Best and most thorough explanation of this I’ve ever heard. Many licensed electricians can’t explain this. You made it simple enough to understand yet thorough enough to get the correct amount and kind of information across. Excellent job!! The key is at the end when you said they both take turns being supply and return 60 times per second. I’ve known that for decades. But, no one ever explained the details of that in the way that you did. I’m a subscriber now… and fan!
he didn't really explain the neutral, and why it's normally seen as the return.. ( because it's grounded.. it has zero voltage to ground. making the other terminals both HOT
An interesting way to present that. It would never have occurred to me to line up a series of batteries and tap them for this demonstration. As an analogy it holds up reasonably well, but there is that whole AC vs DC thing that you did cover toward the end. Very clever. I give you high marks for outside-the-box thinking.
When I studied electrical construction at Kalamazoo Valley Community College, the concept of spit phase power for residential and some light commercial, was done with two 12 volt AGM batteries in series, that is how I first learned the relationship of transformer windings and the different voltages obtained with different taps.
I am a layman in this area. I sort of wondered but didn't even know how to ask that question. You helped me understand the question, and then the answer. Your explanation was perfect, brilliant. Thank you.
I think a very important caveat required in this video is that it is applicable to installations in the USA. Most of the rest of the world, 230/240v uses a phase and a neutral.
We don’t “ground a leg”, we ground the star point of a three phase transformer. 240 is obtained by taking a phase and a neutral. So you can have 3 separate phases of 240v off a single transformer. This is important to know because it is possible to have 400/415VAC behind a switch or a GPO.
@@hotswapster I have 80k followers on tik Tok you have just contradicted how they say European homes work. And how googled says European homes work. I have never been there but have a trip to Germany on Nov 28 of this year.
@@hotswapster if you Google "are European homes single phase" the search result say yes. That European homes are fed the same way as Americans homes. But we ground the mid point you guys ground the end.
@@hotswapster in American homes the mid point is grounded by the electrician and the power company. But in Europe the power company only grounds it not the electrician. Think neutral must be slang in Europe. How can you have a neutral when you only have on wire to reference it to.
Thanks so much....I have a tik Tok with 80k followers and a bunch of videos. I am just now trying to build you tube and Instagram. But check me out on tik Tok for the most content
@@Stevenj120volts Excellent explanation. Question, you stopped short of further explaining how the exposed neutral in this panel plays a part in what you described. Or does it play no part in what you described, ie the 240 v. Thank you.
I love this. I literally explained this to my father the other day. And this just cements my explanation. Although I wish I had thought about using series battery’s to do it. Bravo.
So, this may have already been asked here in the comments but, if I’m understanding correctly, here in the states, 220 is not actually 2 different circuits, but one continues circuit and the neutral “splits” it to 110? That is neat. And this was an awesome explanation!
I need 240 volts for my drier. Have 4 prung outlet and plug (ground, neutral and 2 hots) I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? Should I remove the white/neutral? Please advise.
What he didn’t explain is that when you wire or stack power sources in series, the supply is accumulated with the amount of sources that you use. So 10x1.5=15 vdc for example with the batteries.
Excellent explanation! I like the visual of a sine wave which shows a horizontal zero volt neutral line, a 120 volt positive upper wave and a 120 volt negative lower wave in single phase (1/60 of a second).
Technically this DC mock-up is correct as a an instantaneous snapshot in time. From an engineering or troubleshooting standpoint it’s important to note that a split phase system is in fact two phases at a nominal 180 degree phase angle. Imbalances between the legs can cause lagging, which can then cause voltage sags and associated greater or lesser amounts of current return on one of the legs on a cyclic basis. Probably only important to an electrician if you’re trying to troubleshoot sketchy or potentially improperly installed equipment.
I disagree with the second part. It is one phase split. Not two phases. If you cut apple in half you still have only one apple. It is the set up I show with the battery stack reversing polarity at 60 cycles per second
@@Stevenj120volts what you are describing is a DC to AC inverter power source. A split transformer is different because it is a true phased source and can respond negatively to lagging load from pole to pole. It does provide two phases (pure sine waves) but is not a proper multiphase system because the phases are at a 180 degrees from each other unlike a true two phase system, which is rare today, and which provided two phases at 90 degrees. Your example is a fine teaching tool but doesn’t provide a full description of the electrical theory behind split phase.
@@awheel you know it works? Like if I put a load on the battery stack the neutral will carry only the imbalance and disconnecting the neutral will cause and imbalance of voltages
@@Stevenj120volts yes … it does work. Like I said, it’s good for a general demonstration of the principle, but your phase theory is different from what’s actually happening in the xformer.
Thank you for this explanation. You got yourself a new subscriber. Been in the trade for three years and all the guys above me can't explain this situation to me, other than that's just how it works. 😂
Wow. I’m still trying to absorb this. Not an electrician, but understand enough to be dangerous as they say 😂. Seriously though, I never understood this and always wondered how this worked. It explains why back in the day, they never had a neutral running to things like dryers and stoves. Used to be two legs and the ground. That was it. That neutral wire introduced into two pole breaker situations came later on down the road. I was just watching videos, explaining how to search out an open neutral. I saw another RU-vidr do the same thing with a bank of batteries, hooked up to lights on two different banks. He basically used alligator clips for switches. You can literally see, depending on where the neutral break is, were certain lightbulbs, were getting more voltage, and others were draining less. Still trying to wrap my head around that. Your video just helped me to understand why. Because the neutral wire is tapped from the center! You made a comment about full potential being at the end. I think I’m slowly starting to get this. Unless I’m missing something here. Bottom line is from my situation, kill the breaker, identify all the circuits that are on that run. Turn the breaker back on, start with the closest circuit to the breaker and check each circuit neutral until I find a loose one, moving forward through the path of the full breaker circuit. This is an old house. I hope I can find this because it’s been a mess. Anyway, This was a really, really interesting video! Much thanks for this! And yes, as someone else said, thinking out of the box is awesome! Kudos!
Actually, the old stoves and dryers you're referring to are actually two hots and a neutral, no ground. At the terminal block there was a strap or wire that bonded the chassis to neutral, for three wire setups, these were prohibited as of the 1996 NEC, but because not all states and jurisdictions in the US adopted the latest NEC edition, it really wasn't until the early 2000s when the rule was enforced nationwide, existing installations are allowed to remain, that's why 3 wire dryer and range cords are readily available at any hardware or home improvement store. New installations are required to be 4 wire - Hot, Hot, Neutral, Ground, and the neutral bonding strap or wire must be removed when a 4 wire setup is used, and vice versa if moving into an older home.
This is such a good representation! The ONLY thing I would have added is a drawing of a transformer to show how your example is applied to the real world situation.
I think would easier if they taught new folks that we in fact have 240v service via a transformer at the power pole that has a center tap with a 120v potential.
This split happens again in some electronics that have an iron core transformer that steps the 120 volts down to like 24 volts but may have a center tap that also offers a dual 12 volt option so later in a circuit you can get + 12 vdc and a - 12 vdc supplies alongside a 24 vdc supply. This is more common in audio amplifiers though and with higher DC voltages
Thank you, that was an interesting demonstration. I always looked at alternating current as a pause and then a push, and then a pause , and then a push, not a give and take, im thinking the neutral takes away the empty box of electric, or the empty container of electric, or the spent cartridge, so to me AC is a push pause, not a push pull, if i get a shock from 120 volt, i can fell that 60 times a second, if it were a push, pull, it would cancell out itself, but the fact that it gives you a shock and then pauses, is (in my eyes) is proof that AC is push pause, rather than a push pull. But i really appreciate the video.
Good job brother, shits simple but hard to grasp for a lot of people. I always say a good electrician would make a great plumber and visa versa. It's all the same principle, just applied different.
Thomas Edison discovered this. In his DC power plants he used two dynamos wired in series with a center tapped neutral. Another name for the split phase service drop bringing power into your home is an “Edison Three Wire.”
This issue is a point of contension for a two wire 240v outlets or the three wire plug. The appliance drawings show a neutral on the appliance and a ground on the house outlet. They connect the neutral to the ground or is it the ground to the neutral. Their drawings are technically incorrect with a name change in the middle to make it work. The actual difference between a neutral and a ground is where the wire is landed in the breaker box. Addiitionally, the neutral and the ground are bonded in the breaker box at the first disconnect. This bonding makes them electrically the same voltage. To me this whole thing makes me worried about touching my oven or the dryer. I am still alive. My brian hurts just talking about this stuff.
@@TexasEngineerthat actually doesn't happen. Electricity always needs a path to its source. Sometimes it's back to the utility through the transformer or to earth. If you bond after the first disconnect, then yes you can allow a positive charge on the ground conductor. But since the ground goes to ground it could never hold a charge when wired correctly. It will dissipate a charge, but never hold a charge. So you really have nothing to worry about.
Near the start, you mentioned “wrong terminology” being used. That is correct, but you didn’t follow up on that thought to explain what is wrong with the terminology. What is wrong is that too often, people who are trying to teach AC to beginners lead them to believe that “hot” means “source” and “neutral” means “return.” Wrong! I see this again and again in YT videos. “Neutral” means only the conductor thst is tied to ground. “Hot” means a conductor that has a significant voltage relative to ground. Thinking that they mean anything else is the fundamental terminology error.
thanks for the answer. I found the problem: what happened is that only top 2/3 of power metal bars where brakers connect, had a horizontal piece of metal connecting both, left and right sides and the 1/3 bottom part where I installed the slim 30 amp 240v braker didn't have that little horizontal plate connecting both metal power bars. I had to use a regular bigger size double braker that touched that horizontal metal plate and that fixed problem and got me the 240 volts needed for drier.
The definition of Alternating Current is it is constantly changing in magnitude and periodically changing in direction . For transformers and AC motors to work this has to be so .
A transformer will generate output as long as there is changing amplitude, changing direction is not required (but it's easier to saturate the transformer core if using a change in amplitude without utilizing a change in direction depending on the application). Just FYI, Don
Wow fascinating info but what does this have to do with a transformer designed for use with AC voltage and current where the goal is not to saturate the core? @@wd8dsb
There are many 240 volt (single phase, by the way) appliances that require a neutral and a ground on top of line 1 and line 2. Those are utilizing that neutral for 120 volt loads with8n the appliance such as power supplies, clocks, etc.
@@wd8dsb np you need it an imbalance you can have 120 with no neutral as long as it balanced I have plenty of videos showing this in other demonstrations
@@wd8dsb I am 100% following what you are saying and I 100% understand where you are wrong and what part of the wiring diagram you are confused by. The 120v i your house comes from the two loads being put in series on a 240 volt circuit .I understand it doesn't look this way to non electricians that just learn to connect black to black and white to white. But it is true the neutral does not provide you with 120v the neutral give you balance to maintain even voltage when the loads are not balanced. I am Master Electrician with 28 years experience I am not confused by what you are saying I am explaining on a deeper level. You can have 120 volts without neutral.
@@wd8dsb that's my video the "he" that you said make the qualifier is me and not you you don't go between neutral and hot. It just looks like that because of the configuration of the panel. Sorry My content is for electricians its going over your head
To better illustrate the single phase nomenclature on the panel you could have show a single phase overhead transformer being fed one single phase of primary being converted to two hot wires on the secondary side.
Great explanation and demo but I’m still trying to wrap my head around whether or not my 240v AC/DC stick welder will function properly if I drop the neutral wire. Thoughts?
What about 240v appliances that have internal leg break outs for 120v components like timers and motors? They should not be using ground as a neutral tap so how do they do it with a three blade plug? Has using the ground been been the practice in the past on older 3 blade dryers and ranges for example?
Three prong plugs do not have a ground, they have 2 hots and a neutral. The chasis of the appliace would be bonded to neutral instead of ground. That is no longer to code because it can create a shock hazard in the case of an open neutral.
I understand they are not out phase when measured from top to bottom but how is it possible for them to alternate positive negative/supply return if one is not opposite polarity (mathematically 180 degrees out of phase)
Interesting. I always wondered why it's not called double phase power. I suppose since the transformer from the street is tapped off a single phase of the 3 phase power from the telephone poles.
Great setup. Teach the general theory about residential AC power services. Remind this was done with batteries(DC). Challenge: explain 3 phase power and why 2 pole is 208v and not 240v
208V can be a single pole. It's generally found in commercial/industrial environments. For me, I've only seen it on conveyor belt motors. Homes will only have 120V/240V. 240V is also 2 pole. 3 phase can technically be run to homes, even though it's not done. 3 phase is exactly what it sounds, it has 3 phases (legs) of power. Unlike single phase where it splits a leg off to provide 2 legs of power into a home, 3 phase has 3 individual legs going into a panel. Each leg is 120° out of phase from each other. So like he explained the positive and negative alternate between the 2 legs, the same happens in 3 phase, but only one acts as the opposite while the other 2 are either positive or negative.
@@TheForgottenMan270 nice. It’s a good finish to it. 208v is a single pole fed by a double pole breaker from a 3 pole wye that has a neutral in the centre after its been transformed from delta transmission lines. It’s possible that may be found in residential setting, mostly in rural residential or farm lands for their shop equipment. This opens the topic of transformers. L2L 208V L2N 120V A single phase residential power service the neutral is just like mentioned in the video. You had a good idea of this. Just needed to iron it out like a wrinkled shirt. @MikeHoltNEC good guy for the advance stuff that most guys don’t get a chance to see.
@@oshanehall3470the reason you get 208 is because their is no point at which you are 180 degrees out. You can only get 1.732 times out. Which will be 120 times 1.732 and we call it 208
Decent explanation, but i think you could have done more to explain the concept of time and phase as it equates to the sinusoidal wave. Good video none the less...
This fellow should have just shown a schematic drawing of a transformer. The telephone pole transformer has of course a primary winding and a secondary winding. However the secondary winding is center tapped. This means the secondary is actually like two windings connected in series. Each winding produces 110 volts. The point at which they are connected is wired to the breaker box as neutral. The 2 ends of the transformer are the hot wires/terminals. Unfortunately, the neutral is also connected at the pole to the ground that you stand on such that if you are standing on the ground and touch one of the hots, the electricity will use your body as a path to get back to the transformer. Makes sense huh?
I need 240 volts for my drier. Have 4 prung outlet and plug (ground, neutral and 2 hots) I am only getting 124 volts on each leg of outlet and on each screw/wire of braker and when combine both legs of 124 volts on either outlet or braker I get 0 volts. Replaced braker and still 0 volts. Any idea why can't get 240 volts? Should I remove the white/neutral? Please advise.
thanks for the answer. I found the problem: what happened is that only top 2/3 of power metal bars where brakers connect, had a horizontal piece of metal connecting both, left and right sides and the 1/3 bottom part where I installed the slim 30 amp 240v braker didn't have that little horizontal plate connecting both metal power bars. I had to use a regular bigger size double braker that touched that horizontal metal plate and that fixed problem and got me the 240 volts needed for drier.
Neutral is a just the center tap on the transformer, between the two end taps that make 240 volts.. tapping in the middle breaks the coil into two segments.. 120V apart AC POWER both sides are POWER AND RETURN.. ( hence AC ) the reason you don't need the neutral for 240.. is because you want 240v. so there is no reason for a center tap. ( the safety factor about the center tap. it is connected to ground.. so the voltage potential between it., and a person who accidentially touches ground.. will be 0. it only has a voltage potential with the other two taps..
