One of the best videos I've seen on this topic so far. This is first time I've had someone verbally explain this topic in such a way that it was easy to grasp just with words, without having to rely on constant illustrations or animations. Very good job
Hey, not bad; ordinarily when engineers speak my mind automatically goes blank, but electrical engineers; it goes blank to an Abba sound track. Your instruction was good, being a big fan of the Tesla vs. Edison controversy back I like the fact you gave Tesla his due. Tim keep them coming I am actually learning something.
Thanks for the feedback John. If you visit Niagara Falls there are a few statues of Tesla, sadly I have asked people walking by if they knew about Tesla and they only know about the car company. They also don't know that Niagara Falls was one of the first experiments at large scale power generation and transmission to Buffalo for the 1901 Pan-Am Expo, one of the first large scale event that used electric lights.
Hey, I don't have much words to express myself about your explanation but please do consider this that your explanation was infinite times above awesome. Thanks for it and i learned a lot.
I am just getting started in the electrical industry as an estimator/project manager. This video was very practical and useful. I am glad you used some simple terminology/examples to explain very dense topics. I appreciate you taking the time in making this video.
Great start to the series on power. You have a knack for explaining these things in an easy to understand format, good job. I have known this stuff for sixty years and am still watching it, it's entertaining to see how you approach the material and so far putting myself in the place of someone who did not know this material or who just didn't quite get the concepts explained to where they could understand it you are doing a great job. I think your series will be of great help to those folks in understanding these complex yet fundamentally simple concepts. An excellent start, good work.
Thanks again John, greatly appreciate the feedback, cool that you find it interesting even though you are familiar with the topic. I need to make 1 or 2 more fundamental videos and then I think we will start with stepper motors as they are the most widely used by hobbyists. Next videos will be volts, amps, resistance, capacitance, and inductance.
Add-on: Every wire has some resistance. Using longer wires increase resistance of the wires and resistance will translated to heat. A thin wire can easily transport a (high) voltage however cannot provide a high current = low power. If you provide high current it will evaporate immediately. To transport current requires thicker wires to lower the resistance in the wires. So if you want to transport power, it is more efficient to use a high voltage and a low current, instead of a low voltage and a high current because a low voltage and high current requires more copper to transmit the same amount power. A high current in combination with the resistance of the wires produces more heat = power loss and because of the power loss it will introduce a (higher) voltage drop at the end of the wire. With a low voltage and high current you need more power to get the same amount of power at the end of the wire. A great benefit of AC is reduced heat generation in wires (take a look at Tesla and Edison made examples), current go in both directions and isn't constant (sine) like DC. To transport DC you need thicker wires = more copper. High voltage AC can transport more power with less amount of copper than high voltage DC can do. Low voltage DC (24VDC for example) requires very thick wires to transport the same amount of power and keep wire resistance as low as possible to transport high currents and to avoid the cables heat up too much. That is why car starter cables are very thick cables to be able to handle the high currents at 12VDC. That is why AC cables (120-240VAC) in buildings can be pretty thin. Remember that power consumption is not the same as the power output, it depends on many factors and there is always a conversion loss to convert electrical power into (for example) mechanical power. The same with an amplifier for example, if the amplifier outputs 200W it doesn't mean that you will get 200W of music power with any speaker. The effeciency or sensitivity of the speaker is very important to translate all of the power into something useful. The same with motors. Sorry for the long post. Hopefully somebody will read this. ;-)
Cool video. Boost Converter can boost DC. lol. MOSFET Gate on/off/on/off PWM, connected to diode > inductor (coil of wire) > capacitor. Honestly didn't really grasp how or why AC was better.. but now I realize that transformers are just two wraps of wire. I got it now. Thanks, cool video.
This video is AWESOME! Thanks so much for taking the time to make it and explain it so clearly :D I've just taken over my families farm and am installing three phase into the barn and this really helped me understand everything electric so much more. I'll be able to ring up electricians and get quotes now and have a basic understanding of what they're doing. This sort of thing really makes me love the internet :D Woooop!
Perfect example of DC power ***starts AC motor*** Perfect example of AC power ***starts DC motor*** :) I kid. It makes perfect sense. Just a bit of irony. (And yes, the DC motor is commutated to no longer truly be DC...)
Hi Tim. Been an engineer for 45+ years. Would have got better grades if you were my teacher way back when!! Your style is so refreshing and interesting even though I know this stuff backwards! Well done. So looking forward to getting into the control circuits (cards) explanations etc as they pertain to cnc machines. Only problem is I would love to be able to afford a"proper" cnc machine like your Fadal. In the meantime, relying on my old Bridgeport on Mach3 and dc servos! Keep up the good work.
Thanks Bernard, I was not aware I was teaching any different, just having fun. Going to take a while to get to controls, but we will get there. I understand a lot of people know the fundamentals but a lot of people do not, so we need to make sure everyone has a basic understanding before we start diving in. There is nothing wrong with a Bridgeport and Mach3, it gets the job done! Even my machine is using DC servos and they work just fine.
if you can't explain it simply, you don't understand it well enough. You sir explained these concepts very well. 3rd year elec engr student and I don't have a strong grasp on this concept until after this video. Thank you.
Wow, Absolutely fantastic, I'm a generator mechanic in the ARMY and stumbled on your video trying to gain a better understanding. Recently had a 3 phase AC unit with a 4 wire pigtail, figured it out through the schematics. Ground, L1,L2,L3 struggling to understand why neutral was not necessary. Any words of wisdom would be greatly appreciated.
Hello Adam, 3 phase systems can be connected two ways, "Delta" and "Wye". In the Delta configuration there is no neutral and all current flows between the legs. The connections are made so that each load or source forms a triangle. So there is a load between L1 and L2, then L2 and L3 , last L3 and L1. The Wye connection looks like, well a "Y" where one side of each load is connected to one of the 3 legs, then the other side of the loads are connected together to make a single point in the center. This is considered the "Neutral" in the system. In the Wye configuration, if all loads are perfectly balanced there is zero current flow through the neutral. Only when the loads become unbalanced will there be current flowing in the neutral. Each configuration has there pro's and con's. Hope that helps, maybe a video on this topic as well.
You sir rock!! That is the best explanation I have heard/seen. It is easy to learn with the way you explain and I enjoyed the video thoroughly. Thanks!!
nice analogy with the band saw, and recip saw, never thought of that one before, and always looking for good analogies for explaining concepts to people
Thank you, electricity is a hard topic because you can't see it. Only easy way I found to teach it is by relating it to something people can see and already know.
Stellar explanation of One phase and three phase power! I really liked your incorporation of induction motors. You need to be teaching in a college classroom.
What a Teacher Tim !, Great stuff, I came here looking for a Fadal query but just enjoyed watching this, your talent is waisted sir ! I'll gte to my Fadal search now. Ragards, Steve
There were some systems built early on that ran on 2 phase power in the Niagara Falls area. I've seen photos of Monarch lathes with 2 phase motors. As you pointed out, 3 phase is in the Goldie Locks zone for all around use and rapidly supplanted other proposed transmission systems and power equipment. Of course the bane of home shops is the unavailability 3 phase and the hoops you have to jump through to either modify industrial motors to hobble by on single phase or by some method generate 3 phase power. Both options obliterate any performance gain that 3 phase offers. The only saving grace is the limited amount of time that equipment is usually run in the home shop.
You are correct, there was such a thing called "2 phase" power. But it was totally different then the split phase power in your home that some people confuse as being 2 phase. Real 2 phase power used 4 wires in most cases and sometimes used 3 wires with one conductor being larger then the other 2. That was the main issue why 3 phase won out over 2 phase. You could transmit the same amount of power using 3/4 the amount of wire. The reason they tried 2 phase was mainly for motor starting. Each phase was 90 degrees apart which gave a sin/cos wave. The other reason was the calculations for loads and such; back then no one had figured out how to calculate for 3 phase unbalanced loads. So it was easier to do the math on just a 2 phase system. I don't know why it is so hard to get 3 phase power into a home shop. If its on the pole and your willing to pay for the installation costs what is the big deal?
My experience is that the installation cost is so high that even for a commercial operation job shop that's not in an industrial area, buying a rotary phase converter is often the most economical way out. The power company certainly doesn't make it easy.
It depends on your area, if you have 3 phase at the pole and it only needs one transformer to step it down then the cost is not that bad. If you don't have 3 phase at the pole, which a lot of residential and rural areas don't, then they can not justify the cost with only one customer. Power companies hate phase converters, causes imbalances on the 3 phase grid. 3 phase power really does not like to have imbalances.
The power company typically will not install it in a residence. If you have a shop, and there is 3 phase on the pole, SOME places will give you a service to the shop. My power company gave me the run around to no end, so I gave up. My machine is still small enough it can run on single phase without to big of an issue.
@@AtManUnlimitedMachining The irony: the reciprocating saw runs on a DC motor, and the band saw runs on an AC motor. Of course, it is what the mechanical machine is doing that is the analogy for the two forms of power, rather than what the motor is doing.
We standardized on AC because technology didn't exist to use DC 120 years ago. You are now seeing more and more DC used for transmission in parts of the world that don't have the infrastructure built out (also in some countries that are more open to change). Good example are the Three Gorges Dam in China, underwater transmission lines and some parts of Europe. Why are they using what is called high-voltage, direct current (HVDC), because the costs are now lower and you have lower electrical losses than AC, technology has changed. We will probably never move to it here because at some point in the distant future localized power generation like solar or wind will happen (just like we will move all to metric some day but probably not in my lifetime, but it will happen).
Yes, there are and have been some DC transmission systems. But I'm not sure DC will ever over take AC for the bulk of transmission. Reliability and overload capacity are two huge factors for large power distribution systems. You just can't get more reliable then a simple coil of wire. AC transformers also have huge short duration overload capability, not so with DC converters. DC is only being used in a few very specific applications. Underwater power transmission as you mentioned is one of them. This is due to the underwater cable having significant more capacitance then just bare wires hanging from a pole. The capacitance of the wire consumes a lot of reactive power as the current flow changes directions. Maybe some day DC will have its day, but I don't think it will be any time soon with today's silicon.
Hello Drew, if we are talking about 3 phase power there are two connection types. The first is Delta, in this case the load is connected to the 3 phases in a triangle. There is no neutral, only 3 phases and a ground, 4 wires total. The second is called Wye, here the load is connected like, well, a Y. The load is connected to 3 phases on one side and then center connected to form a neutral. There are 5 wires total, 3 phases, 1 neutral, and a ground. Note that with a Wye connection and a balanced load there will be no current flowing through the neutral. Current will only flow through the neutral if there is an unbalanced load. Hope that helps Tim
Thank you best explanation on for on single and three-phase question, I'm going to do a little experiment and build a Pelton hydroelectric generator if I use a 3-phase motor will I be able to run tools from my shop on it?
If you can make enough power and keep the voltage and frequency stable you should be able to. I would do the math to figure out if you have enough water to generate the amount of power you need, taking into account for the systems inefficiencies.
Yeah I'm going to try an experiment like a recirculating type of system with a solar-powered pump. I don't even know if it's possible but I like to try things just something like this sound feasible to you?
I would make sure to be extra careful in doing some math first. You are going to have a lot of inefficiencies with a system like that. You are probably going to lose 50% of the solar system capacity in losses.
In a 3 phase system all phases should be balanced. Having a phase imbalance can cause many issues for equipment and the power company. If your using a rotary phase converter the one phase that comes from your utility will be the "strongest". You may see voltage differences using a phase converter. The generated phases wont be as stiff as the utility, meaning you will see much higher voltage drop under heavy loads.
2 phases are also can be used! but 3 are better. at 2 you need also 3 and have less good condition! and there is one large mistake! if the rotor of an induktion motor are a magnet by itself you create a synchronus motor! thats is not a induktion motor any more even if the outer part the stator is the same in many cases!
Hello, I don't think you will ever see a true 2 phase system in practice today. I have never seen one in use my self anywhere. Many people confuse the standard home electrical service in the US as a "2 Phase" system when in fact it is a single phase split system. Yes, if the rotor of a motor is a permanent magnet it is a synchronous type motor. This video was more of a discussion about power and not really motors yet, many people have the basic concept of a magnet in a motor rather then a squirrel cage. I will be doing in depth videos on motor types.
it was just an old idea and some enginers like the idea ! but he also say you have some good points in saving switches and fuses but thats all. on the other side there are some bad points
If a building has 208V 3 phase 4 wire, would it be an issue to install a 240V outlet for a machine that is rated for 2500W and 12amp draw? I was told by an electrician that is somehow a big deal and came here to learn for myself... I cannot see how it is an issue since 208V is 3 phases of 120V. I would appreciate any help!
I would not consider it a "big deal", but it is not as simple as adding an outlet and breaker. You will need to buy a step up or boost transformer to take the 208 and step it up to 240V. You can do this for a single phase or 3 phase load. You don't need a huge transformer, make sure to do proper calculations for sizing.
At-Man Unlimited Machining If you dont mind, could you explain for me how it is not as simple as adding a 240v outlet? Why is it an issue to draw 240v if 208v is 3 phases of 120V? I didn't know anything about electrics except for the formula W=I*V learned in school. Just starting to review and the basics now.
240V is a voltage seen in residential homes, it is single phase. In your house you have 3 wires coming in, two "hot" and one "neutral" If you measure the voltage from "hot" to the other "hot" you get 240V. If you measure from "hot" to "neutral" you get 120V, or half of 240. If you look at each 120V "leg" on an oscilloscope you would see there 180 degrees out of phase. So when one is at peak, the other is at valley and you get 240V. Now lets talk about commercial power, it is not single phase, but is now 3 phase. The original poster has 3 phase 4 wire system (actually 5 if you add the ground). In this case you have 3 "hot" lines and one "neutral". If you measure between any of the "hot" lines and the "neutral" you will again get 120V. However, if you measure between any two of the "hot" lines you will only get 208 volts, not 240. The reason is because unlike the residential single phase power that is 180 degrees out of phase, the 3 phase system in commercial is 120 degrees out of phase. So when one "hot" line is at peak the other "hot" lines are not at there valley, which results is seeing a lower voltage. If you use a voltage with a device that is lower then its design voltage, it will need to draw more current to use the same amount of power, that is your W=I*V equation. More current means more restive losses in the device and more internal heating, not good for the device. In these cases, you use a step up transformer to step the 208V up to 240V so the device runs at the correct design voltage. Many devices, like welders and some machines will have different "taps" on them to operate at 240V or 208V so they can be used on single phase or 3 phase power systems. Hope that helps, Tim
DC is needed for electronics. Many of the silicone devices need DC power for various reasons. Variable speed drives also need AC at various frequencies and the more efficient way to do that is by using electronics to make a DC bus and then again converting back to AC at a controllable frequency.
That is a complex answer, like many things it is a compromise. 50/60 Hz was not the standard at first. The Niagara power project first used 25 Hz. This worked well for transmission and for the motors of the time, but light bulbs would have a noticeable flicker to them. They also used 40 Hz and some tried 133 Hz. Aircraft use 400 Hz systems. It is a balance between transmission losses and equipment size mainly. 60 Hz has an acceptable amount of transmission losses, while allowing for the reduction in the size of transformers and motors. Lower frequencies would yield lower transmission losses but require more iron and copper for every transformer. The opposite for higher frequencies. Aircraft use high frequencies because they are not transmitting the power very far and really need to save weight, so they use 400 Hz.
@@AtManUnlimitedMachining i see now,power losses is main problem for higher frequencies,i think it is similar with DC problem about power losses due the transmision am i right?
The issue is more complex then that. If you look at what causes the losses for DC power in a wire, it is purely restive in nature. However, with AC, the losses are from the impedance of the wire, which takes into account the capacitance and inductance of the wire with its resistance and the frequency. The main reason AC is used is conversion. You only need two coils of wire and you can step up the voltage of an AC system very cheap and easy. The higher the voltage, the lower the current given the same amount of power. Lower the current, you get less losses from heating up the wire. Most power is transmitted today well over 100,000 volts with lines as high as 1,000,000 volts being built. There are DC power transmission lines today, but the technology did not become viable until about the 1960's to convert and handle that high of DC voltage.
One of the best videos I've seen on this topic so far. This is first time I've had someone verbally explain this topic in such a way that it was easy to grasp just with words, without having to rely on constant illustrations or animations. Very good job
Hey, not bad; ordinarily when engineers speak my mind automatically goes blank, but electrical engineers; it goes blank to an Abba sound track. Your instruction was good, being a big fan of the Tesla vs. Edison controversy back I like the fact you gave Tesla his due. Tim keep them coming I am actually learning something.
Thanks for the feedback John. If you visit Niagara Falls there are a few statues of Tesla, sadly I have asked people walking by if they knew about Tesla and they only know about the car company. They also don't know that Niagara Falls was one of the first experiments at large scale power generation and transmission to Buffalo for the 1901 Pan-Am Expo, one of the first large scale event that used electric lights.
This guy is a natural, one of the few on CZcams who has a genuine understanding of what his talking about.. subscribed
Thanks Kevin, appreciate that! But lets not get carried away here, I'm just another schmuck in a garage you know ;)
At-Man Unlimited Machining
Thanks for the reply, much appreciated. Best of luck with your channel
Thank you!
That was a very good explanation regarding phases.
Thank you
Hey, I don't have much words to express myself about your explanation but please do consider this that your explanation was infinite times above awesome. Thanks for it and i learned a lot.
Thank you
I am just getting started in the electrical industry as an estimator/project manager. This video was very practical and useful. I am glad you used some simple terminology/examples to explain very dense topics. I appreciate you taking the time in making this video.
Thanks for the feedback Mike
Thank you sir ... It's great to have people like you in youtube .. ☺
Finally someone was able to explain it the right way
Thank you Tim, great explanation as the usual!
Your Welcome, glad you liked it :)
Great start to the series on power. You have a knack for explaining these things in an easy to understand format, good job. I have known this stuff for sixty years and am still watching it, it's entertaining to see how you approach the material and so far putting myself in the place of someone who did not know this material or who just didn't quite get the concepts explained to where they could understand it you are doing a great job. I think your series will be of great help to those folks in understanding these complex yet fundamentally simple concepts.
An excellent start, good work.
Thanks again John, greatly appreciate the feedback, cool that you find it interesting even though you are familiar with the topic. I need to make 1 or 2 more fundamental videos and then I think we will start with stepper motors as they are the most widely used by hobbyists. Next videos will be volts, amps, resistance, capacitance, and inductance.
Add-on: Every wire has some resistance. Using longer wires increase resistance of the wires and resistance will translated to heat. A thin wire can easily transport a (high) voltage however cannot provide a high current = low power. If you provide high current it will evaporate immediately. To transport current requires thicker wires to lower the resistance in the wires. So if you want to transport power, it is more efficient to use a high voltage and a low current, instead of a low voltage and a high current because a low voltage and high current requires more copper to transmit the same amount power. A high current in combination with the resistance of the wires produces more heat = power loss and because of the power loss it will introduce a (higher) voltage drop at the end of the wire. With a low voltage and high current you need more power to get the same amount of power at the end of the wire.
A great benefit of AC is reduced heat generation in wires (take a look at Tesla and Edison made examples), current go in both directions and isn't constant (sine) like DC. To transport DC you need thicker wires = more copper. High voltage AC can transport more power with less amount of copper than high voltage DC can do. Low voltage DC (24VDC for example) requires very thick wires to transport the same amount of power and keep wire resistance as low as possible to transport high currents and to avoid the cables heat up too much. That is why car starter cables are very thick cables to be able to handle the high currents at 12VDC. That is why AC cables (120-240VAC) in buildings can be pretty thin.
Remember that power consumption is not the same as the power output, it depends on many factors and there is always a conversion loss to convert electrical power into (for example) mechanical power. The same with an amplifier for example, if the amplifier outputs 200W it doesn't mean that you will get 200W of music power with any speaker. The effeciency or sensitivity of the speaker is very important to translate all of the power into something useful. The same with motors.
Sorry for the long post. Hopefully somebody will read this. ;-)
Cool video. Boost Converter can boost DC. lol. MOSFET Gate on/off/on/off PWM, connected to diode > inductor (coil of wire) > capacitor. Honestly didn't really grasp how or why AC was better.. but now I realize that transformers are just two wraps of wire. I got it now. Thanks, cool video.
Very very clear
Perfect teacher
Thank you
Thanks for sharing Tim. Really great job on this video. Looking forward to the next one.
Thank you Stephen
Awesome video! I'm going to school for hvac, and the book didn't quite break it down for me enough. Thank you!
Welcome, I have a few friends in HVAC, good line of work.
it was a really great explanation man, bold and firm, thank you !
Welcome
This video is AWESOME! Thanks so much for taking the time to make it and explain it so clearly :D I've just taken over my families farm and am installing three phase into the barn and this really helped me understand everything electric so much more. I'll be able to ring up electricians and get quotes now and have a basic understanding of what they're doing. This sort of thing really makes me love the internet :D Woooop!
Thanks for the feedback, happy to help!
Good clear presentation which helped me grasp some basic concepts which I never received watching some other presentations. You're a good teacher.
Thank you
Perfect example of DC power ***starts AC motor***
Perfect example of AC power ***starts DC motor***
:) I kid. It makes perfect sense. Just a bit of irony. (And yes, the DC motor is commutated to no longer truly be DC...)
Very methodical, clear, and concise! Love it! Thank you!
Thanks!
Excellent video. This gave me a better understanding of 3-phase wiring
Thank you
The electricity meter measures energy - kilowatt-hours. Energy is power integrated over time.
Hi Tim. Been an engineer for 45+ years. Would have got better grades if you were my teacher way back when!! Your style is so refreshing and interesting even though I know this stuff backwards! Well done. So looking forward to getting into the control circuits (cards) explanations etc as they pertain to cnc machines. Only problem is I would love to be able to afford a"proper" cnc machine like your Fadal. In the meantime, relying on my old Bridgeport on Mach3 and dc servos! Keep up the good work.
Thanks Bernard, I was not aware I was teaching any different, just having fun. Going to take a while to get to controls, but we will get there. I understand a lot of people know the fundamentals but a lot of people do not, so we need to make sure everyone has a basic understanding before we start diving in. There is nothing wrong with a Bridgeport and Mach3, it gets the job done! Even my machine is using DC servos and they work just fine.
Well, that cleared that up. Thank you.
if you can't explain it simply, you don't understand it well enough. You sir explained these concepts very well. 3rd year elec engr student and I don't have a strong grasp on this concept until after this video. Thank you.
Welcome, been doing it for a while now.
Wow, Absolutely fantastic, I'm a generator mechanic in the ARMY and stumbled on your video trying to gain a better understanding. Recently had a 3 phase AC unit with a 4 wire pigtail, figured it out through the schematics. Ground, L1,L2,L3 struggling to understand why neutral was not necessary. Any words of wisdom would be greatly appreciated.
Hello Adam, 3 phase systems can be connected two ways, "Delta" and "Wye". In the Delta configuration there is no neutral and all current flows between the legs. The connections are made so that each load or source forms a triangle. So there is a load between L1 and L2, then L2 and L3 , last L3 and L1. The Wye connection looks like, well a "Y" where one side of each load is connected to one of the 3 legs, then the other side of the loads are connected together to make a single point in the center. This is considered the "Neutral" in the system. In the Wye configuration, if all loads are perfectly balanced there is zero current flow through the neutral. Only when the loads become unbalanced will there be current flowing in the neutral. Each configuration has there pro's and con's. Hope that helps, maybe a video on this topic as well.
Brilliant video! Thank you.
You sir rock!! That is the best explanation I have heard/seen. It is easy to learn with the way you explain and I enjoyed the video thoroughly. Thanks!!
Thank you, there will be more coming at some point!
nice analogy with the band saw, and recip saw, never thought of that one before, and always looking for good analogies for explaining concepts to people
Thank you, electricity is a hard topic because you can't see it. Only easy way I found to teach it is by relating it to something people can see and already know.
Thank you very much, I finally understand the power a little bit.
Stellar explanation of One phase and three phase power! I really liked your incorporation of induction motors. You need to be teaching in a college classroom.
Thank you, but I really enjoy being in the thick of things. I do teach professional learning type classes sometimes.
What a Teacher Tim !, Great stuff, I came here looking for a Fadal query but just enjoyed watching this, your talent is waisted sir !
I'll gte to my Fadal search now. Ragards, Steve
Thanks for the kind words, my day job challenges me a lot, nothing wasted.
absolutely fantastic video
Thank you
That was awsome. Although I knew the concept of power you still had me glued.
Thanks!
You I can understand!!!! Thanks for your time..
Welcome, thanks for the feedback
Fascinating! I love electricity, and this only helped spark my interest even more. Great explanation!
Thank you, I will be doing more of these, the touch probe videos are taking longer then I thought.
I enjoy the details
Thanks
Once again great video
Thank you CJ
There were some systems built early on that ran on 2 phase power in the Niagara Falls area. I've seen photos of Monarch lathes with 2 phase motors. As you pointed out, 3 phase is in the Goldie Locks zone for all around use and rapidly supplanted other proposed transmission systems and power equipment.
Of course the bane of home shops is the unavailability 3 phase and the hoops you have to jump through to either modify industrial motors to hobble by on single phase or by some method generate 3 phase power. Both options obliterate any performance gain that 3 phase offers. The only saving grace is the limited amount of time that equipment is usually run in the home shop.
You are correct, there was such a thing called "2 phase" power. But it was totally different then the split phase power in your home that some people confuse as being 2 phase. Real 2 phase power used 4 wires in most cases and sometimes used 3 wires with one conductor being larger then the other 2. That was the main issue why 3 phase won out over 2 phase. You could transmit the same amount of power using 3/4 the amount of wire. The reason they tried 2 phase was mainly for motor starting. Each phase was 90 degrees apart which gave a sin/cos wave. The other reason was the calculations for loads and such; back then no one had figured out how to calculate for 3 phase unbalanced loads. So it was easier to do the math on just a 2 phase system. I don't know why it is so hard to get 3 phase power into a home shop. If its on the pole and your willing to pay for the installation costs what is the big deal?
My experience is that the installation cost is so high that even for a commercial operation job shop that's not in an industrial area, buying a rotary phase converter is often the most economical way out. The power company certainly doesn't make it easy.
It depends on your area, if you have 3 phase at the pole and it only needs one transformer to step it down then the cost is not that bad. If you don't have 3 phase at the pole, which a lot of residential and rural areas don't, then they can not justify the cost with only one customer. Power companies hate phase converters, causes imbalances on the 3 phase grid. 3 phase power really does not like to have imbalances.
Super Lucid and Incredible :)
Thanks for the nice video. It explains a lot in a concise way.
Your Welcome, thanks for the feedback
Very cool. Thank you.
Welcome
It's just a phase, you will grow out of it!
LOL, thanks John, but I started with electronics at age 6 and the stuff I work on just keeps getting bigger!
Just could not resist the play on words, may be on the north side of 75 but the 12 year wise-ass kid old keeps popping up.
thank you very much, i just needed a reminder, and you were very helpful
Welcome
Thank you Professor.
LOL, Welcome!
Thank You very much sir! Need to know more..
This video was really helpful , thank you sir
Thank you
Welcome
good job.
Thank you
Very good explanation and clear
Thank you
Nice video, you explained the concepts well
Thank you Paul
Great explanations.
Thanks
A Great video and and great man
Thank you very much
I learned a lot
Thanks
Thanks for this video!
welcome
great video man i really found it helpful
Thank you
Great video man!!
Thank you Stephen
drink every time he says POWER! lol ......aanndd im dead.
You really made 3 phase AC easy to understand. Can you get 3 phase AC in your home?
The power company typically will not install it in a residence. If you have a shop, and there is 3 phase on the pole, SOME places will give you a service to the shop. My power company gave me the run around to no end, so I gave up. My machine is still small enough it can run on single phase without to big of an issue.
Could you tell me please about DC circuit neutral and how electron pass from neutral.Please.
DC just has a positive and negative side. Electrons flow in a continuous stream going one way.
Lease tell me the reciprocate saw in your analogy was cordless.... cos the irony would be perfect.
Yep, it was a cordless ;)
@@AtManUnlimitedMachining The irony: the reciprocating saw runs on a DC motor, and the band saw runs on an AC motor. Of course, it is what the mechanical machine is doing that is the analogy for the two forms of power, rather than what the motor is doing.
Great vid thanks
Welcome
Hmmm Butter!!
Great vid :D
Thank you Stephen, but ah, Butter?
We standardized on AC because technology didn't exist to use DC 120 years ago. You are now seeing more and more DC used for transmission in parts of the world that don't have the infrastructure built out (also in some countries that are more open to change). Good example are the Three Gorges Dam in China, underwater transmission lines and some parts of Europe. Why are they using what is called high-voltage, direct current (HVDC), because the costs are now lower and you have lower electrical losses than AC, technology has changed. We will probably never move to it here because at some point in the distant future localized power generation like solar or wind will happen (just like we will move all to metric some day but probably not in my lifetime, but it will happen).
Yes, there are and have been some DC transmission systems. But I'm not sure DC will ever over take AC for the bulk of transmission. Reliability and overload capacity are two huge factors for large power distribution systems. You just can't get more reliable then a simple coil of wire. AC transformers also have huge short duration overload capability, not so with DC converters. DC is only being used in a few very specific applications. Underwater power transmission as you mentioned is one of them. This is due to the underwater cable having significant more capacitance then just bare wires hanging from a pole. The capacitance of the wire consumes a lot of reactive power as the current flow changes directions. Maybe some day DC will have its day, but I don't think it will be any time soon with today's silicon.
My sparkie asked me if I wanted 3 live and earth or 3 live and neutral ? Why are there options ?
Hello Drew, if we are talking about 3 phase power there are two connection types. The first is Delta, in this case the load is connected to the 3 phases in a triangle. There is no neutral, only 3 phases and a ground, 4 wires total. The second is called Wye, here the load is connected like, well, a Y. The load is connected to 3 phases on one side and then center connected to form a neutral. There are 5 wires total, 3 phases, 1 neutral, and a ground. Note that with a Wye connection and a balanced load there will be no current flowing through the neutral. Current will only flow through the neutral if there is an unbalanced load. Hope that helps
Tim
I had a machine with a rated 3 phase 208 VAC,. if i had a system of 3 phase 220 VAC still applicable can it affect my machine??
It all depends on the machine, need to check the specs and see how high of voltage it can handle.
Thank you best explanation on for on single and three-phase question, I'm going to do a little experiment and build a Pelton hydroelectric generator if I use a 3-phase motor will I be able to run tools from my shop on it?
If you can make enough power and keep the voltage and frequency stable you should be able to. I would do the math to figure out if you have enough water to generate the amount of power you need, taking into account for the systems inefficiencies.
Yeah I'm going to try an experiment like a recirculating type of system with a solar-powered pump. I don't even know if it's possible but I like to try things just something like this sound feasible to you?
I would make sure to be extra careful in doing some math first. You are going to have a lot of inefficiencies with a system like that. You are probably going to lose 50% of the solar system capacity in losses.
Thanks for your time
Your welcome
So is 3 phase more efficient
In most cases yes, it is more efficient.
Reciprocatin.=reci-PRO-cating saw. Not recipicating.
Tomato, "Tamato", I'm from New York ;)
How do I know which phase a b or c phase is stronger
In a 3 phase system all phases should be balanced. Having a phase imbalance can cause many issues for equipment and the power company. If your using a rotary phase converter the one phase that comes from your utility will be the "strongest". You may see voltage differences using a phase converter. The generated phases wont be as stiff as the utility, meaning you will see much higher voltage drop under heavy loads.
2 phases are also can be used! but 3 are better. at 2 you need also 3 and have less good condition! and there is one large mistake! if the rotor of an induktion motor are a magnet by itself you create a synchronus motor! thats is not a induktion motor any more even if the outer part the stator is the same in many cases!
Hello, I don't think you will ever see a true 2 phase system in practice today. I have never seen one in use my self anywhere. Many people confuse the standard home electrical service in the US as a "2 Phase" system when in fact it is a single phase split system. Yes, if the rotor of a motor is a permanent magnet it is a synchronous type motor. This video was more of a discussion about power and not really motors yet, many people have the basic concept of a magnet in a motor rather then a squirrel cage. I will be doing in depth videos on motor types.
it was just an old idea and some enginers like the idea ! but he also say you have some good points in saving switches and fuses but thats all. on the other side there are some bad points
If a building has 208V 3 phase 4 wire, would it be an issue to install a 240V outlet for a machine that is rated for 2500W and 12amp draw? I was told by an electrician that is somehow a big deal and came here to learn for myself... I cannot see how it is an issue since 208V is 3 phases of 120V. I would appreciate any help!
I would not consider it a "big deal", but it is not as simple as adding an outlet and breaker. You will need to buy a step up or boost transformer to take the 208 and step it up to 240V. You can do this for a single phase or 3 phase load. You don't need a huge transformer, make sure to do proper calculations for sizing.
Thank you so much!!!
Your Welcome, good luck with the machine!
At-Man Unlimited Machining If you dont mind, could you explain for me how it is not as simple as adding a 240v outlet? Why is it an issue to draw 240v if 208v is 3 phases of 120V? I didn't know anything about electrics except for the formula W=I*V learned in school. Just starting to review and the basics now.
240V is a voltage seen in residential homes, it is single phase. In your house you have 3 wires coming in, two "hot" and one "neutral" If you measure the voltage from "hot" to the other "hot" you get 240V. If you measure from "hot" to "neutral" you get 120V, or half of 240. If you look at each 120V "leg" on an oscilloscope you would see there 180 degrees out of phase. So when one is at peak, the other is at valley and you get 240V. Now lets talk about commercial power, it is not single phase, but is now 3 phase. The original poster has 3 phase 4 wire system (actually 5 if you add the ground). In this case you have 3 "hot" lines and one "neutral". If you measure between any of the "hot" lines and the "neutral" you will again get 120V. However, if you measure between any two of the "hot" lines you will only get 208 volts, not 240. The reason is because unlike the residential single phase power that is 180 degrees out of phase, the 3 phase system in commercial is 120 degrees out of phase. So when one "hot" line is at peak the other "hot" lines are not at there valley, which results is seeing a lower voltage. If you use a voltage with a device that is lower then its design voltage, it will need to draw more current to use the same amount of power, that is your W=I*V equation. More current means more restive losses in the device and more internal heating, not good for the device. In these cases, you use a step up transformer to step the 208V up to 240V so the device runs at the correct design voltage. Many devices, like welders and some machines will have different "taps" on them to operate at 240V or 208V so they can be used on single phase or 3 phase power systems.
Hope that helps, Tim
so why do we need dc lets make everything use ac only
DC is needed for electronics. Many of the silicone devices need DC power for various reasons. Variable speed drives also need AC at various frequencies and the more efficient way to do that is by using electronics to make a DC bus and then again converting back to AC at a controllable frequency.
DC stands for defore christ
AC stands for after christ.
AC/DC name of rock band
Pretty good one too
@@AtManUnlimitedMachining why only 50 or 60 Hz?
That is a complex answer, like many things it is a compromise. 50/60 Hz was not the standard at first. The Niagara power project first used 25 Hz. This worked well for transmission and for the motors of the time, but light bulbs would have a noticeable flicker to them. They also used 40 Hz and some tried 133 Hz. Aircraft use 400 Hz systems. It is a balance between transmission losses and equipment size mainly. 60 Hz has an acceptable amount of transmission losses, while allowing for the reduction in the size of transformers and motors. Lower frequencies would yield lower transmission losses but require more iron and copper for every transformer. The opposite for higher frequencies. Aircraft use high frequencies because they are not transmitting the power very far and really need to save weight, so they use 400 Hz.
@@AtManUnlimitedMachining i see now,power losses is main problem for higher frequencies,i think it is similar with DC problem about power losses due the transmision am i right?
The issue is more complex then that. If you look at what causes the losses for DC power in a wire, it is purely restive in nature. However, with AC, the losses are from the impedance of the wire, which takes into account the capacitance and inductance of the wire with its resistance and the frequency. The main reason AC is used is conversion. You only need two coils of wire and you can step up the voltage of an AC system very cheap and easy. The higher the voltage, the lower the current given the same amount of power. Lower the current, you get less losses from heating up the wire. Most power is transmitted today well over 100,000 volts with lines as high as 1,000,000 volts being built. There are DC power transmission lines today, but the technology did not become viable until about the 1960's to convert and handle that high of DC voltage.
😵😵🤢🤢
That bad? Tried to relate it to mechanical terms ;)