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I use that basic circuit on my milling machine. What is shown won't have much starting torque, and you'll need a start capacitor of up to 8 times the value of that run one momentarily connected in parallel with it. Also don't expect to get the rated output of the motor, because if you monitor the actual voltage across each phase, only the one between phase and neutral will be correct. One of the others will be higher, and the third lower, and the values will vary, depending on the load that is being driven. The start capacitor has the maximum number of starts/hour written on it. Exceeding that will produce magic smoke, and the necessity for a trip to the capacitor shop. Mine doesn't use that fancy relay, and uses old power factor correction capacitors for the run function.
I ran a three phase motor off single phase 220 volt AC (actually 250 volt) for nearly thirty years with a ROTORY contactor that was 1930's vintage, just like the 230 volt 3-phase Westinghouse motor on the Quincy 7 1/2 HP (? maybe 10 HP) two-stage three-cylinder air compressor with a 90 or 110 gallon ASTME tank I got used from a filling station, and sold a few years ago for twenty times what I paid for it to a fiberglas shop, and the buyer thought he STOLE it compared to a new compressor! He'd have to have bought an EPA "compliant" screw compressor new and HAD it installed. HE could install my old Quincy outside in a shed legally. I had never connected the water intercooler, but he did and it was fine. Mine wasn't a delta three-phase, it was a "star" three phase. I DID have to replace the "RUN" capacitor which bulged and leaked from age-a $120 item and while I was into it I replaced the three Vee-belts that were twice my age. It was an induction run repulsion motor that made the electric meter "JERK" violently when each pole of the motor passed, but it will probably run until 2134 when I think it was built in 1934! Yes, a modern Toshiba or Baldor could save some electricity, at the expense of motor-life. You don't get anything for free in life. I used to pump it up to 175 psi and shut it down and "run off the tank" all evening, and sometimes the next day! Oh, yeah, I forgot I had to re-build the second stage compressor early on-the poppet valves stuck and snapped, but I think it was about $50 to fix it from Quincy Parts, and no harder to fix than a lawnmower.
I was once at a shop that a guy had built and setup but only had 220 single phase power available because it was in a residential area. He was able to start and run 3 phase motors on 220 without a capacitor. It's a bit spooky but he would wrap a rope around the pulley and pull start the motor. Once it's running over a certain RPM it will run on 220 single/split phase so pulling the rope like starting a lawn mower would get the RPM up and then throwing the breaker once it was spinning would get it up to about full speed. Also once a single motor was running he was able to take the 3rd leg and use that to start other electrical motors that were 3 phase without using the pull start method. So he had multiple 3 phase motors setup on equipment with a line that linked the 3rd leg of each one together and starting up the shop from cold was a process of starting one motor with a rope and then just throwing the switch on anything else he wanted to run. An added bit of information that I can not confirm was that he would often leave them running for weeks on end even if he wasn't doing anything and his power bill was next to nothing because of the setup. From what I was told the power company came out to check things as his bills were often abnormally low and they thought he was stealing power before the meter somehow. They pulled the meter and it all shut off however. The theory was that because he had a residential meter it wasn't able to handle what he was doing with it and there was some sort of odd ripple feedback or something of that nature which prevented the meter from properly reading the power use because of the 3 phase setup where the 3rd leg was connected between multiple motors. Again I can not confirm this but I don't have any reason to think he was lying about it. I am also doubting that modern meters would have the same issues but the power company opted not to change it because they would have had a major cost to them with little gained return.
@@billrobert3226 Yeah, the old school mechanical ones can be messed up using a big magnet from an old speaker. I am sure the new ones have other things that will cause issue with them as well since they can either use shunts or CT clamps. I personally use CT clamps on my lines for my own personal meter.
I just use a cheap small single phase motor with a coupler to a larger 3 phase motor as a converter…. Avoids huge current surges and voltage drops. Most power tools can tolerate slight power factor errors
Yes, correct, you can drive a 3-phase motor using a Capacitor like that. . . . BUT the value of the Capacitor will only be correct for one size of motor and also for only one specific speed or Power output on that motor.. . . These days, it would be better to get a VFD drive unit, which can change single-phase to 3-phase.
Great video, thanks. You can start a 3 phase motor connected as you describe by momentarily connecting a heavy wattage resistance (I forget the resistance value) across where you have your capacitor. The motor will run, and is generates the third phase at its unconnected terminal. You now have a rotary converter, and you csn connect a normal 3 phase motor and its control circuit to your rotary converter.
That would not be a good idea.What it sounds like is you are trying to current limit a field with resistance but I can certainly assure you it will not run safely
@@firealarmapprentice4517 The resistance is only in circuit for a fraction of a second. Anyway, I have actually used this method of starting a three phase motor, it works, although my motor was under no load. I built a rotary converter.
So if you get a 3phase motor to "spin" on single phase its Great BUT... The single phase is 180 degrees out of phase, but the windings are 120 degrees out of phase. It would be like driving a car where the passenger wheel is turning left and the driver wheel is turning slight right.@@petertyrrell6690
It may not when running for prolonged periods. That is why I have mentioned that, this method is good to test a 3 phase motor or run for short periods only. Thank you.
From 3'54" rubbish - the overload relay does not detect zero current through T3 or anywhere else. The relay is designed to trip when all 3 lines are overloaded. When marginal overcurrent flows only through 2 lines, the thermal conditions for tripping are not satisfied and the relay will not trip. This is why, when using a 3 pole overload relay on a single phase motor, the load current must be taken through all 3 poles as illustrated.
Most overload relays will trip after a while if the load is extremely unbalanced but not overloaded. It could run for several days without any issues but suddenly it will trip.
Thermal overload relays are designed to protect motors based on the heat generated by the current. If there is an extreme imbalance in phase currents, even if the average current does not exceed the rated load, one or more phases may carry a much higher current than the others. This excessive current in one or more phases generates additional heat, causing the thermal relay to trip due to the increased temperature, even if the total load current is within acceptable limits.
The problem is that the phase shift between two phases of the 3phase is 120 ° but between the red and the black it is 180 °. So it may turn but it is far from optimal.
This is 3.8 kW motor. For 230 V AC supply, use 275 Microfarad 440 Volt capacitor. Please do this only for testing purposes. Continuous running is not recommended. Thank you.
I have done this before, on a tyre-changing machine, but wouldn't recommend it unless there was no other option. If you can afford it, a small VSD running off the single-phase supply is a much nicer option.
Gone seem to be the days of swapping two live connections in order to get the motor rotating correctly. Is the single phase operation covered in the IEEE Regs?
We recommed this method for testing purposes of a 3 phase motor and short period running of it. If you intend to run it continuously, best option is to go for a single phase to 3 phase converter.
What capasitor i use in 3 phase motor to single phase 220v? 3 phase motor specs.. Y DELTA 346-480/200-280V. 1.40/2.45 A COS♤ 0.80 0.55KW. 3400. 1/min. 60hz
@jacquesdebruyn6748 not always practical as single phase motors are larger a larger frame size than 3 phase for the same power output so if its going on a flange it will be to big to fit
@@wangaui correct..i recently did this on a 3 phase lathe we only have single phase source. If you put single phase motor it will surely not fit hahaha more expensive job.
puoi usare i sottotitoli tradotti. selezionare le impostazioni, contrassegnate come una ruota dentata sullo schermo. quindi seleziona i sottotitoli. quindi seleziona la traduzione automatica. nell'elenco delle lingue selezionare italiano. ottieni i sottotitoli in italiano.
This is apallingly misleading. I am an EE and have designed motor drives. What is the 3 ph voltage L-L? What is the single phase voltage L-N? How much power can you expect from the 3 ph motor? (not much!). How much starting torque, for a compressor, say (a common 3 ph application). Basically so simplistic as to be worthless and potentially dangerous. And why the speech synthesis? Struggled with microfarad!
25 hp means it is fairly a large motor with 18.5 kW power rating. For testing purposes, you can use 1300 microfarad, 400 V capacitor. Large motors like these, are not recomended for continuous running on load with this method.
Sorry but this concept is kind of nonsense, it wouldn't even turn over. Just use single phase motor, is more efficient. By the way you cannot start 3 phase motor without star delta switch unless you run it just with star connection with less power.
@bahn5ee you can also start 3 phase motors in delta configuration but they draw a lot of current so you do it only with small motors. Here in Germany you have to use a star-delta switch for motors above 6kW to avoid a voltage drop in the local energy grid. So your neighbors don't notice their lights getting dim for a split second while you are starting the motor...
What is the biggest size of motor can run single phase and you were saying 70 uf capacitor for 1kw so 3kw by 70 with be 210uf am I correct thanks please let me know
Yes it will work for a 3kW Motor, but not for continuous operation, it will get pretty warm... It will also have a relatively low torque when starting and less power output overall. So it is no replacement for 3phase power, it will work for small motors with no load at startup and manually variable load at operation, but not for most motors with a fixed load... So for example you can use it to power a bench grinder, but probably not for an air compressor or pressure washer ... If you don't want to lose power, the better option is to buy a VFD if you just have 1-2 3phase motors. If you have multiple motors it may be cheaper to buy a rotary converter... Of course, if you live in Europe the cheapest option is to just install a 3phase outlet (CEE), basically every domestic household already has 3phase power...
🔔Help Electro Academy grow! 🔔
Your support can make a big difference! 😍
If you appreciate the efforts behind these educational videos, please subscribe - it’s free and just a click away.!🙏🏽
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I am deeply grateful to our first sponsor! Your kind gestures motivate us to continue creating quality content. Let’s build this community together.!🏆
THANKS .!
- Sudarshan, Creator of Electro Academy
I need this vidoe
@@salamuddinissazada Thank you
This was the BEST presentation! With the windings shown it is easy to remember what one is actually doing. Thank you so much ❤❤
Thank you
This was the most straightforward and well explained and demonstrated example I have seen on YT! Great work, thanks!
Thank you
Superb and fantastic explanation and can understand very easily. Thank you very much
Thank you 👍
Sir your explanation way so simple to understand thank you ji 🙏
Thank you
Thank You
this is very useful knowledge
for our needs in the countryside
Thank you
I use that basic circuit on my milling machine. What is shown won't have much starting torque, and you'll need a start capacitor of up to 8 times the value of that run one momentarily connected in parallel with it. Also don't expect to get the rated output of the motor, because if you monitor the actual voltage across each phase, only the one between phase and neutral will be correct. One of the others will be higher, and the third lower, and the values will vary, depending on the load that is being driven. The start capacitor has the maximum number of starts/hour written on it. Exceeding that will produce magic smoke, and the necessity for a trip to the capacitor shop. Mine doesn't use that fancy relay, and uses old power factor correction capacitors for the run function.
Thank you
I subscribed your channel sir
Thank you
I ran a three phase motor off single phase 220 volt AC (actually 250 volt) for nearly thirty years with a ROTORY contactor that was 1930's vintage, just like the 230 volt 3-phase Westinghouse motor on the Quincy 7 1/2 HP (? maybe 10 HP) two-stage three-cylinder air compressor with a 90 or 110 gallon ASTME tank I got used from a filling station, and sold a few years ago for twenty times what I paid for it to a fiberglas shop, and the buyer thought he STOLE it compared to a new compressor! He'd have to have bought an EPA "compliant" screw compressor new and HAD it installed. HE could install my old Quincy outside in a shed legally. I had never connected the water intercooler, but he did and it was fine. Mine wasn't a delta three-phase, it was a "star" three phase. I DID have to replace the "RUN" capacitor which bulged and leaked from age-a $120 item and while I was into it I replaced the three Vee-belts that were twice my age. It was an induction run repulsion motor that made the electric meter "JERK" violently when each pole of the motor passed, but it will probably run until 2134 when I think it was built in 1934! Yes, a modern Toshiba or Baldor could save some electricity, at the expense of motor-life. You don't get anything for free in life. I used to pump it up to 175 psi and shut it down and "run off the tank" all evening, and sometimes the next day! Oh, yeah, I forgot I had to re-build the second stage compressor early on-the poppet valves stuck and snapped, but I think it was about $50 to fix it from Quincy Parts, and no harder to fix than a lawnmower.
Thanks for sharing your experience with us.
Good Job! I learned something today!
Thank you
I was once at a shop that a guy had built and setup but only had 220 single phase power available because it was in a residential area. He was able to start and run 3 phase motors on 220 without a capacitor. It's a bit spooky but he would wrap a rope around the pulley and pull start the motor. Once it's running over a certain RPM it will run on 220 single/split phase so pulling the rope like starting a lawn mower would get the RPM up and then throwing the breaker once it was spinning would get it up to about full speed.
Also once a single motor was running he was able to take the 3rd leg and use that to start other electrical motors that were 3 phase without using the pull start method. So he had multiple 3 phase motors setup on equipment with a line that linked the 3rd leg of each one together and starting up the shop from cold was a process of starting one motor with a rope and then just throwing the switch on anything else he wanted to run.
An added bit of information that I can not confirm was that he would often leave them running for weeks on end even if he wasn't doing anything and his power bill was next to nothing because of the setup. From what I was told the power company came out to check things as his bills were often abnormally low and they thought he was stealing power before the meter somehow. They pulled the meter and it all shut off however. The theory was that because he had a residential meter it wasn't able to handle what he was doing with it and there was some sort of odd ripple feedback or something of that nature which prevented the meter from properly reading the power use because of the 3 phase setup where the 3rd leg was connected between multiple motors. Again I can not confirm this but I don't have any reason to think he was lying about it. I am also doubting that modern meters would have the same issues but the power company opted not to change it because they would have had a major cost to them with little gained return.
I've heard many happy stories of bad meters giving the customer a discount!
@@billrobert3226 Yeah, the old school mechanical ones can be messed up using a big magnet from an old speaker. I am sure the new ones have other things that will cause issue with them as well since they can either use shunts or CT clamps. I personally use CT clamps on my lines for my own personal meter.
Without a capacitor, this is what you should do. Using a pulley...
fantastic, the presentation is really super.
Thank you
Sir thank you very much. I'm very interested
Thank you
Thanks,have heard of it but never seen one.
Nice bro... Continue good work.. ❤❤
Thank you
thank you and God bless you
Thank you
I just use a cheap small single phase motor with a coupler to a larger 3 phase motor as a converter…. Avoids huge current surges and voltage drops. Most power tools can tolerate slight power factor errors
Some 3 phase motors use star/delta starters to achieve soft start and to reduce starting current.
Yes, correct, you can drive a 3-phase motor using a Capacitor like that. . . . BUT the value of the Capacitor will only be correct for one size of motor and also for only one specific speed or Power output on that motor.. . . These days, it would be better to get a VFD drive unit, which can change single-phase to 3-phase.
Hi sir good evening very nice your circuit and explanation 👍
Thanks 🙏
Please upload single phase supply to three phase vrd circuit how to make
Thank you
Vfd is the way to go. You can make a small air compressor produce high volume of air. For air tools.
Thank you!
Thank you.
so lovely
Thank you
Yes, this will run as a splt phase motor, but only at a very reduced output.
Great video, thanks. You can start a 3 phase motor connected as you describe by momentarily connecting a heavy wattage resistance (I forget the resistance value) across where you have your capacitor. The motor will run, and is generates the third phase at its unconnected terminal. You now have a rotary converter, and you csn connect a normal 3 phase motor and its control circuit to your rotary converter.
Thank you
That would not be a good idea.What it sounds like is you are trying to current limit a field with resistance but I can certainly assure you it will not run safely
@@firealarmapprentice4517 The resistance is only in circuit for a fraction of a second. Anyway, I have actually used this method of starting a three phase motor, it works, although my motor was under no load. I built a rotary converter.
So if you get a 3phase motor to "spin" on single phase its Great BUT... The single phase is 180 degrees out of phase, but the windings are 120 degrees out of phase. It would be like driving a car where the passenger wheel is turning left and the driver wheel is turning slight right.@@petertyrrell6690
And also shared your channel
Thank you 👍
thank you for brief explanation. is the motor have the same energy running by three phase power supply and single phase power supply
It may not when running for prolonged periods.
That is why I have mentioned that, this method is good to test a 3 phase motor or run for short periods only.
Thank you.
Wow! I'd like to see that.
Thank you
also works with split phase 120 volts AC = 240 volts between the two phases instead of the neutral wire.
this is in my exam on my 5th year in Electrical engineering!😂
Thanks for the comment
Thankfully sir
Thank you
From 3'54" rubbish - the overload relay does not detect zero current through T3 or anywhere else. The relay is designed to trip when all 3 lines are overloaded. When marginal overcurrent flows only through 2 lines, the thermal conditions for tripping are not satisfied and the relay will not trip. This is why, when using a 3 pole overload relay on a single phase motor, the load current must be taken through all 3 poles as illustrated.
Most overload relays will trip after a while if the load is extremely unbalanced but not overloaded. It could run for several days without any issues but suddenly it will trip.
Some overload relays also include phase loss protection. That is why it is proper to wire it as shown in the video.
Thermal overload relays are designed to protect motors based on the heat generated by the current.
If there is an extreme imbalance in phase currents, even if the average current does not exceed the rated load, one or more phases may carry a much higher current than the others.
This excessive current in one or more phases generates additional heat, causing the thermal relay to trip due to the increased temperature, even if the total load current is within acceptable limits.
And watch the lights in the house diminish to nothing LMAO
The problem is that the phase shift between two phases of the 3phase is 120 ° but between the red and the black it is 180 °. So it may turn but it is far from optimal.
What I miss are the control of the voltages on the motor terminals.
These should be nearly equal across the three points with a running motor.
That's same as my old air compressor setup 😂
❤
Thank you
Excellent sir
5hp motor
full load current 9 Amps
Please tell me capacitor rating
This is 3.8 kW motor.
For 230 V AC supply, use 275 Microfarad 440 Volt capacitor.
Please do this only for testing purposes.
Continuous running is not recommended.
Thank you.
I bought a digital phase converter
I have done this before, on a tyre-changing machine, but wouldn't recommend it unless there was no other option.
If you can afford it, a small VSD running off the single-phase supply is a much nicer option.
You mean VFD?
@@Jason-wc3fh A Variable Speed Drive aka a Variable Frequency Drive. Same beast by a slightly different name.
Gone seem to be the days of swapping two live connections in order to get the motor rotating correctly. Is the single phase operation covered in the IEEE Regs?
Thanks for your comment
How does this affect the motor efficiency? Do you need to increase the fuse and overload amp ratings?
We recommed this method for testing purposes of a 3 phase motor and short period running of it.
If you intend to run it continuously, best option is to go for a single phase to 3 phase converter.
👍
Thank you
Only if the motor itself is running.
Would it be better to use 2 phase or 1 line and neutral?
Some do this differently.
Best thing is to get help from an Electrician.
What capasitor i use in 3 phase motor to single phase 220v?
3 phase motor specs..
Y DELTA 346-480/200-280V. 1.40/2.45 A
COS♤ 0.80 0.55KW. 3400. 1/min. 60hz
40 uF (MFD) 370-440VAC
It may turn, but try to use it.
Nowadays you get a VFD that has single phase input and three phase output.
Plus you have the advantage of a soft start.
👍✌️👌👌👌👌🤗
Thank you
Just buy a single phase to 3 phase VFD
Spot on
Pretty sure I'd be cheaper to just go buy a single phase motor then....
@jacquesdebruyn6748 not always practical as single phase motors are larger a larger frame size than 3 phase for the same power output so if its going on a flange it will be to big to fit
@@wangaui correct..i recently did this on a 3 phase lathe we only have single phase source. If you put single phase motor it will surely not fit hahaha more expensive job.
There's a good reason why you have single phase and three phase
what much is capacity ?
Is it starter capacitor or run capacitor?
I think it is run capacitor..
If for start capacitor, its only for single phase motor
Run capacitor
electric chair :-)
In this method, does it possible to continuous run a motor? If possible, what is the maximum motor power???
the engine continues to run with reduced power
This method is not to run for prolong periods.
Use this method for short period running and for testing purposes only.
@@ElectroAcademyEA Yes,,thank you, Sir...
Add the start, stop button
Traduzione in italiano?
puoi usare i sottotitoli tradotti. selezionare le impostazioni, contrassegnate come una ruota dentata sullo schermo. quindi seleziona i sottotitoli. quindi seleziona la traduzione automatica. nell'elenco delle lingue selezionare italiano. ottieni i sottotitoli in italiano.
I'm not even gonna watch this and tell you to use a phase converter to operate a 3ph motor with 1ph power.
Thanks for your comment
Can’t see. What you’re doing you’re blocking it
@@06Machine You can stop appearing of subtitles by clicking "CC" tab on the video screen.
This is apallingly misleading. I am an EE and have designed motor drives. What is the 3 ph voltage L-L? What is the single phase voltage L-N? How much power can you expect from the 3 ph motor? (not much!). How much starting torque, for a compressor, say (a common 3 ph application). Basically so simplistic as to be worthless and potentially dangerous. And why the speech synthesis? Struggled with microfarad!
Many are using this method for testing of 3 phase motors, when 3 phase power is not available.
Connecting single phase to a 3 phase motor. That motor will loose 30% of its efficiency.
This should be for test run and for short period running only.
All motors are three phase, the reason for capacitors.
For testing of 3 phase motors when 3 phase supply is not available.
25hp motor tell me the capacitor rating. Sir
25 hp means it is fairly a large motor with 18.5 kW power rating.
For testing purposes, you can use 1300 microfarad, 400 V capacitor.
Large motors like these, are not recomended for continuous running on load with this method.
This will not startup of 3-phase motor under load cheapest way of doing called a pony motor
Sorry but this concept is kind of nonsense, it wouldn't even turn over. Just use single phase motor, is more efficient. By the way you cannot start 3 phase motor without star delta switch unless you run it just with star connection with less power.
@bahn5ee you can also start 3 phase motors in delta configuration but they draw a lot of current so you do it only with small motors.
Here in Germany you have to use a star-delta switch for motors above 6kW to avoid a voltage drop in the local energy grid. So your neighbors don't notice their lights getting dim for a split second while you are starting the motor...
Still many are using this method for testing of 3 phase motors, when 3 phase power is not available.
Not for running for prolonged periods.
Could you have possibly made this any more confusing?
Thanks for your comment
Fake
Thanks for your comment
Can you help with diagram on how to connect 1 phase 240v motor with two capacitors and reverse?
Will do when time permits
What is the biggest size of motor can run single phase and you were saying 70 uf capacitor for 1kw so 3kw by 70 with be 210uf am I correct thanks please let me know
Yes it will work for a 3kW Motor, but not for continuous operation, it will get pretty warm...
It will also have a relatively low torque when starting and less power output overall.
So it is no replacement for 3phase power, it will work for small motors with no load at startup and manually variable load at operation, but not for most motors with a fixed load...
So for example you can use it to power a bench grinder, but probably not for an air compressor or pressure washer ...
If you don't want to lose power, the better option is to buy a VFD if you just have 1-2 3phase motors. If you have multiple motors it may be cheaper to buy a rotary converter...
Of course, if you live in Europe the cheapest option is to just install a 3phase outlet (CEE), basically every domestic household already has 3phase power...
Yes. You are correct.