This man is a master at teaching... so clear. his body movements, his eye movements , hands all work in coordination with each other. his voice, easy on the ears... His brain the conductor of the whole operation. A pleasure to learn from...Thank you Dave.
Thank you, as a mechanical engineer I’ve always struggled with electrical concepts and this helped me understand much more about how the different windings affect voltage.
Dave your videos are so immensely understated. You're an absolute hidden gem and I can't thank you enough for making this material available. I'm an IBEW electrician apprentice in my 3rd year and I constantly supplement my school work with your videos.
Excellent instruction, and a perfect example of how clarity doesn't require fancy animation, just a clear grasp of subject, words, and pictures. Now for the love of all that's decent and proper, stop saying _"hot_ water heater", and change that "HW" to "WH". You don't need to heat hot water.
Thanks for your kind words and your attention to detail with "HW" and "WH". I will take note of this for future use as I have to agree fully with you. Also, thanks for engaging with B YENZER1's comments as I have been unable to allocate much time to reviewing comments, but you will notice that I have added a somewhat lengthy comment to your last one. p.s. By the way, since we're trying to be decent, proper, and particular with words, which phrase do you use? "I could care less" or "I couldn't care less"?
@@davegordon6819 - Well first of all, I never claimed to be decent and proper myself, so my phrasing is usually more colorful than either of those options. But I'm told by my neighbor who is an English prof and historian, that "I could care less" is the _older_ version of the two, contrary to common misconception. It was as if to say "You think I care very little now, well if you like, I can care even less." Only later did people misunderstand it as an error, and decide that it should be "couldn't care less".
@@pterafirma I've never heard that explanation so you (and your neighbor) have given me my new piece of knowledge for the day. Now I can go take a nap. Thanks again.
Other than you kept referring to the peak voltages as 120V which would be confusing to a beginner when actually Vp ≈ 170Vac or Vp-p ≈ 340Vac hence the need for capacitors with 370V or 440V ratings. Root Mean Square is just the DC equivalent hence there would be a straight line drawn through the sine wave to represent that average. Vrms = Vpeak/√(2). RMS is the only way to average a sine wave in case your wondering. It's also used to take an average in statistics to minimum the effects of outliers 😉 - 1st drawing - Single Phase - 2nd drawing - Three Phase (Wye) - 3rd drawing - Three Phase (Delta) I suggest adding "Ugly's Electrical References" book to your toolbox because it covers all this and much more in case you forget. Great video 😊
Dave, I was looking for the definition of a great teacher, and now I got it on this UA-cam video. You are beyond excellent and keep up doing this amazing teaching style.
You have simplified months of frustration in trying to understand these concepts. I cannot wait to check out the rest of your videos. I so appreciate the clarity you deliver. THANK YOU!
I'm blown away by your efficiency sir! All the little comments added explaining things for our green compadres shows how masterfully you teach. Thank you sir.
This is one of the best videos I have watched out of a lot out there that explains with this much clarity and expertise. Thanks for passing your knowledge how it should be with all.
Wow I wish I had a teacher like you when I was in trade school, nice job explaining and simplify something so complicated, please continue uploading videos!!!
Another EE here, and I like your teaching style, you dive just deep enough into the theory for the non-mathematically inclined to still understand the important concepts. It would be so easy to try and "prove" that you know the theory, but at the risk and expense of losing your audience, and that makes a poor instructor! You make it easy for those just beginning to learn the electrical trade to understand. Nice work!
Thank you, Dave! I've just discovered your videos while looking for some information about transformers. You combine two of my favorite subjects: electricity and math. Fifty years ago I was an electrician in the Navy. At that time, we were trained in single phase and three-phase delta and wye transformers. I understood it completely at the time, but never had experience with them since then and lost my knowledge of them. Now I understand them a whole lot better.
Fantastic video! I recently took over management of a 160 year old theatre that has a high leg delta panel in the projection room. Wanted to get familiar with the system. This video was incredible informative. Don't be worried. It did not give me the the confidence to monkey with the panel. I'll call a pro anytime this panel needs works.
Dude. This is awesome. Great way of explaining it. I totally get how this works, but being able to explain it is very hard for me and this way of explaining it is perfect.
I like the idea of the radius of a circle in terms of a generator, starting from west or zero axis , like a radar from west , north , east , south and to west. ! Radar or radius is from center point to the inner circumference of the circle ⭕️ . Diameter is from west to east or north to south, that is why a radius really is interesting like radar !
Well done. And I actually saw the fireworks first hand at work when one of the guys installed a bunch of new 120 V fluorescent fixtures to a 208V high leg by mistake. WE also had 277 VOLT stuff that people made mistakes with. Luckily we worked for BIG OIL. They could afford it.
The 120/240V thing was actually a late 19th century thing - all derived from the Great Fire of Chicago. Edison lamps were made out of carbon, and used 110V, however, other companies figured out how to make lamps using tungsten, a much more resilient metal and could work at 240V (carbon lamps burn up at 240V). Since adoption of electricity was much slower in Europe, the European utilities went with 240V as it saved money on copper and is more efficient. Our 110V system was derived as a split-phase system, because Edison noticed that some people's lights were brighter than others. So he designed the system as two 110V generators (this was DC, mind you) and connected them together to form a third neutral line. He realized by monitoring the current flowing on the neutral line, he could determine how bad the imbalance was and rebalance the grid so the same number of lamps were on each half so everyone's lights were the same brightness. In addition, if you needed more power, you had 240V (DC) available. Now, electrification was huge in the US - especially after the Great Fire of Chicago which meant everyone started from scratch, and skyscrapers were a thing. Gas lamps couldn't be lit more than a few stories up, and everyone wanted electric lighting. So much so that demand for light builbs was so big even though carbon lamps were obsolete, Edison was still making millions of them as the tungsten lamp makers couldn't keep up (in the late 19th century, they made around 10 million tungsten lamps, and Edison made nearly 60M carbon lamps. This changed about 20 years later in the early 20th century when carbon lamps were finally obsolete and replaced with tungsten lamps. However, by now the die has been cast - 110V had been around for so long, there was no appetite to change over to 240V.. In Europe, electric lamps were seen as a novelty, and very few people had it. The rich folks refused to install it in their castles, so when it came time, it was trivial to switch over. Oh, and the first war of the currents was between Edison and Westinghouse, not Tesla. The second war of the currents was between GE and Westinghouse which dictated if we'd use two-phase (Westinghouse, via Tesla's patents) or three-phase (GE, Edison had been kicked out) AC. Tesla is confused in these because Westinghouse bought Tesla's AC motor patent (and later all of Tesla's patents). That patent showed how a motor would work at 60Hz two-phase. You have to remember though, that just because of this, power was still not quite standardized as you could get DC, 60Hz, or 133Hz AC power (133Hz because Westinghouse managed to find a design for an electric meter but that required 133Hz to run properly).
133Hz from my understanding, was more commonly used with carbon arc lamps common for streetlights and in factories and large retail stores from the early 1880s until the early 1900s, because it flickered less than 60Hz. You also had very oddball frequencies such as 25, 33.3 & 40Hz, to name a few. The early days of electrification must have been a very intriguing time to live through. And all this was in major US cities, many farms and homes in rural areas didn't have electricity until after WWII, my grandmother recalled not having electricity until merely a few months before she married in 1947, born in a farmhouse in 1925 and lived to be 96.
Excellent video!!!! For the case of the delta transformer. As we can determine the current in each winding to determine the single-phase and three-phase load distribution in them and thus their optimal size, this in the case of being a bank of transformers.
Great video, I do have one question at 10:25 when you said that if you take any vertical point on the 3 phase graph and add it up you get 0. Are you referring to where the one phase peaks and the other 2 phases are intercepting underneath that peak? I assume you are subtracting the value of the peak from the values of the negative voltage phases underneath the neutral. Just threw me off when I heard you say that.
While 208 volts is a 3 phase voltage produced by 3 phase transformer bank, it is commonly used as a network voltage by utilities as a leg to leg voltage for single phase residential loads instead of 240.
Stupid question time. Are the line 280 wires Brown, Orange Yellow and the black, red and blue the outputs? Would you be running the Neutral for 120v in white? You probably have a wire color code video, I'll look. You do amazing videos. Some airhead talks about stringing beads and gets 100K subscribers, but real , well presented videos don't. Life isn't fair. Thank you for taking the time, the videos are great.
You may cover this in another video, but there is another reason to have a 240 delta system. If you already have a 120/208 Y system in your facility and need another service,NEC says the second service must be a different voltage, hence have a 120/208Y service and a 120/240 Delta service on the same building.
You're a very good teacher. I've been trying to find someone to explain this to me for awhile now, searching all over UA-cam and the internet in general and haven't found a single person that can explain this in a manner that I could understand until I seen this video. I appreciate that you took the time to make this. Thank you.
In my country the voltage between the phase and the neutral conductor is 230V +/- 10% and between any two phases it is 400V. Every other house has a three-phase connection.
In case I wanted to connect a single phase load on 208V, the two wires I have to choose from can be any live combination that is from the three live wires, What I do not get and I want clarity on is if am choosing any two wires from these three for single phase connection, how do I incorporate the neutral? Because here in Canada we use Black, White and Green for any single phase load. When you say 208V single phase around 8:45 minutes, how do i do the arrangement so that I incorporate my live wire, a neutral and a ground?
Here in canada, we dont have single phase 208V ( line-neutral ). Its like he explains, ( Line to Line ) is 208v And ( Line to Neutral ) is 120v The colors of your wires dont matter. You can always put some red tape on your white wire if it not a neutral, just to prevent mistakes or accidents.. but if its clearly identified as 208v, usually, nobody will think that the white wire is neutral.
Thanks for explaining a different method to calculate the HIGH LEG to ground. I did not know using Pythagorean theorem gives you 208AVC. I've always use Vector addition.
There are plenty of uses for the high leg. Many modern LED light fixtures are rated for voltages between 100 and 277 volts 50 or 60 Hz. If you use the high leg, make sure that you use a straight rated 240 volt breaker.
@@Sparky-ww5re No, but all 3 pole breakers are straight rated and some double pole breakers are. You can simply use the high leg as part of a multi wire branch circuit. There's nothing in the NEC that says you can't use the high leg to neutral. You can run three (2 wire) branch circuits from a three pole breaker. You can not however run a 4 wire branch circuit with a shared neutral from three single pole breakers. NEC 210.4B.
I did the HW chum rms = root means square center neutral opposing and pushing relativity of product Bus wiring Voltage = Points if differential potential of to points (Check out angle theta!!) as well as from which 120 degrees of the exact moment of the circuit became energized comparing the constant peaks per delegated cycle (Alternating Current and it's Value) while subbing out impedance with greater use of Volts and VA (Volt Ampere) to mediate or use the Load (What the conductors are connected two and their rating) for treatment of the new simulated resistance from use of Center Tapped Neutral Connecting within the center if the Wye Connect will split...not only the windings but the voltage. Equaling=B phase To High leg is 208V Make Sure You label!
10:54 I'm an electrician, and never understanded why the neutral ( X0 ) has to be " grounded " ?! I know what happens when it's not, but dont understand the reason... Is it only in case of unbalanced 120v loads in a star 120/208v ? But what if its 3 phases 208v star configuration, and we only put a load on phase A and B ( 208v single phase ) , and the X0 is not grounded, what happens?
Question: Where would a wye transformer like this one be used? It seems like the only place it would be good for would be structures requiring only 120V services. Are there any instances where straight hot leg to hot leg 208V would be needed? Aren't most devices 120V or straight 240V? I understand 3 phase where you have a high 208V leg, but I've never seen that high leg used on a single pole by itself, it's always used in conjunction with the other 2 phases to produce +240V at 3 points during the cycle.
another system worth an honorable mention, is, an open delta, typically 120/240, but occasionally corner grounded 240. I've seen this in rual areas, almost always on a farm setting, when most of the loads are single phase 120/240, with a smaller amount of 3 phase motors, typically a grain drier, augers and conveyer. The capacity of a full delta is not warranted, and the system can be easily recognized, by the two transformers, one being significantly larger, in terms of KVA, because all your 120V loads come off that one. the smaller transformer is the power transformer, this provide the high leg. Much like the full delta, open delta suffers from the same limitations, very difficult if not impossible to balance, along with the possibility of mistakenly connecting a single pole breaker to the high leg when 120 volts is needed. As such these systems are rarely encountered in new installations.
The high leg delta system although very seldom used in new installations, actually is a really cool system. Although all electricians know and probably have worked with the 120/208/240 delta at least a handful of times in their career, there is also yet another delta that is extremely rare and many electricians will never come across it, some may not even know it existed, but it's a 240/415/480 volt delta.
@@jolyonwelsh9834 for me it depends on the application. If I have a lot of single phase and three phase loads, I prefer the 208Y/120, as it's easier to balance the loads, and eliminates the chances that someone will accidentally connect the stinger leg 208V to a 120 volt circuit and burn up equipment, it's happened more frequently than an honest electrician would care to admit. Where I hate the wye system is in apartments and hotels with a kitchenette, the range tests my patients when I need to boil a pot of water (I hate electric ranges anyways, I'll take on gas anytime day or night) and clothes take longer to dry. If I have a bunch of three phase motors, with a smaller amount of 120 volt loads, I like the 120/240, 3 phase 4 wire delta better.
@@Sparky-ww5re There's a more expensive but thorough solution. Maddox brand transformers manufacturers a 3 phase transformer with a 240 volt delta primary and a 208Y/120 volt secondary. Have a 3 pole breaker to feed this transformer and put all your 120 volt single phase loads on the secondary of this transformer, and you can balance the load that way. You balance the secondary, you balance the primary. No high leg on the secondary, problem solved. There is an old saying in this business, "you throw enough money at a problem, it will go away."
I was speaking with a commercial electrician and he way telling me that 208y/120 3phase is very rare and 480 3 phase is more common. Maybe he just works on crazy large building only. But I know people that work on 208y/120 daily in my area, So it doesn't seem too rare
@davegordon6819 Dave, I absolutely enjoy your topics and teaching method. I have a question I’d love to see you do a video on. There’s a debate in the RV industry about the use of voltage stabilizers. Some say not to use them, as they will drop the voltage for the rest of the RV users, as the stabilizers sacrifice current for voltage, therefore pulling more current and lowering the voltage at the post. My take is that if there is low voltage at the RV post, say 104V, instead of 120 per leg, the appliances, Air Con, refrigerator, etc.,inside the RV are going to pull more current, as they maintain their power requirements. Therefore, boosting the voltage with an autoformer, will reduce current consumption at the RV, but will consume more current at the post, making the current equal to that without the autoformer, minus some inefficiencies. Am I off base here?
Dave I was wondering if you know where the term “single phase” comes from when referring to 2 legs of the 208 system connected to serve a load. I am constantly being asked why it isn’t referred to as 2 phase due to the fact that two of the phases are connected. I apologize if this is a silly question but I can’t seem to come up with a good answer. Anyway thank you for all the great videos!
At 2:20 you point with your finger the direction of current flow for the RED-half of the inductor. Is this correct or wrong? Appears to be a mistake. Are you using conventional current or electron current?
This man is a master at teaching... so clear. his body movements, his eye movements , hands all work in coordination with each other. his voice, easy on the ears... His brain the conductor of the whole operation. A pleasure to learn from...Thank you Dave.
Yes sir!! 🧑🏻🏫
Rolling my eyes
Dave taught at my JATC for a couple years. He’s literally the only reason about 40 of us made it past our second year.
I get the same vibe. This man knows how to teach well.
Sheesh .....get a room 😆
Truly a master in explaining, makes it easier to understand the concepts
Thank you, as a mechanical engineer I’ve always struggled with electrical concepts and this helped me understand much more about how the different windings affect voltage.
As a EE, I have to commend you on a well diagrammed and spoken lesson. Good job!
i feel lucky that people like dave are on youtube and shares their knowledge, great info!
I was so lucky to be in his classes. Dave, you rock, man.
Nice work Dave. This is one of the most thorough and understandable descriptions on 120/240 and 120/208....excellent.
Dave your videos are so immensely understated. You're an absolute hidden gem and I can't thank you enough for making this material available. I'm an IBEW electrician apprentice in my 3rd year and I constantly supplement my school work with your videos.
Excellent instruction, and a perfect example of how clarity doesn't require fancy animation, just a clear grasp of subject, words, and pictures.
Now for the love of all that's decent and proper, stop saying _"hot_ water heater", and change that "HW" to "WH". You don't need to heat hot water.
Thanks for your kind words and your attention to detail with "HW" and "WH". I will take note of this for future use as I have to agree fully with you.
Also, thanks for engaging with B YENZER1's comments as I have been unable to allocate much time to reviewing comments, but you will notice that I have added a somewhat lengthy comment to your last one.
p.s. By the way, since we're trying to be decent, proper, and particular with words, which phrase do you use? "I could care less" or "I couldn't care less"?
@@davegordon6819 - Well first of all, I never claimed to be decent and proper myself, so my phrasing is usually more colorful than either of those options. But I'm told by my neighbor who is an English prof and historian, that "I could care less" is the _older_ version of the two, contrary to common misconception. It was as if to say "You think I care very little now, well if you like, I can care even less." Only later did people misunderstand it as an error, and decide that it should be "couldn't care less".
@@pterafirma I've never heard that explanation so you (and your neighbor) have given me my new piece of knowledge for the day. Now I can go take a nap.
Thanks again.
Seriously, this guy has mastered the description of *why* 208v.
I'm about to start my second year of school and man am I glad I stumbled on your videos
Other than you kept referring to the peak voltages as 120V which would be confusing to a beginner when actually Vp ≈ 170Vac or Vp-p ≈ 340Vac hence the need for capacitors with 370V or 440V ratings.
Root Mean Square is just the DC equivalent hence there would be a straight line drawn through the sine wave to represent that average. Vrms = Vpeak/√(2). RMS is the only way to average a sine wave in case your wondering. It's also used to take an average in statistics to minimum the effects of outliers 😉
- 1st drawing - Single Phase
- 2nd drawing - Three Phase (Wye)
- 3rd drawing - Three Phase (Delta)
I suggest adding "Ugly's Electrical References" book to your toolbox because it covers all this and much more in case you forget.
Great video 😊
Dave, I was looking for the definition of a great teacher, and now I got it on this UA-cam video. You are beyond excellent and keep up doing this amazing teaching style.
You have simplified months of frustration in trying to understand these concepts. I cannot wait to check out the rest of your videos. I so appreciate the clarity you deliver. THANK YOU!
I'm blown away by your efficiency sir! All the little comments added explaining things for our green compadres shows how masterfully you teach. Thank you sir.
Searched for this explanation for way too long. Very well done Dave.
This man is a truly gifted teacher!!!!
He just schooled me so good!
Thanks sir
We love ur videos
His diagrams are perfectly simple
I liked this guy the moment he spoke. You can tell a great teacher within seconds. God bless S.T.E.M.
This is one of the best videos I have watched out of a lot out there that explains with this much clarity and expertise. Thanks for passing your knowledge how it should be with all.
this is literally the best explanation ive ever heard for this.
Sir, you're a teaching machine! You managed to master all your techniques magnificently. Thank you for that
Wow I wish I had a teacher like you when I was in trade school, nice job explaining and simplify something so complicated, please continue uploading videos!!!
Glad to hear someone use the correct definition of voltage. It is the "difference of potential" between two points.
Another EE here, and I like your teaching style, you dive just deep enough into the theory for the non-mathematically inclined to still understand the important concepts. It would be so easy to try and "prove" that you know the theory, but at the risk and expense of losing your audience, and that makes a poor instructor! You make it easy for those just beginning to learn the electrical trade to understand. Nice work!
The clearest instruction / explanation I have ever seen on this. Great video
I am electromechanical engineer, your explanation is very very clear. THANKS a lot teacher.
THANK YOU, I APPRECIATE YOU. Im literally sending this to few of my classmates and couple of my electrical friends
In Germany, the middle circuit is used, the Y circuit.
Transformer voltage from hot to neutral is 230V and from hot to hot it is 400V.
Wow you are amazing! Thank you so much for making this video. I will share this to all my friends.
Excellent teacher. I did electrical years ago and is the first I understood the topic.
Thank you, Dave! I've just discovered your videos while looking for some information about transformers. You combine two of my favorite subjects: electricity and math. Fifty years ago I was an electrician in the Navy. At that time, we were trained in single phase and three-phase delta and wye transformers. I understood it completely at the time, but never had experience with them since then and lost my knowledge of them. Now I understand them a whole lot better.
Thank you for a additional knowledge it's very important specially in my daily operations. Electrical lineman here in the phillipunes thanks a lot.
This man is really good he knows how to explain.He is a master keep it up
You are way better than any professor I know. I graduated with EE from college also.
Great people share their knowledge!!! God bless you!
This is the best explanation I have ever seen.
Fantastic video! I recently took over management of a 160 year old theatre that has a high leg delta panel in the projection room. Wanted to get familiar with the system. This video was incredible informative. Don't be worried. It did not give me the the confidence to monkey with the panel. I'll call a pro anytime this panel needs works.
Dude. This is awesome. Great way of explaining it. I totally get how this works, but being able to explain it is very hard for me and this way of explaining it is perfect.
I like the idea of the radius of a circle in terms of a generator, starting from west or zero axis , like a radar from west , north , east , south and to west. !
Radar or radius is from center point to the inner circumference of the circle ⭕️ . Diameter is from west to east or north to south, that is why a radius really is interesting like radar !
I've been digging to find a good explanation and now I've found it. Thank you sir!
Well done. And I actually saw the fireworks first hand at work when one of the guys installed a bunch of new 120 V fluorescent fixtures to a 208V high leg by mistake. WE also had 277 VOLT stuff that people made mistakes with. Luckily we worked for BIG OIL. They could afford it.
The 120/240V thing was actually a late 19th century thing - all derived from the Great Fire of Chicago. Edison lamps were made out of carbon, and used 110V, however, other companies figured out how to make lamps using tungsten, a much more resilient metal and could work at 240V (carbon lamps burn up at 240V). Since adoption of electricity was much slower in Europe, the European utilities went with 240V as it saved money on copper and is more efficient. Our 110V system was derived as a split-phase system, because Edison noticed that some people's lights were brighter than others. So he designed the system as two 110V generators (this was DC, mind you) and connected them together to form a third neutral line. He realized by monitoring the current flowing on the neutral line, he could determine how bad the imbalance was and rebalance the grid so the same number of lamps were on each half so everyone's lights were the same brightness. In addition, if you needed more power, you had 240V (DC) available.
Now, electrification was huge in the US - especially after the Great Fire of Chicago which meant everyone started from scratch, and skyscrapers were a thing. Gas lamps couldn't be lit more than a few stories up, and everyone wanted electric lighting. So much so that demand for light builbs was so big even though carbon lamps were obsolete, Edison was still making millions of them as the tungsten lamp makers couldn't keep up (in the late 19th century, they made around 10 million tungsten lamps, and Edison made nearly 60M carbon lamps. This changed about 20 years later in the early 20th century when carbon lamps were finally obsolete and replaced with tungsten lamps. However, by now the die has been cast - 110V had been around for so long, there was no appetite to change over to 240V..
In Europe, electric lamps were seen as a novelty, and very few people had it. The rich folks refused to install it in their castles, so when it came time, it was trivial to switch over.
Oh, and the first war of the currents was between Edison and Westinghouse, not Tesla. The second war of the currents was between GE and Westinghouse which dictated if we'd use two-phase (Westinghouse, via Tesla's patents) or three-phase (GE, Edison had been kicked out) AC. Tesla is confused in these because Westinghouse bought Tesla's AC motor patent (and later all of Tesla's patents). That patent showed how a motor would work at 60Hz two-phase. You have to remember though, that just because of this, power was still not quite standardized as you could get DC, 60Hz, or 133Hz AC power (133Hz because Westinghouse managed to find a design for an electric meter but that required 133Hz to run properly).
133Hz from my understanding, was more commonly used with carbon arc lamps common for streetlights and in factories and large retail stores from the early 1880s until the early 1900s, because it flickered less than 60Hz. You also had very oddball frequencies such as 25, 33.3 & 40Hz, to name a few. The early days of electrification must have been a very intriguing time to live through. And all this was in major US cities, many farms and homes in rural areas didn't have electricity until after WWII, my grandmother recalled not having electricity until merely a few months before she married in 1947, born in a farmhouse in 1925 and lived to be 96.
Amazing explanation!
I like the way you teach this topic. Thanks for sharing knowledge.
Best explanation ever. I finally understand!!!!!!!!!!
Thank you.
Thank You Dave well done! Best teacher I seen yet! Thanks again.
Excellent video!!!! For the case of the delta transformer. As we can determine the current in each winding to determine the single-phase and three-phase load distribution in them and thus their optimal size, this in the case of being a bank of transformers.
Wonderful info, thoughtfully and clearly laid out
Excellent presentation Dave, was a joy to learn from ya
Great video, I do have one question at 10:25 when you said that if you take any vertical point on the 3 phase graph and add it up you get 0. Are you referring to where the one phase peaks and the other 2 phases are intercepting underneath that peak? I assume you are subtracting the value of the peak from the values of the negative voltage phases underneath the neutral. Just threw me off when I heard you say that.
Thank you so much for your crispy clear explanation! This helped me so much, awesome!
Absolutely immaculate explanation
Excellent video that explained some of the lingering questions I had regarding electrotechnology. Thankyou Dave!
While 208 volts is a 3 phase voltage produced by 3 phase transformer bank, it is commonly used as a network voltage by utilities as a leg to leg voltage for single phase residential loads instead of 240.
So is it safe to use the 208v along with with neutral or earth?
"Hot water heater". (snicker, chortle, guffaw). Perfect lesson, yet again.
You answer the question that I been looking for I don’t know how long
Yes, the center tap of the secondary winding (neutral to ground) is both positive and neutral (at the same and time)
Stupid question time. Are the line 280 wires Brown, Orange Yellow and the black, red and blue the outputs? Would you be running the Neutral for 120v in white? You probably have a wire color code video, I'll look. You do amazing videos. Some airhead talks about stringing beads and gets 100K subscribers, but real , well presented videos don't. Life isn't fair. Thank you for taking the time, the videos are great.
I like this channel. It's for smart people.
You may cover this in another video, but there is another reason to have a 240 delta system. If you already have a 120/208 Y system in your facility and need another service,NEC says the second service must be a different voltage, hence have a 120/208Y service and a 120/240 Delta service on the same building.
Thank you Dave, easily explains the differences as well as applications. And thank you for the math lesson (brings back memories).
My God I needed this refreshing course I'm am definitely enlightened
Amazing explanation, very good job 👏
what a master class. an absolute pleasure to see it
Very good explanation. Crystal clear tome
Wow, this was super helpful. Thanks for posting this.
Thanks from Austria for the teaching - work. 🙏
You're a very good teacher. I've been trying to find someone to explain this to me for awhile now, searching all over UA-cam and the internet in general and haven't found a single person that can explain this in a manner that I could understand until I seen this video. I appreciate that you took the time to make this. Thank you.
fantastic job explaining this topic
In my country the voltage between the phase and the neutral conductor is 230V +/- 10% and between any two phases it is 400V. Every other house has a three-phase connection.
Thank you for helping me understand the wye out of phase 208 and the delta ! My teacher could use some lessons from you on explaining things better!
In case I wanted to connect a single phase load on 208V, the two wires I have to choose from can be any live combination that is from the three live wires, What I do not get and I want clarity on is if am choosing any two wires from these three for single phase connection, how do I incorporate the neutral? Because here in Canada we use Black, White and Green for any single phase load. When you say 208V single phase around 8:45 minutes, how do i do the arrangement so that I incorporate my live wire, a neutral and a ground?
Here in canada, we dont have single phase 208V ( line-neutral ).
Its like he explains, ( Line to Line ) is 208v
And ( Line to Neutral ) is 120v
The colors of your wires dont matter.
You can always put some red tape on your white wire if it not a neutral, just to prevent mistakes or accidents.. but if its clearly identified as 208v, usually, nobody will think that the white wire is neutral.
Thanks for explaining a different method to calculate the HIGH LEG to ground. I did not know using Pythagorean theorem gives you 208AVC. I've always use Vector addition.
Excellent teacher! That was great explanation, made it look so simple even though it ain’t. 👍👍👍
Truly outstanding lesson. Thank you.
There are plenty of uses for the high leg. Many modern LED light fixtures are rated for voltages between 100 and 277 volts 50 or 60 Hz. If you use the high leg, make sure that you use a straight rated 240 volt breaker.
So you're saying there are single pole, straight 240V breakers manufacturered ??? If so they're about as rare as a royal flush.
@@Sparky-ww5re No, but all 3 pole breakers are straight rated and some double pole breakers are. You can simply use the high leg as part of a multi wire branch circuit. There's nothing in the NEC that says you can't use the high leg to neutral. You can run three (2 wire) branch circuits from a three pole breaker. You can not however run a 4 wire branch circuit with a shared neutral from three single pole breakers. NEC 210.4B.
Great teaching skills. You making it very easy to follow. Thank You 🙏🏼
Your explanations are clear
Very Informative! Easy to follow!
I did the HW chum
rms = root means square
center neutral opposing and pushing relativity of product
Bus wiring
Voltage = Points if differential potential of to points (Check out angle theta!!)
as well as from which 120 degrees of the exact moment of the circuit became energized comparing the constant peaks per delegated cycle (Alternating Current and it's Value) while subbing out impedance with greater use of Volts and VA (Volt Ampere) to mediate or use the Load (What the conductors are connected two and their rating) for treatment of the new simulated
resistance from use of Center Tapped Neutral
Connecting within the center if the Wye Connect will split...not only the windings but the voltage.
Equaling=B phase To High leg is 208V
Make Sure You label!
Very good explanation/tutorial. Thank you for sharing.
Clearly explained. Really helped what i was looking for
10:54
I'm an electrician, and never understanded why the neutral ( X0 ) has to be " grounded " ?!
I know what happens when it's not, but dont understand the reason...
Is it only in case of unbalanced 120v loads in a star 120/208v ?
But what if its 3 phases 208v star configuration, and we only put a load on phase A and B ( 208v single phase ) , and the X0 is not grounded, what happens?
Excellent explanation
Awesome job of explaining 120/240 and 120/208 theory 👍
Question: Where would a wye transformer like this one be used? It seems like the only place it would be good for would be structures requiring only 120V services. Are there any instances where straight hot leg to hot leg 208V would be needed? Aren't most devices 120V or straight 240V? I understand 3 phase where you have a high 208V leg, but I've never seen that high leg used on a single pole by itself, it's always used in conjunction with the other 2 phases to produce +240V at 3 points during the cycle.
For this single phase connection at 8:45 minutes, do I need a neutral? Or just the 2 live wires? It isnt so esy to comprehend
Thanks a lot Mr. dave, I just need some more clarity around 8:45 minutes, it does not cut across that easily.
My favorite term for the high leg of a delta transformer for 120/240 is the "bastard leg."
another system worth an honorable mention, is, an open delta, typically 120/240, but occasionally corner grounded 240. I've seen this in rual areas, almost always on a farm setting, when most of the loads are single phase 120/240, with a smaller amount of 3 phase motors, typically a grain drier, augers and conveyer. The capacity of a full delta is not warranted, and the system can be easily recognized, by the two transformers, one being significantly larger, in terms of KVA, because all your 120V loads come off that one. the smaller transformer is the power transformer, this provide the high leg. Much like the full delta, open delta suffers from the same limitations, very difficult if not impossible to balance, along with the possibility of mistakenly connecting a single pole breaker to the high leg when 120 volts is needed. As such these systems are rarely encountered in new installations.
I was wondering if someone would spot this. I actually did a job at a water treatment plant in Pueblo, Colorado that used an open delta service.
You are just awesome! Thank you👍
The high leg delta system although very seldom used in new installations, actually is a really cool system. Although all electricians know and probably have worked with the 120/208/240 delta at least a handful of times in their career, there is also yet another delta that is extremely rare and many electricians will never come across it, some may not even know it existed, but it's a 240/415/480 volt delta.
Very interesting
I prefer it to the 208Y/120 volt system, otherwise known as the wimpy Wye.
@@jolyonwelsh9834 for me it depends on the application. If I have a lot of single phase and three phase loads, I prefer the 208Y/120, as it's easier to balance the loads, and eliminates the chances that someone will accidentally connect the stinger leg 208V to a 120 volt circuit and burn up equipment, it's happened more frequently than an honest electrician would care to admit. Where I hate the wye system is in apartments and hotels with a kitchenette, the range tests my patients when I need to boil a pot of water (I hate electric ranges anyways, I'll take on gas anytime day or night) and clothes take longer to dry.
If I have a bunch of three phase motors, with a smaller amount of 120 volt loads, I like the 120/240, 3 phase 4 wire delta better.
@@Sparky-ww5re There's a more expensive but thorough solution. Maddox brand transformers manufacturers a 3 phase transformer with a 240 volt delta primary and a 208Y/120 volt secondary. Have a 3 pole breaker to feed this transformer and put all your 120 volt single phase loads on the secondary of this transformer, and you can balance the load that way. You balance the secondary, you balance the primary. No high leg on the secondary, problem solved. There is an old saying in this business, "you throw enough money at a problem, it will go away."
I was speaking with a commercial electrician and he way telling me that 208y/120 3phase is very rare and 480 3 phase is more common. Maybe he just works on crazy large building only. But I know people that work on 208y/120 daily in my area, So it doesn't seem too rare
Awesome job explaining
Thank you for excellent lesson
So in the “Y” system you can touch the neutral (like in a splitter) because it’s grounded and not get shocked
Good teacher. Love it!!
@davegordon6819
Dave, I absolutely enjoy your topics and teaching method.
I have a question I’d love to see you do a video on.
There’s a debate in the RV industry about the use of voltage stabilizers. Some say not to use them, as they will drop the voltage for the rest of the RV users, as the stabilizers sacrifice current for voltage, therefore pulling more current and lowering the voltage at the post.
My take is that if there is low voltage at the RV post, say 104V, instead of 120 per leg, the appliances, Air Con, refrigerator, etc.,inside the RV are going to pull more current, as they maintain their power requirements. Therefore, boosting the voltage with an autoformer, will reduce current consumption at the RV, but will consume more current at the post, making the current equal to that without the autoformer, minus some inefficiencies. Am I off base here?
Dave I was wondering if you know where the term “single phase” comes from when referring to 2 legs of the 208 system connected to serve a load. I am constantly being asked why it isn’t referred to as 2 phase due to the fact that two of the phases are connected. I apologize if this is a silly question but I can’t seem to come up with a good answer.
Anyway thank you for all the great videos!
Do you have any videos on how secondary rotation is affected by the primary connection? Specifically on 2 pot banks.
At 2:20 you point with your finger the direction of current flow for the RED-half of the inductor. Is this correct or wrong? Appears to be a mistake. Are you using conventional current or electron current?
Thank you for teaching.