240V is the Standard US Household Voltage (Kinda.)
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- Опубліковано 5 чер 2024
- OK, so I’m being a bit facetious with the title.
Obviously I and most everyone else knows that the vast majority of American household stuff is powered at 120V. Almost all receptacles and (nearly) all lights in a home are indeed supplied at 120V.
But! It’s not as simple as that. Maybe the video title is a tiny bit of clickbait, but it’s also more or less true. Most Americans do indeed have 240V supplied to their home, and that is the line-to-line voltage. The transformer is rated for 240 Volts with a center tap that happens to be referenced to ground/earth, and it just so happens that the potential difference between the center tap (ground) and either of the two lines is 120V RMS.
So we use the lower of the voltages available for most of our electronics, small appliances, lights, and all that kind of crap. But, as I mention in the video, 240V is widely used for hot water heaters, air conditioners, clothes dryers, stoves, ovens, hot tubs, electric car charging and even whole-house heating. I use it for computers and related equipment.... for some reason. But that's a video for another day.
For the full transcript and perhaps more information eventually or whatever, you can check out my website.
s.co.tt/2019/09/09/240v-is-the... - Наука та технологія
Wow, I totally forgot about this channel! Please post more than once a year.
One comment on what you say at 1:40. The US does generally carry out a neutral wire for the primary distribution. It is grounded in many points and shared between the primary and secondary systems. So there is multigrounded neutral for the primary return path, it's just the same wire as the neutral/messenger for the secondary 120/240V wires. This shared neutral arrangement can sometimes lead to small stray voltages/currents on customer ground systems because it's actually primary current returning to the substation via a customer ground rod or water pipe. Some current goes through the actual earth, but much of it takes the metallic neutral conductor back to the substation.
In the EU (at least in The Netherlands) we have “3 phase” in most homes that delivers 380v which is used a lot for applications such as induction stoves and such. In fact, most stuff that needs 240v in the US, needs and gets 380v here.
Same in Russia. In homes we have 230/400V
Today its not 380 but 400 volts in the Netherlands!!So the voltage is today single phase 230 volts.If you are a electrician you should know that by now,its already about twenty years this way..🤨🤨
We have 3 phase power in some apartments and commercial establishments in N. America, as noted in the end of the video. It's 120/208V. This usually requires special dryers, stoves, etc., that are available to landlords.
@@dougbrowning82"LandLeeches" - fixed it for you.
One of the most interesting, easiest-to-understand videos on this I've seen. Thank you so much for posting! By the way, I love the ninja theme.
as someone from the uk i had no idea? you learn something new every day, great video.
Great content with especially high quality effort made toward lip syncing.
Seriously, nicely done and explained.
Excellent video! I also like Scott's senses of humor too ))
Fantastic video! Thanks, Scott!
Hey, I interned at PSEG back in my college days. They're slowly moving all local distribution away from the old 3kv or 13kv system to a newer 33kv system. I recall seeing where in LI you live from your thermostat video (I wont list the town in case you only showed it accidentally) but PSEG has more or less moved most things in your area to 33kv at this point.
You? Are still alive? I really like that! Great video, very interesting!
The ground isn't the return path, there's a neutral wire which is shared with the secondary that is the return path
Seems like he missed this while studying up on this video because that’s not how it works
That's so weird, I thought of you for some reason earlier today and then you post a video.
I just got finished watching a different video talking about 240 volts being out of phase or not and the consensus was a lot of times the measuring device is what is showing out of phase but that the actual power coming in is in phase at 0°. His explanation was that most lower end oscilloscopes you connect the ground terminals to the neutral which gives you the out of phase. If you were to try to measure it where you take one of the ground terminals and put it on L1 you would blow up your oscilloscope. He showed this by using an isolated oscilloscope. Bottom line was if it's out of phase you have to question is it the device that you're using to measure with that is out of phase or is the source actually out of phase
1:40 nope, not "referenced" to ground. Ground return is highly unreliable and highly dangerous for high voltages! Forget the Ohmic losses, power companies would go broke paying wrongful death lawsuits if they used ground return. But the Ohmic losses would also kill a business. The primary and secondary share a common common wire, meaning that what you think is the "safe" neutral wire in your house has as much as 21 kV potential against the power pole outside. If you lok closer, you'll see that common is used as a support cable for all the house drops, and eventually runs back to a 3-phase transformer. Making it code to tie the neutral to an earth ground in the house (and keeping the primary wire far from reach) helps prevent electrocutions, but it's an unnecessary risk to save a little copper. Americans have voted, and they chose cheaper and "what I don't know can't hurt me."
L1 and L2 are *in* phase, but opposite polarity. This is single phase power, so one phase, two poles and a center tap. The center tap makes a voltage divider. If the tap had been in a different place, we could have had three different voltages. There's a good reason why it's not that way, and that's because if there were appreciable neutral current, the utility would need to go ahead and make three separate circuits. Six wires costs more than three, so it's not done.
A split phase power drop is always 240VAC in the US. No, it wasn't 230 or 220 (not by design anyway), though some older circuits apparently were less than 120V, which is why we see those numbers on older stuff. My home town had 100V DC street lights that were originally powered by an Edison generator. When we got grid power, a special transformer / rectifier was installed. Having dual voltages with a voltage divider started with Edison DC systems, BTW.
boss your all information very useful thanks lord
thank you, I have this 220v input power supply for cisco nexus 7000, its chapter says it works with "high line input" only, I don´t know what that means, can you help me?
great video , thanks
Very well explained and shown! A challenge. Without saying that the oscilloscope shows it, what causes the (according to you and many others) 180 degrees out of phase. It is, as you know, single phase in and out of the transformer. I disagree with the term and say that is only on an oscope that it seems that way, but in the transformer it is not.
So, what in the secondary of a single phase 120/240 volt transformer can cause a 180 degree phase shift?
Respectfully, Kevin
It is nothing complicated to do with 3 phase or AC reactance. 180 degree phase shift (or "out of phase") is just a way of saying the signal is inverted or the other way round. Shift a sine wave 180 degrees and it is an inverted copy. It is fairly meaningless to talk about a positive and negative version of an AC signal that is itself inverting at 50/60 HZ.
Which is down to how the leads are connected. Take the DC equivalent where you have a 12V battery, which is actually made of two 6V cells in series. With a meter put the negative lead (your reference) at the -ve terminal of the battery. At the other end of the battery you have +12V, and in the middle between the cells you have +6V. Now put the negative lead of your meter at the central join, as your reference. You now have -6V on one end of the battery and +6V at the other.
That is what is happening here. On the oscilloscope (as in the AC supply) the centre tap is the 0v reference and the live ends appear as sine waves inverted with respect to each other.
As with the battery you could place the oscilloscope reference at one end of the winding. The centre tap would then be a sine wave at 6V, and the other end a sine wave - with the same phase (not inverted) but double the size at 12V.
SAFETY NOTE - NEVER connect an oscilloscope input in ANY WAY directly to a mains supply - always use a low voltage transformer. The 0v reference of an oscilloscope is usually connected to its case and ground.
@@JC-jv5xw I believe we agree. It is the way the oscilloscope is connected and shows up on the screen is why people say that the sine waves are 180 degrees out of phase. I have seen representations of two sine waves one going up and one going down and saying that each is 120 volts and therefore 240 volts. That is bogus! It would be zero volts. They would cancel each other out. A 240 volt sine wave is twice the size of a 120 volt sine wave. An tiny point in time, the three sine waves emitted from a transformer have to be at zero volts and maximum volts at exactly the same point in time and going in the same direction.
Have a nice day sir! Respectfully, Kevin
@@JC-jv5xw Why is it your channel was started today?
That means that we in Europe have 3x420V household power supply (considering phase to phase voltage)
Forgot this channel existed
In the au we have 240v on 1phase we dont have 120v unless you use a plug in transformer but none of our appliances use it
It is actually out of phases 180 dagrees for sure but the neutral wire perspective is that it crosses 0 volts at the same time so I think the out of phase or in phase ment that it’s according to relativity and whether it works together
And do You know how it is in solar farms in America? is there 120/240 volts or maybe 3 phase 480 v for example' I know that wind turbines generates 600.v
hes back niceee
0:58 😂 My side hurts from laughing so hard! Why you gotta do Florida like that?!
The neutral is the return path and it is grounded, hence why it is called the grounded conductor. The return path doesn't literally travel through the "earth." It is grounded so that the ground and neutral have no potential between them. There is an actual neutral wire that the current travels on throughout the whole system. Electricity doesn't go to ground like people often think.
Ground return is obsolete, but still used in some areas. I've seen it in rural Saskatchewan, where a single wire runs for several kms (miles for those in the USA) on pole lines beside the road.
What a video!
U.S. uses line voltage[ phase to phase or rather split phase ] as 240v with 180 degree difference and phase voltage[ phase to neutral ] as 120v. In India , europe - line voltage is 400v with 120 degree difference between each pair of 3 phases, and phase voltage is 230v.
Its because its 3 phase and 230 x 1.732 is 400
@@mr.3phase228 sure. to be precise .220v x 1.732 = 381v, 230v x 1.732= 398v, 240v x 1.732= 415v.
Hey man, nice video. I'm from South Africa and we use 230V outlets in our houses. Now my question is (I'm by no means an electrician, just a nosy guy), why does America use 120V and not just 230V?
Because by the time 230 became the standard in most of the world, Most people in the Americas owned a lot of appliances like washing machines, Refrigerators, Electric ovens, ETC, So it would be too expensive for people to replace all the appliances. (Idk if this is true or not, Seems true because this is what all my research said...)
And there was 3phase! With it's 120/208v
Hello I have a question can I plug a European 240v 50Hz AV receiver into a 240v 60Hz USA outlet?
The connectors are mechanically different, so no.
You would have to change the plug. In N. America, a 240V 15A outlet (NEMA 6-15R) has the current slots horizontal, the ground is the same as its 120V (NEMA 5-15R) type B counterpart.
Will things from England 240 volts ans germany 220v work on our system phase to phase European us 220 phase to neutral
That’s a question I’m trying to answer as well. I haven’t been able to find a single video on UA-cam that addresses it. Frequency considerations aside, will the 240 volts from USA run appliances from around the world that show 230 volts +/- 10%?
Yes, as long as they are resistive loads. 220v lamps and heaters work just fine. But motors and synchronous clocks that are dependent on frequency for speed precision will run fast
I'm actually tearing myself when I think about it, 120 v are safer and by renewable energy 12 v system is getting popular so 120v is though more effective, but when we talking about for example very powerful devices like some hair dryers, the american breakers 120v 15 amps it's not enough and it makes them turn off (and Japan has only 100v). But in the other side Americans have a few kilovolts nearly houses and I don't how about other countries but I,m from eastern europe and in the rural areas 400v lines are too long, my house is 1 km from the transformer, and look that we have medium voltage even at home, 10000 v generates when the car turns on, 10000 v is in the kinescope tv, and 4 to 10 kv flash is in the copiers, so maybe everything is possible
In the USA, 120V 20A circuits are common now.
Can an America 240v washing machine work on British standard current
Consult the manufacturer.
Scott in the original recording:"Hi everybody! I am Scott and this video I wanna bluh bluh bluh? bluh bluh! bluh bluh bluh."
I'm very lucky to live in a country with 230V Single-Phase and 400V Three-Phase electricity with 50Hz...
But how do You think ' is that a limit? do You think they would try to increase tje voltage again?
@@maciejgromek2368 Usually it can up to 415V.
How does that affect your life in any practical way?? I lived in Europe and it didn't.
@@liberoAquila right now may be the answer. 3 phase do allow EV car charger, my current house which still in single phase unable to use EV chargers.
This is exactly the same in The Netherlands, we receive ~230V (1 phase) / ~400V. (3 phase). I do not know about how other EU countries distribute their power.
We have the same system in Russia - ~230V (1 phase) / ~400V. (3 phase).
I really would like u to explain more about being earth returned voltage because that’s not how it works here and the wire under the one wire is ur return and it’s only kept at ground voltage and I will try to leave the links attached so u can study up
Great video!
One thing I'm interested in now is how is a phase created. I understand we receive two phases to our homes in the United States and when you use one of each together it creates two phases 240 volts.
If I understand correctly phases are about timing on a 360 degree wheel, sort of anyway.
Is it perhaps as simple as phase one at the power station is created for 180 degrees and then phase two is created for the next 180 degrees?
Your view of phase as timing on a wheel is accurate. A single phase generator has one winding. Therefore makes only a single phase, but there is room on the wheel for two more windings and if they are spaced evenly you can get three phase electricity. (In reality there are more than three windings in multiples of three. This allows generating 50 or 60 Hz with a lower RPM on the generator.) If you live in a high density area in a 120v country you probably don't get 240v you get a measly 208v because you get two phases 120 degrees out of phase from a wye transformer.
If you live out in the sticks you will have a transformer connected across two phases of a three phase distribution line. The secondary of the transformer is a center-tapped 240v. Using the center tap as neutral results in two phases of 120v 180 degrees out of phase because that is what transformers do.
@@billelkins994 I don't live in the sticks, but in an urban area (Oakland, CA). Our neighborhood is served by 12KV three phase distribution, with two of the phases connected to the primary windings of the transformers on the poles, not one distribution wire and a ground as shown in the video. The secondary taps have a center tap which is grounded at the transformer, giving 120 V 60 Hz across one live wire and the neutral and 240 V across both live wires. The center tap wire, or neutral, is also grounded at the service entrance. One half of the incoming power goes to each side of the breaker panel, so 240 V circuits connect to both buses while 120 V circuits connect to one bus and the neutral. Newer homes also have a separate ground wire, which my house, built in 1940 with post and tube wiring, lacks. Only new circuits added have the currently normal three wires (hot, neutral and ground) for 120 V or three wire (hot, neutral and hot) or four wire (hot, neutral, hot, and ground) for 240 V circuits. We have 240 V for our electric range and electric clothes dryer, all other circuits are 120 V, 15 amp for lighting circuits and 20 amp for utility circuits.
Some of the houses in our general area are older, and some have only 120 V (originally 110 V) service to this day. You can tell by the number of wires entering the house from the secondary lines in the power poles. Most have been upgraded to 120/240 V over the years.
@@DAB2640 You must live in the sticks. You have your own house. Now I do live in the sticks. I provide my own water and sewage treatment facilities. The only off-site service I use is electricity.
What is the service amperage in your 1940 house? I assume it is not exactly the same as built in 1940. My parent's house built in 1954 started out at 65 amps with gas heat, but now is 200 amps with a heat pump.
Do you still have any knob and tube wiring? Parent's house still has two-prong outlets except in a couple of additions. No K and T wiring.
Checked out some Oakland houses on Zillow. I can't afford to own a house there.
@@billelkins994 My neighborhood seems suburban, but we are within the urban limits of Oakland. The subdivision map was filed in 1938 and refiled in 1939. The house originally had only a 30 amp fuse box. A previous owner upgraded to 120 amp circuit breaker service (and insulated the outer walls), leaving the original circuits on the 30 amp fuse box. I replaced the fuse box with a circuit breaker panel. Circuits added have modern wiring, but most of the house is still knob and tube with fabric insulation on the wires. We have only a few grounded outlets. I had to ground the outlet for my computer myself. We have a gas water heater and a gas furnace, but electric range and dryer.
We bought in 1993. Now houses in my neighborhood are going for over a million dollars. Naturally, in 1993 we didn't pay nearly as much!
The house I grew up in in Los Gatos was built in 1903. It also didn't have grounded circuits. I helped my father ground an outlet for a room air conditioner back in the '70's. That house originally had an oil-fired furnace converted before they bought it in 1954 to gas. My parents replaced it with a gas forced-air furnace. It had a gas water heater and range. I can't remember if the clothes dryer was gas or electric. That house was sold in 1991 and may have been upgraded since.
@@DAB2640 Your neighbourhood substation is providing 3 phase distribution and your local transformer primary is wired between two of those phases. This method is used in densely populated areas.
0:58 "California" represented by a lowrider XD
very nice vedio thank you
I hope the us changes their voltage from 120v to 230v so Philippine appliances work there
I only get 110-112v from each receptacle at my house.. Even straight from the breaker box, I only get 112v. Aren't I supposed to get at least 120v?
The nominal voltage may vary plus or minus 5%. You are supposed to get at least 114V.
@@GH-oi2jf My issue was my multimeter... it was out of whack.. bought a new one and now I get 121v.
Nice description of Florida😅
I don't know if this is on topic, But don't you love it when you Wall outlet is connected to a random light switch. (This was sarcasm if u couldn't tell 🙃)
It's for when floor lamps were the norm or in rooms with little to no overhead lighting.
Its 250VAC, they shunt it on 2 circuits to make 125
3:11 There are switched sockets there?!
7:14 haha
@Marvin Mktavish
Oh, I see. I'm accustomed to British sockets where almost every socket is a switched socket.
We do have combination switch/outlets here that fit a standard duplex cover. They usually come bridged, so the switch controls the outlet, but the bridge can be broken to separate them. They aren't very commonly used, however. We also have dual switches, that also fit a duplex outlet cover.
120v in the US he all over the place I don't know what he talking about
interesting.
Yea but what about those damn cheap plastic gizmos!
i have underground wiring and i live in Toronto
We have underground in all new neighbourhoods and parts of downtown in Winnipeg. Even in old areas with overhead wiring, you can apply to have an underground service via a riser on the nearest pole if you're building a new house.
Earth return conductor @ 1:44 ? Common the world over"?
I can hardly believe this. We only use SWER single wire earth return in very rural areas. Not town. As the worms don't like it?
I'm stunned at American electrical systems. Not to mention the waste of copper
and if America would theoretically change the voltage to about 220v the plugs and sockets would leave the same, like NEMA-5 would be for 220v ?
The USA has a 15A standard for 240v: NEMA 6 (and NEMA 2), the tandem plugs. If we were to convert to 240v, we’d probably use them
@@davidpar2 thanks for the answer I think that it was not the best idea to change from 110 to 220 v in europe
@@davidpar2 And what do You.think about european plugs ' I mean about the fact that sockets are recessed and plugs pretty big with round pins. Do You think these are advanteges or disadvantages?
@@davidpar2 You can have 240V circuits with NEMA 6 receptacle now if you want. Tell your electrician you want them for air conditioners.
@@maciejgromek2368 We could benefit from sleeved prongs on our plugs. Australian plugs have them, and they're just modified NEMA 10-20 (obsolete in N. America).
niceeeeeeeeeeee
Libya 230 V 50hz
It's always funny, when Americans claim they had a 240V system. Maintaining the same argument, everyone over here has a 400V system. Furthermore, we have 3 phases (120 degrees apart), not just two. This allows us to use smaller wirings (usually AWG 13 or smaller, even for air conditions, stoves/ovens or saws) for the same wattage, and smaller breakers (the normal breakers are 16A, rarely 20A)
Yes, providing 3-phases to every household is more expensive than distributing with the stone-age split-phase system. That's the money that had been saved by the electric companies before, on the expense of the customers.
And to make it clear: Every computer and most of the appliances sold in Europe can run on 100-240V/50-60Hz. It would only be problematic with appliances that have a motor ... (like a hair blower, for example)
But is that 400 v is a limit ? Do You think they would increase the voltage again
@@maciejgromek2368 We speak about private households here, where 230/400V is the limit.
Industrial buildings or big farms can have higher voltages (3 phases as well), though, like 500V or 690V ...
@@manofnorse I'm actually tearing myself when I think about it, 120 v are safer and by renewable energy 12 v system is getting popular so 120v is though more effective, but when we talking about for example very powerful devices like some hair dryers, the american breakers 120v 15 amps it's not enough and it makes them turn off (and Japan has only 100v). But in the other side Americans have a few kilovolts nearly houses and I don't how about Your country but I,m from eastern europe and in the rural areas 400v lines are too long, my house is 1 km from the transformer, and look that we have medium voltage even at home, 10000 v generates when the car turns on, 10000 v is in the kinescope tv, and 4 to 10 kv flash is in the copiers, so maybe everything is possible
@@maciejgromek2368
Point 1: From the statistics: There are more (electrocution) accidents in countries with 100-120V than in countries with 220-240V. And you can see a lot of dangerous DIY here on youtube (~80% from the US, ~10% from India). Almost all of those installations would be forbidden in my country, as minimum safety and electrical code compliance requirements are not met.
Point 2: As I already said, having 230V or 3~400V makes cabeling easier and cheaper for the customer (see above). Calculate for yourself how many Watts you can pull from 1~230V@16A (L,N,PE) or 3~400V@16A (L1,L2,L3,N,PE)
Point 3: I don't know what lines you (still) have in your country. We have underground cables that are 1-2 kilometers from the transformer, and the voltage is fully stable (and speaking of outages: We had only 3 in the past 50 years, all caused by lighnings not by any other issues).
Finally: I'm sorry, but if a private household gets a 10kV line and an own transformer, then there is something inherently wrong in your power distribution system.
I live in western Europe.
@@manofnorse If I may say about from wider perspective
I’ve been talking on forum with american electricians and they told me that America should have 240v, but You know , Europe had also 110 v but we could change and everything started from like 50, than 90, 100, 110v so when now europe says the most about globalization etc. that increasing was not the best idea from that point so I can't agree with argument I've heard that America or Japan are technologically recessed because they have lower voltage ..... You say that 400v can be send on pretty high distances but it’s sometimes exagerated especially in the poor countries where nearly by the transformer could be 280 volts and on the end of the line only 160 v …… But I can't find anywhere why exactly 230 and not.for example 350 volts ' is that from that Nikola Tesla calculated that 240v 60 hz are the best parameters? So 230v 50hz are very nearly ?
This wil be informative if you can reply on the comments
I am challenging the statement that the sine waves are 180 degrees out of sync. I ask for you to think about a few comments and would like your thoughts afterward. There is only single phase coming in. One sine wave at 60 hz. So if there is only one wave in, how can there be two different waves coming out? Forget your Oscope just for a minute. Try to answer the question with common sense. I do not think you can come up with an answer. So, here is my statement. If you put an Oscope on L1,L2, and common in scope to neutral, you will get the waves you show on your scope. If you look at only the first half of the sine wave for direction, assume electrons flowing L1-L2. The scope is reading L1 to N and L2 to N. This not the direction of electrons on the first half of the wave. There are three waves at exactly the same point in time. They are (direction listed) L1-L2 (240v) L1-N(120v) and N-L2(120v). So if you say on an Oscope 180 degrees out because of the connections, I agree. But within the electrical system all sine waves increase and decrease at exactly the same time. They have to. Please let me know your thoughts on this. Excellent video! Respectfully, Kevin
Kevin Coop. No they are 180deg out of phase, if L1&L2 were the same phase they'd have 0V potential between them
Nathan I assume that you have read my explanation and are not agreeing with it. Hopefully you drew a transformer and have it all worked out. Please give me a full explanation of how a single phase sine wave in the primary side gets changed and operates at different direction and or in different point in time. Be very specific please.
In your comment, you say that from L1 to L2 on same phase would be 0 volts. If you are talking about a termination point, I would have to agree. But L1 and L2 are two points of a single phase transformer. One single sine wave not two. Twice the amplitude of a 120 volt sine (in 120/240 volt system) and at exactly the same point in time. If you remove the center tap and ground completely, you will have the 240 volt sine wave only.
Looking forward to your telling me what causes 180 degrees and out of phase. Do not just say that is what you learned in school! That would be very disappointing.
Respectfully, Kevin
@@KevinCoop1 Battery terminals are 180 degrees out of phase. One terminal is positive and one terminal is negative. Batteries don't work if both terminals are positive. Same is true if both terminals are negative. A transformer secondary is no different. When one terminal is going positive the other terminal is going negative and they do this alternatively.
Two inputs on the scope. One input is connected L1 to neutral, the other L2 to neutral. When L1 is positive, L2 is negative. When L1 is negative, L2 is positive. If you connect only one scope input L1 to L2, there is only one sine with double the voltage.
0:39 why in god’s name did you use a photo of Jeffrey Dahmer?