Three Ways To Run A Three Phase Motor On Single Phase, And the Pro's and Con's of Each Method #065

I show in detail three different methods for powering a three-phase motor with single phase power. I show all the parts, how they work together, and the pros and cons of each method. The goal is to also explain how it works, not just “put the wires here”.

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Notes:

1. Potential relays come in different ratings. So, you have to be sure you get one that matches the voltage of your motor. The one I show in the video says is is for "any potential" as long as the motor is rated for 120, or 240. Details in the link below.

2. Affiliate links to Amazon items shown in this video. Amazon gives me a small commission if you use the links below. Feel free to shop around though.

Packard Start Capacitor

Supco Potential Relay

Powerwell Run Capacitor 60 mf

Genteq Run Capacitor 35 mf

One example of a KB electronics VFD for 1 ph-3ph rated at 5.5 amps. Make sure you get one that's the right size for your application. Not necessarily this one.

Technical corrections

Nothing yet

Final Note:
PLEASE UNDERSTAND...I receive hundreds of messages on all platforms (email, Facebook, comments etc) asking for advice, and help with projects. At this volume, I simply can't do one on one advice. Thanks for your understanding on this.

[donaldcampbell]

For the person just learning. Needing a grasp to understand. This guy is it. He is far more advanced than the learning person needs. Yet talks to us like we are people. So humble. He is why YouTube was invented. To teach and help. Very smart man. Love the videos.

[perceive]

I just fabricated a 60hp 220acv 3ph 1780rpm roto phase for my machine shop. Fabricated a frame that bolts on top of the 60 hp motor then a 2hp 220acv 1780rpm is mounted to that frame. Pulleys on each motor are 6 inch diameter double Grove B Belt. I then start the 2HP pony motor to operating rpm, I use a spring loaded on and off switch for this operation when I release pressure on this toggle switch it returns to off position. When the 2 motors are at the 1780 rpm I then energize power to the 60 hp through a magnetic start switch. The 60 hp continues to run on 220 and producing the third Phantom leg= 3 phase power. Because there is no power going to the 2hp pup motor now it just spins along with the 60 hp motor. I don't balance the line voltages on the 60 hp but balance the voltages on the load motors at each machine with run capacitors with 15 ph being the highest. The beauty about getting the 60 hp up to speed before you apply power is there is very little voltage draw on the circuit. While the motor is running at no load the amp draw is about 27/28 then obviously goes up under load.I have made numerous units with this approach for other people and myself and they have operated for years and years with no problems, the only thing I do check depending how hard I work the load motors are the run capacitors because they will loose there efficiency. Anyways I thought I would share this with you. But thanks for your great and informative video.

[rachelsambrano]

Reading the voltage across run capacitor is Cool. Many Refrigerators used Current relays- the coil in series, Potential used parallel voltage, originally a more expensive method, where voltage is higher than line voltage, caused from back EMF. Seeing EMF with a meter can be a-kin to Christmas. Be careful with voltages higher than utility power.

[RollinShultz]

I bought a 220 / 480V Delta cabinet saw at auction. I had planned on using a VFD that costs around $260, but I choked on the 3hp and ended up getting a 5hp, so the VFDs were running aroung $800. I found a Delta VFD for $448 on ebay. It is a pretty advanced VFD with over 100 programmable settings. I use the ramp up/down features and there is a terminal board to which I have inserted a foot pedal control so that I can operate the power hands free.

In my opinion a good VFD is the best way to go no matter the price. I also had to rewire the motor from 480V to 220V. Or from wye to delta.

[ljbarcalla]

Thanks for sharing and your advice what applications can be applied with it.

[rmein]

All of you vids are very good at providing information. I am stuck trying to wire a motor @ 230 volts to a F off R drum switch. Connection diagram shows 4 with 5 or 8 on both switches. ????
It is a Smith Jones 2hp 1 ph. that was put on a Enco (RF30) Mill/drill.

[jvmiller]

Using a seperate motor as a phase converter is a very old school trick. Many of home machine shops have done this. But if you are powering a small single motor the VFD with a phase convertor is the way to go. Amazon has some china made versions that will run a 2hp off of 110v for 80-90 bucks.

[rogergregory]

just stick with inverters vfds as you call them I've been build control panels/electrical gear for a long time and never used any capacitor gear to run 3ph motors, you can buy low power very cheap inverters now and there very efficient

[blmkintaro]

I'm not sure if anyone mentioned it yet but the motor would need a very specific number of MFD to keep it going and not burn up the motor or capacitors

[WikkyPlays]

Ugh I have this same sorta motor at 10:00 mins but there's no way those RPMS are 3900 like it says on the motor and I'm using a VFD :(

[johngillon]

wish i had met someone like you when i was younger, I tried to understand this stuff over the years, and now at 70 yrs old I am starting to understand it when you explain it. You are so cool. thanks.

[The_Most_Chad_Of_Chads]

I’m a Journeyman Electrician and I’ve got to say watching your videos has taught me more than any class I ever took. Your videos are so informative yet so interesting. Awesome content.

[johnallison]

Jeremy, I've been watching your vids for some time, and you just keep getting better and better. Reckon you would have made a great science and tech teacher. Many thanks.

[jimmilne]

Jeremy, you are a perfect example of the American pride of excellence through independent investigation. Revealing one's own potential through learning and then giving it on to others by teaching is you by example. I love this channel. 72 years old and still learning here. And you - I would like to meet you someday - are the teacher I wish I had had when I was 12 years old! Thanks for your fine example and your channel content. Impressed I am!

The second option has issues because instead of the phases being equally spaced at 120 degrees, you have two spaced at 180 degrees and the other is at best 90 degrees, but he had worse. So the motor is fighting itself, which is why it gets so hot

[rvhill]

you Sir are the MR Rogers of electrical engineering, people can learn a lot from your vids!

[danrobinson]

I rarely comment on any how-to video, but I felt compelled to tell you what a great job you do with these. I have watched several, and the quality is consistently very high. You have the ability to convey complex ideas in a very straightforward way. Thank you.

[Wrongway]

Very cool. I've watched "HUNDREDS" of videos on this subject, and founds yours the most informative and easy to follow. I will definitely stay tuned. Thanks alot.

[jlibb]

This is a lot of information. Good to see you show the "not so good" options along with good options.

[scottcarlon]

⚒🛠🔧⚙️Super informative, glad to be part of your cobbling for fun network. I really think you’er such a wizard and gifted in your knowledge and presentation, and ability to explain in an entertaining and informative way. Thanks for the effort, hard work and personal time invested, its a true valued service you provide. 🍺🍺🍺🍺🍺