it, that's what you'll find in most countries in the world when it comes to a standard single phase electrical service, we'll just take our three phase for the right . Now the secondary winding produces a potential of 240 volts and therefore you get 240 volts from that transformer and believe it or not, that is exactly what our transformers do: they produce 240 volts in the secondary winding like yours, but the strange thing is that this is the United States. We are not going to settle for connecting two miserable cables to our transformers, that is simply un-American.
We know that we should have three, that is one more and therefore better. Obviously, this is where the weird stuff happens. Our transformers don't just have taps on the ends. of the secondary winding we put a third center tap right in the middle or center of that winding in its middle and that center tap becomes a reference to ground and that is what defines our neutral. By doing this we create what is called phase power divided and we end up Let's continue with what behaves as if there were two 120 volt potentials 180 degrees out of phase with each other across either of them and neutral, you get 120 volts, but when you cross the two phases you end up with the full 240 volts that produces the transformer. so now let's go back to the electrical panel.
I'm going to take the lid off so you can see what's going on inside. This is the part where I say don't try this at home. There are many things inside this box that I can kill you if you touch them. I understand pretty well what those dangers are here, good enough to run some new circuits without getting hurt or burning the house down with so far a 100% success rate, but this is not something that plays, I'm showing you mine so you don't need to see yours, it's okay, this is where the magic happens. I know for those of you in Europe this seems terribly gross and terribly unsafe, but it's okay, we're fixing it.
At the top there are three thick wires coming from the outside meter box, but ultimately from the transformer the two outside wires are live at a potential of 120 volts to ground. The middle wire is conveniently grounded and is also neutral. Yes, the middle cable is connected. a ground rod outside the meter box in addition to being connected to the center tap of the transformer for those who didn't already know, the ground plug and the neutral plug of your outlets usually end up in exactly the same place eventually, does TRUE? Here and the other side is weird and I don't want to get into that right now because my brain hurts and there are particular exceptions, so we'll just avoid that whole can of worms if I take a voltage measurement across this wire. and the neutral you will see that it is 120 volts or so if I measure from the other wire to the neutral it is also one hundred and twenty-something volts remember that those two pairs of wires are through only half of the transformer they conveniently end on the panel in that same orientation this is the left side of the secondary winding the right side of the secondary and the center tap of the secondary you will only get half the voltage from the secondary if you cross only half its length but across the width In fact, those two outer wires get 240 volts or are closed anyway, those two wires are at the ends of the transformer secondary, so all the potential is there, but it needs to be across those two wires, not just across one of them, and neutral to get full potential and that's why our 240 volt circuits are on these weird double breakers.
The lugs up here feed a pair of bus bars that run down to the center of the panel. A circuit breaker contacts that bus bar and provides an internal connection. link to an outlet on a screw terminal, the circuit breaker can interrupt the current path from the bus bar to the terminal, either manually with the switch or automatically in the case of an overcurrent event. This here is all a typical US circuit breaker if it is connected only to the live or active side of the circuit the neutral side of any circuit goes directly back to the panel if you look in the two spaces where there is no circuit breaker installed you can see the contacts of the bus bars to which the circuit breaker will be connected at the bottom of the circuit breaker, this contact will be attached to the bus bar which, through the switch contacts inside the circuit breaker, will eventually reach the output terminal.
The other part here is just to physically connect the breaker to the panel more robustly to trip this plastic pin. What happens is that the bus bars don't just go straight down the panel, they have a sort of interlocking comb shape. What this does is each alternate position down on the panel is fed by the opposite lug up there, you can actually see that. one of the points on the bus bar is connected to the right and the other is connected to the left. Now if you look at these two breakers, they both feed their own 120 volt circuits, but they are not powered by the same wire at the top, look at these two breakers, there is actually 240 volts, that is because one breaker is connected to this wire through the bus bar.
I'm pointing to the one on the left and the other one is connected to the other one, which is the right one again. Each of these circuit breakers powers a different circuit. If you follow the wire that comes out of the circuit breaker, you will see that it joins with a light neutral and a ground in one of these various wires, those wires go to the different circuits in the building or rather they are the various circuits in the building and in the circuits of 120 volts through the black hot wire and the white neutral wire you have 120 volts, the circuit breaker is there primarily to protect the circuit from overloads and damage to the conductor or It is worse to start a fire, but in conjunction with a grounded appliance, It will also remove the voltage if the 120 volt potential comes into contact with the grounded case because that effectively becomes a short which will trip the breaker more or less instantly, but that's not important right now. but remember that the measurement we took on these two breakers, these two next to each other, was 240 volts.
If you want to get a 240 volt circuit from this panel all you need to do is create a circuit on both bus bars and that is what it means They are double circuit breakers. These are called double-pull circuit breakers. When you install one of these on the panel, it takes up two spots so you can access both phases. It's actually just two circuit breakers linked internally, so if half of it trips. In fact, both of you, in some cases, can make a 240 volt circuit with two single-pull breakers as long as they join their trip levers and are the same size.
Just to be clear, not all brands or styles of circuit breakers will suit you. they allow it to be done. and it may not be up to code anymore, but it's an interesting possible fact and this brings us to another interesting fact: many of our 240 volt devices here run on two hot wires and don't have any neutral as you see the device. You only need access to the neutral if you also need access to 120 volts, some devices do, but many don't. You may be wondering how we connect our 240 volt devices to power. Do we have special plugs for that?
Yes, but sometimes not too. Many devices such as water heaters or air conditioners simply plug directly into a circuit, sometimes they go through a service disconnect which may also be fused depending on the code and device, although some other devices have plugs, we have strange plugs galore. over here, look at this clothes dryer, it's plugged into this bad boy, this 7.2 kilowatt EV supply equipment, it's got one of these in there, did you notice that the plug on the dryer had four prongs, but the charging station only had three? That's right, the charging station only has two hot spots and a ground connection with no neutral connection at all, but the dryer has a neutral; probably the only thing that really means that is the little light bulb inside or suchMaybe the motor is a 120 volt motor, the same for a gas dryer, but the heating.
The items obviously need 240, but the charging station doesn't need 120 at all, so now you only have the two hot spots. I'm sure many of you are wondering, but why do they do this? What is the point? Who is the maximum? Mouse, well, here's the cool one. The thing about split phase power, even though we have access to 240 volt circuits, nowhere in this building or even this panel will you find a wire with 240 volt potential, except in really strange or intentional scenarios , you can't get shocked at 240 volt potential, you have to touch both hot wires, even in a 240 volt circuit the individual wires have only 120 volt potential to ground and that makes our electrical

system

at least something safer.
I can hear them all screaming, it's not the voltage that kills. you are the flow of current, it is the volts that shake, but the mills that kill, you are right, but have you considered this with any body of given resistance? The current flowing through it is proportional to the voltage. I don't know if he ever has. I've heard of this little equation V equals I times R that voltage equals current times resistance when you increase the voltage which causes the current to also increase and it's not like American bodies have a resistance smaller than yours, it is 120 volts safe, no, of course not.
I don't want to come into contact with it and it can still very much kill you, but in any given scenario, if someone is shocked, the voltage matters, you will always reduce the likelihood of major injury or death, if the voltage is lower , there is no magic point at which voltage suddenly becomes dangerous and without enough voltage, your body will not pass any current. I mean, take a 12 volt car battery as an example, it can put out literally hundreds of amps, many more amps than my breaker panel can supply, but 12 volts is not enough pressure to send any of that current into your body. , except in really weird circumstances, like electrodes looking at your skin, people get really obsessed every time I mention that 120 volts is safer because I guess they think I'm saying it's safe, I don't know.
It will become clear that it is not secure, and to be fair, any security benefit we might get from it is obviously negated by the fact that our plugs are so terrible. I mean, the entire length of the pins is conductive, you're just asking for an electric shock when you plug something in. you literally just have to hold it wrong and these big plugs are even worse, plus we have dumb as rock circuit breakers in most homes and we only put leakage current detection devices in bathrooms and kitchens so yeah we have a lot more opportunities to surprise us and that is in itself.
It's a big deal, but it doesn't negate the fact that, all things being equal, understand what I mean by that, in any given scenario where one receives an electric shock, a 240 volt shock is certainly worse than a 120 volts, yes, 120 volts. it's still very dangerous, it can still kill you, you still want to not be surprised, that's priority one, but it's at least a little safer, all things being equal, now to be clear, it's not just for safety that we've done this In fact, it is probably so. just a happy accident of our history dating back to the AC/DC wars and, for what it's worth, we never had a hard time finding raw materials for construction wiring, so the thicker wiring required for 120 volt circuits was generally not a big consideration meanwhile in much of Europe the savings allowed by using 240 volts were substantial, especially after the Second World War, and then there are the UK mains, look them up if you've never heard Talking about them, they are a strange and fun fact in the In the UK, they actually use split phase power on construction sites, in that case the potential across the two wires is one hundred and ten volts, interestingly, each wire It only has a potential of 55 volts to ground, this is done for the express purpose of increasing safety. 55 volts is even safer than 120 55 volts anyway, just above what power over Ethernet is, since these things used on construction sites are the reason everything works at 110 volts so I guess a good number of UK power tools can be used here.
Know? Yes, a quick note, for some reason a lot of people will refer to our voltage as 110 and therefore 110 to 20 or maybe 117 or 115 or even 125. It's okay for those of you who do that, it's just 120, but there is no specific exact voltage. For any power grid, it varies depending on conditions, so everything works within a range of acceptable voltages. I usually get something like one hundred and twenty-three volts here, but elsewhere you might only get 115 or even 110, okay, stop being pedantic about it anyway. That's all I really wanted to share with this video, a basic overview of the US electrical system so everyone is clear on the fact that we have 240 volt power, it's a little strange but it's there and we use it, It's not like we're in the dark ages, of course, and wait that about the fact that this is a single family home is important ah I recently made a video about fans and motors and how single phase power makes motors harder.
In that video I talked about how an apartment building could have 208 volt power instead of the standard 240 they seemed to have. confuses a lot of people, especially those of you who until now didn't know that we have standard 240 apartments, they often have 208 volts and their service panels because many larger buildings are connected to a three-phase power source when done in the form the most common Y configuration, each phase is 120 volts respectively to the neutral, but in any two phases it has 208 volts in those buildings, its electrical panel will be extremely similar to that of a single-family house, there will be two hot phases and one neutral, but those two hot phases do not come from a split phase transformer, but are in fact two of the three available phases of a three phase transformer and it is the difference in phase angle of 120 degrees versus 180 that makes the potential between the phases be 208 and not 240. actually geometry in a way or it's trigonometry, whatever, most of our devices that are designed to run on 240 volts will happily run on 208 and in fact will often have labels specifically that They say 240/208, the only real drawback to 208 is that devices that produce heat will only produce 86.7% of what they would on a 240 volt circuit, so if you live in an apartment building your stove will be a little less hot than it might otherwise be or if you have an electric vehicle charging. station installed on 208, it will load a little slower than on 240, but it's not a big deal, thanks for looking.
I hope you enjoyed this and if you didn't know this about the US you've been informed and you'll stop bothering me about only having a hundred and twenty volts about the only way our weedy little outlets slow us down is the portable stuff Hate, yes, our kettles and almost everything have a limit of 1.5 kilowatts for an 80% safety margin on a 15 amp circuit, but really aside from portable heaters and kettles, nothing is worse for having a limit 1500 watts and when we need more than that, we have options that we always had. Yes, our electrical system is very, very faulty and our receptacles just suck, they really are horrible, just terribly unsafe. but specifically for Brits and Australians their obsession with receptacle switches doesn't make sense to me.
I've gotten a lot of confused comments wondering how we're supposed to turn things off without unplugging them first. All of our things from vacuum cleaners to toaster ovens have their own power switch, you just don't have it, companies design things for you, assuming you have that little switch because that's not my problem, that's your problem, yeah, we let things plugged in all the time, but other than electronics, it doesn't consume power. I remember a comment I read that said the fact that our outlets don't have switches must be another sign that we are wasteful. Americans know there are many signs of that, but this is not one of them, you will never see them. convince me that your switches in the outlets are more than just a mild convenience, and for what it's worth, we put switches in our power strips so we have that option of addressing electronics with standby lights and vampire drains, oh, but? what about security?
My rebuttal simply unplugs the Anyway, you had to reach for the outlet to flip that switch, not my problem, your outlets are so inconvenient and there are no sparks that are not dangerous. A spark from the inrush current will not damage anything. Actually, some of you seem so scared about various things related to electricity. I don't understand, I mean the shaver sockets, I actually just put an RCD in the bathroom and being so scared their electric showers are disconcerting. I know our electrical system has its flaws, but your perception of how dangerous electricity is seems really off base. knocks and rings the mains really, what year is it now to be fair, your fuses and the starter, that's great?
I'll grant you, while they seem like a big foot hazard, I'd guess it's worse than the 120 electric shock hazard or the UK foot hazard. plugs someone should do a study anyway I really think you guys just need to relax there the electrician is back again that's what you'll find in most countries in the world when they do it to get it's full potential oh shoot that's not it en At the end of the thing, but you have to cross those two wires, not just cross one of them and neutral to get to the mouth, and it can still kill you, but you know, that's not how you write terminal lines, this Another part is just yes.
I got it backwards, I lost it, I've lost track of which side is which, which is which, which is, on this side, yes, our kettles and portable heaters.

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