Building a Phase Converter - Part 1

[@profesonalantagonist]

The best phase converter video I’ve seen yet.

[@zombieprinting2670]

Exactly the series I needed! Open wire diagram and great explanation. Too many people complicate this and make it hard when it's not. Thanks very much. I have 3 phase in my shop now :)

[@victoryfirst2878]

I have to totally be honest with you Birdranch. This is the first video I have seen that totally goes over all the relevant points in down to earth language. I am wondering why others on KZbin have not figured out how to be so simple and to the point. Frankly this is just refreshing to see and hear your explanations. Great job fella. You should get an award for being number one. YOU ROCK FOR SURE. VF

[@1969Kakashi]

This is how KZbin should be done. Thanks for the efforts. They have been well received.

[@davehiggins5903]

Wow, best instructions on phase converters I ever saw. Thank you.

[@marcellemay7721]

Great video on sizing and methodology of inserting the capacitors. Everyone else just seems to gloss over this very important step. Well done!

[@sbirdranch]

Thanks. That is what motivated the making of this series. No details in others I found. ~P

[@charlesleiker8896]

@@sbirdranch Do you have a schematic available?

[@sbirdranch]

@@charlesleiker8896 there is a document link in the description.

[@MrWaalkman]

Or just skip them entirely. This is how I've built converters in the past with no problems. But I will admit that this is a much better way of doing things.

[@CrawfordAutomation]

For my college course I'm building a 120v stepdown to 15v 1ph AC then making a 15v rotary phase converter... You have no idea how much this video helps.

[@Engineer-Machinist]

Thank you! I bought a Phoenix phase converter and it came from the factory out of balance. I didn't realize this till recently. They said to add capacitors to fix it and this was a great resource!

[@sbirdranch]

I shake my head that they didn't balance it to start. I hope the price was very inexpensive. Also glad you got it squared away. ~P

[@MrWaalkman]

Re-watching this as I have one to build. Couldn't help but notice the old school Amprobe like the one that I have had since I was a cub. :)

[@diglesspaul]

Absolutely the best rotary phase converter series on youtube. Thanks for taking the time to enlighten us. I bought a used, homemade one, with no diagram, not connected to the pony motor, and i was pulling my hair out trying to figure it out. Thanks again!

[@cowboyyoga]

Wow! Did I ever! It is the first time in all the time spent figuring out how to do this - that I feel comfortable! Thank you! Subscribed! And will watch the rest of the series.

[@Plus8Precision]

First off great video series, the most common sense explanation of a rotary phase converter build and testing on youtube.

[@rupert5390]

Doug I have read & watched so much crap over about three years trying to build one - this is by far the very best tutorial - you are a genius - I have to deal with trying to step up to 415v with a reverse wired transformer but your set up is ace.

[@wm79198]

Wow! Breaking it down to the essential components was very helpfull. Thanks for taking the time to make this series.

[@randywright918]

Followed this Great Build making me a 10HP 3 phase for my shop! Works perfect for my Horizontal Milling machine and Grinder. Tuning Capacitors was lot of trial and error, Thank you from bottom of my heart I can troubleshoot and repair my own Unit! Randy

[@metalfabman5477]

What an excellent understandable tutorial you have put together for someone wanting to build their own converter! Wish I would have had this 20 yrs ago when I built mine and did all these very same steps as I figured out my start and run caps. You have made a seemingly complex subject very understandable for a first timer!! Kudos to you and all your efforts to help someone else you don't even know. Just Excellent!!😃

[@ROLANDOULIGAN]

This is better than learning at some schools. Salute for the effort sir!

[@gruobn7482]

So far this was the best phase converter video I have seen. Thanks.

[@krazyhartin]

This is a well explained video. I watched other videos about these rotary converters but I never got a full explanation on how they work and how to balance them. Thank you. 👍

[@sbirdranch]

Glad you liked it!

[@StormbringerMM]

Just commenting again - this is exceedingly well done. I prefer this version over adding in yet another motor to remove the back emf resisting the initial start. Literally less moving parts.

[@tonyd4046]

Thank you so much for your instructions. Now I can build my own with confidence. I was confused about amount of capacitors. Again, please keep us awake with anything news under your knowledge.

[@sbirdranch]

Glad I could help

[@johncornwall7903]

❤thanks much for that video i follow it and made a rotary converter to run two peices of tools did as you said just have to balance the legs still alittle lost on what are the requied voltages per leg but it is the BEST❤❤❤

[@ChrisUhlik]

Superbly explained and great reference document. One concern I have about rotary idler phase convertors like this is that the phases are +/- 90 degrees instead of +/- 120 degrees as in utility-supplied 3-phase systems. The L1 and L2 inputs are 180 degrees apart. 120 volts each (to ground and the power company's neutral) and 240 volts between the two phases. The synthesized idler leg driven by the pony motor and capacitors is right between L1 and L2, thus 90 degrees to each one. You will notice that if you measure your "ghost" voltage to ground, it will be about 240 volts rather than 120 volts like L1 and L2. This means ground isn't in the middle of your Wye any more. There are three phases and the voltages between them are all close to 240 volts, but they are not equal amplitude with respect to ground and they are not 120 degrees of offset between phases. Because of this, motor magnetics will not be optimally aligned and you should de-rate motors driven by this compared to the same motor driven from a true, 120 degree, 3 phase power supply.

[@thebandito368]

the 3 phase is not balance

[@unclejoeoakland]

This answers so much. Sir, you are a boone upon other tradesmen.

[@christiaanmeyer2215]

This guy is brilliant .followed everything step by step and it is working better than my 5.5kw vfd

[@robanderson6009]

Been looking into making one of these for a While and this is the first video that makes it make sense. Awesome video!

[@Nodularguy1]

Best video series on Homemade phase converter.

[@AM-dn4lk]

This is one of the best video illustration and tutorial on the subject. Thank you

[@sbirdranch]

Glad it was helpful!

[@michaelmeredith9470]

Best series of videos on this subject by far. Detailed yet clea well done

[@maxwright4387]

ah thank you very much for this. i just got a big three phase motor and wanted to build a rotary converter but couldn't find instructions on balancing. couple dudes show their converters with a bunch of capacitors but don't explain how they determined what to use and where. also that document is suuuper helpful. thumbs up

[@anthonyevers149]

Thank you. I just bought a 3 phase welder at a auction. At the time I had know idea it was 3 phase.

[@gs-me]

Good morning from Trinidad W.I. I recently acquired a delta 10" unisaw for my home workhop. The tablesaw is powered by a 5hp 3ph motor. I have since been pondering if to change the motor to a 1ph. Studying this video series. You make this so easy that I am gonna try this. Thanks for an excellent demo.

[@sbirdranch]

Good evening from Ohio, USA. You can make one of these. And down grading the Unisaw to 1ph would be sad. A 3hp table saw will not let you down, where small sometimes does. Good luck. ~P

[@gs-me]

sbirdranch Good morning again. No no I am not installing a 1hp motor....... but looking into building a phase converter as you have demonstrated. Also am told off and have seen a. 230v 3ph. 5hp run of a 220v 1ph supply. The motor was running off two capacitors with a bell stwich connected to one capacitor to get the motor up to speed. Some similarities to your push button stwich. Again there was one power loss,, I was told about 30%. Are you familiar with this approach and iff so. Please enlighten us novices. Thanks again.

[@jacain1234]

Awesome video. It's all about tuning the phase shift via capacitors.

[@alfredokoh8341]

Thanks a lot for the diagram and instructions !! really appreciate it !! please do not be tired of posting education videos like this !!

[@Okie-Tom]

As you said, this gives a much clearer idea on the capacitor use. One thing that has always confused me and you get all kinds of different answers on forums is the phase differences. You have an input power that that is 240 volt single phase where the two 120 lines are 180 degrees apart. Your pony motor and output power are 240 volt three phase but the phases are 120 degrees apart. So, is what your saying here is that using the capacitors are actually electrically moving the phases so they end up close to 120 degrees apart. I guess I am having trouble visualizing how you can start a 120 degree motor with 180 degree phasing power. Thanks, Tom

[@chiraldude]

Yeah!, me to. I would like to see the output on a scope and measure the actual phases. Must be some ugly harmonics flying around. Incoming is 180 then the cap absorbs some current and shifts it 90 degrees but that is still 30 degrees off. Maybe this is just a power factor thing where the phase difference gets kicked back onto the grid and is lost?

[@perspectivex]

I have the same confusion, what is the phase angle between the outputs of this circuit? It seems like the phase shift of a capacitor is 90° (www.allaboutcircuits.com/textbook/alternating-current/chpt-4/ac-capacitor-circuits), actually up to but not more than 90° (www.electronics-tutorials.ws/accircuits/ac-capacitance.html) so I'd think maybe the outputs are only some fraction of 90° apart, say 0 (take the input's phase as 0 for reference), then +90°. So motors might spin but there won't be as much power transferred from the lines to the motor and maybe (I'm not sure) they will also heat up more than they would with the norm of 120° difference between each phase in 3-phase.

[@killking402]

This is a fantastic display of how a rotary phase converter works! This was very helpful for understanding how a RPC functions, one component at a time. Very well broken down. Nice work!

[@mot6021]

Finally a video that explains things , is well made and complete. good job. Thanks

[@robertcharbeneau5040]

I watched your videos on this and it worked perfect! I built one using your instruction video. Thank you!!! Excellent video

[@sbirdranch]

Great. Glad it was of use. I have done a total of 3 now. All the same way. Enjoy the equipment you hook to it. ~P

[@buroughs]

Best explanation of a rotary phase converter build...well done!

[@tedm2416]

Super helpful! I've been using a 5hp phase converter for years. Problem is, it will not start a 7.5 hp motor in my 18" planer. Using this set-up to run my 7.5 means that "the board" becomes a "static" converter and my 7.5 will run at about 5hp output--which is plenty; it replaced a 3hp motor in a planer. Totally concise, and I have not even glanced at the paper you linked to.

[@gilbertodiaz-castro626]

Swap the 7.5HP with the 5HP and you will be all set then.

[@karlthompson1961]

Your video is the best I’ve seen on the subject matter. Great work, thank you. 👍🏻👍🏻👍🏻🇬🇧

[@sbirdranch]

Glad it was helpful!

[@sandystanley1237]

Probably one of the best, easiest video to understand. Thank you.

[@al9094]

Its OK to have a sense of hummer. Some video makers think they have to burn up tools just for the show. That's OK if you are just entertaining . I see you're video as educational. That's why I clicked to watch it and I did learn from it. Ty

[@robertcharbeneau5040]

In your phase convertor build I was curious what HP motor you used. Your video was excellent! I have a 20 hp motor 3 phase that I'm going to use. Ty

[@sbirdranch]

The rule of thumb is to use a motor at least one size larger than the largest motor you are going to drive. In my case that was a 5 up lathe so I used a 7.5hp motor for the converter. I have built two more since this video and they all perform well. ~P

[@billrick4729]

Very good explanation. One thing you could do for your starter capacitor is to hang a centrifugal switch on the motor; that output shaft isn't doing anything else but spin anyways. That would be closed when the motor is off and open up as soon as it comes up to speed. No worries about a relay that might burn out.

[@jafinch78]

Excellent hands on demonstration! Thanks for sharing!

[@karinka88]

Awesome 🤩 video, thanks, I needed to know the capacitor values and you showed me!

[@L_A_N_G_D_O_N]

Your video helped me 4 years ago when I built my first RPC. Been utilizing it again to rebuild a new and improved version of it now that I moved. I was having trouble somewhere so I pulled everything out of the cabinet and screwed it all down to a piece of plywood so I could see everything and what do you know, worked perfectly. Any time I need to learn something or have questions about something, KZbin is one of my first resources. After 10 plus years of utilizing YT I think your video here is probably the best video I’ve ever watched. As far as making something that seems so daunting, become easily achievable. (And I put some thought into that statement before posting it) Anyways, Thank you for the resource! I may account for 200 or so of the views. 👍

[@jeepersmurphy2570]

Thank you so much. Excellent video series. Best on KZbin. Actual guide

[@glennbevan8743]

You didn’t’ t talk about this but I would to know what voltage you get between A and Common B and common and G and common . I really like how you did your video made it easy to understand that make up on the board the way you did

[@tankerbill1431]

I would like to thank you very much for a great and easy to follow video. By following the videos I was able to build a 10 hp rotary convertor and it works great. If its ok and somebody is interested, I will list the cap values for the 10 hp.

[@sbirdranch]

List the values you used. They may very a little between idler motors but its a good start.

[@JulianMakes]

This is so perfectly explained, I think I’ll be making one for my lathe, thank you!!!

[@Savagetechie]

they are also really inefficient. better to buy a VFD.

[@gilbertodiaz-castro626]

@@Savagetechie That may be so, but when you have several machines to run the costs for the VFD's become prohibitive for a small/hobby shop.

[@Savagetechie]

@@gilbertodiaz-castro626 true the get costly on multiple machines and some motors won't like them. There is a type of rotary convertor that has a true neutral which is also reasonably efficient. Most rotary designs have pretty nasty neutrals.

[@68greengoat]

Awesome video, very good job of explaining the theory behind the concept

[@oliverdaly9030]

Hi It's Oliver again I really appreciate your quick response and explanation your explanation of the project is fantastic your make it look so simple compared to all the other videos Kind Regards and Thanks a lot Oliver

[@brainfarth]

Does it matter if you use more capacitance that is needed? I slapped 240 uf(all I had laying around) on my first legs and it balanced within 1v.

[@johnbolongo9978]

Great job......nicely put together and thank you.

[@occif2023]

"Admittingly missing some safety options" , I giggled at that. Almost everything I own is missing safety options . Borrowed time is my motto i guess. Nice video !

[@grom7826]

OSHA doesn't have authority in your castle !

[@jessebimbo6361]

Great great video love it question how do you size your supply power coming from your breaker panel for your rotary phase converter I plan on building one like yours but 20 horse so breaker size is my question thanks

[@Ldavidable]

How do I calculate what capacitors I can use for a 30 HP phone motor? I need to power a compressor with a 10 HP motor and a heater ventilation system. Great video. Thanks for sharing.

[@brainfarth]

I tried to turn over a 10 hp 3 phase motor with single and a pull-start. It would hum, not attempting to speed up, until blowing the 10 amp breaker. What do you think is causing this?

[@kenzayler8789]

Thank you for taking your time to explain this process..... One thing I would have liked to have seen in the video.... Would have been, how you came up with the start capacitor size or formula..... but Awesome job...... I have sent several friends to watch this video......

[@sbirdranch]

Great suggestion! To be honest I did some googling around and took a guess. Then I listened to how it sounded and proceeded. Dang little science in it, I'm sorry to say. ~P

[@rossthesparky4848]

Is there a table for phase converters showing minimum size circuit breaker protection protection per horsepower. I looking to connect a 100 hp 240v phase converter???

[@sbirdranch]

Not that I'm aware of. That is a big converter.

[@itanongmokayengineer]

wohhh... this video is the best thanks this is the step by step on how to do it this is how should teacher teach in the school

[@jhuzcelclear1887]

Thanks for the video ...very helpful and informative concepts...salute to the content creator....

[@johnsushchyk7933]

Thank you very much Great information It really helps clear the view of how to accomplish a build God bless you n your work

[@sbirdranch]

You are very welcome

[@gs-me]

Thank you for this video. I am building one now using a 7.5hp pony to power a 5hp unisaw. Are there any updates to this build process that you know or have revised e.g. additional switch gear. Using one capacitor on legs 1. N 2. Instead of 3 capacitors each?.....etc. Thanks for your video and the enormous help in simplyfliling this build.

[@sbirdranch]

Glad this set of videos helps so many people. I am building a 3rd one (another friend) and am going through the exact same process as I did here. Remember that the 'tuning' determines the capacitors needed and that is to some degree, unique for every pony motor. ~P

[@stuarth43]

@@sbirdranch I have spent 3 days, can not get voltage on ghost leg, just 30, l1 and l2 have same 235, 5hp used 100 fd caps, dunno what I have done wrong, could i send you a drawing simple layout CAD, POF, and whatever you can read, thanks Stu

[@charlybrown1605]

It is the best video that I have seen on the internet, thanks for your time. I'm from Guatemala, Centroamerica and is difficult to find information about this system in spanish. You video is very good. Thanks.

[@sbirdranch]

Your welcome. Glad it helped you. ~P

[@MphoSekese]

Could you run a 3 phase welder using this rotary phase changer maybe?

[@nikolaishriver7922]

Using a Baldor 5hp and have it setup this exact same way. Trying to go through the process of tuning it with capacitors. I crank it up and this is what I get: L1 + L2 = 245 L1+ Ghost = 205v L2 + Ghost 205v L1+Ghost+90mf = 213v L1+ Ghost + 90mf + 94mf = 216v L1+ Ghost + (BigA$$) 125mf = 290v, and the motor is flying way faster than it should. I’m just trying to get it close with a box of random large run capacitors I have before investing in anything, and I can’t get the voltage to climb on L1+Ghost with any combination of 90mf, 94mf, 70mf, and a 50mf. I haven’t had success with L2+ Ghost either. Do the capacitors have to be in parallel? Sequence? Does it make a difference? Do I have a bunch of bummed capacitors? Why is the 125 WAY too much on a single line?

[@jimspencer3072]

The way you laid it out was great, I can actually understand it all. The thing is I need an output of 415 Volts, how would I achieve that?

[@joeestes7096]

Awsome! Iam starting to get the picture! I only need to power a 2hp 3 phase motor on my clausing lathe. What's the difference between useing a poney motor and the large phase converter?

[@jessebimbo6361]

Since I’m using 220 volt Running a 20 hp motor my main panel breaker should be what size? Thank you

[@hakimbouamrane7563]

Great Job! Thank you for all explanations....

[@markcolquehoun2218]

I love how you break it down I wish I had your contact to help me with a small project

[@windeltubongbanua7456]

Thank you sir. Well explained. I have a problem sir on my phase converter. Can help me please. My 3phase pony induction motor is 11kw 6poles 200volts. My problem is when we energized the starting capacitor is always blown up.my starting capacitor is 100/125 VAC 1500/1800 MICRO FARAD. Thank you sir😊

[@8MADJACK]

Great video, very understandable, thanks for making it

[@JK-zl7vv]

You know you can get a current draw switch from the common, start, run of an old refrigerator compressor which will take the place of you having to push a start button, it will then be all automatic when you turn your power switch on. Great video :)

[@robertgift]

Well done! Thank you, SBR.

[@rcarpenter9508]

Very nice video but one thing I noticed is that you already have 200 plus volts on all 3 legs.I have a rpc 15 hp with out hooking the rpc up to anything I am getting 110 110 230.How do I bring the 110 legs up to where they all are close like you did.The issue is my time master lathe has a 7.5 hp motor wired Y 220.The lathe does great but at 1050 and 1400 rpm the lathe will not top out could you please help me with this thanks and awesome video.

[@nwobivalentine8865]

Can you put a list of the exact items u used it would really help me a lot please

[@maxsmith2320]

very nice tutorial, can you use any 3 phase motor as a ghost motor., how much Ams can you generate .

[@bene8019]

you never checked for phase clocking. you can have the same voltage to ground on all 3 but wildly dif, between the 3. how do you fix that?

[@MrLonstar]

In my opinion your videos on how to follow the Fitch Williams design are hands down the best available on the net....kudos for doing an excellent job. I see it's been about 6 months since you replied to comments/questions, but here it goes anyway..... My question is how you arrived at your goals for voltage when balancing it. I don't want to make this a long reply, so I'll skip the blah blah and hope you understand. I multiplied my initial number by 1.03/1.08 to determine my goals, and to double check my understanding of what I was doing, I looked at your numbers and did the same math. I can't figure out how you came up with your goal voltage numbers for Cp and Cs, so I guess I don't understand HOW to do the math to achieve the goal for my setup. Can you explain the math on how you arrived at your goal voltages based on your initial voltages?

[@turbo2ltr]

How does one calculate the starting cap value? I have a 20HP motor. I can't seem to find any guidance other than the general rule of 7uF per HP

[@gangleweed]

Hmmmm.....and just how would you adjust the capacitors manually to keep the phase voltages balanced.....they doo have to be balanced or you end up with overheating problems as the load fluctuates. The setup will start and run a 3 phase motor but you do not have any control over the loading that affects the phase voltages. In commercial RPC's they have an electronic sensing circuit that adjusts the capacitors as the loading fluctuates.

[@haroutzeitounian4187]

great explanation great thank you

[@chuckmatson7255]

Fantastic video. after you added the first run cap (about 12:23) you stated "now we an tell which letters were which" at the 3 phase power output, but didn't tell us which were which! please explain which are which and how you know. thanks

[@kenzayler8789]

He's explaining the legs L1, L2, L3, he wrote them on the board...

[@willardcain4598]

Can you tell me what size start capacitor I need to begin a converter build with a 20 hp motor and the information you used in your video where can I get it thank you

[@MaturePatriot]

Very Educational. This has clarified a lot of my questions. I need one to run my 3hp 3ph lathe.

[@BLDEVINE1]

You can also use a vfd with single phase 230volt input. Then you have unlimited speed control also.

[@MaturePatriot]

+byron devine - I am looking at another 3ph piece of equipment. The RPC will power both. From what I have seen VFDs cause a loss of torque on low end speeds.

[@jaspermcconnell6417]

Make sure to put all the start capacitors in when you do that portion of the build. I saw working up with the run caps and thought I was supposed to do the same for starts. The reduced amount caused a catastrophic failure of the caps.

[@MrLonstar]

Good to know, this explains why I burnt up my start caps! I used a 3ph, 3hp motor when building and testing, I didn't want to take the chance of doing damage to my intended motor, which is 10hp. When I got the 3hp to work fine, I connected the 10hp motor. I added a small uf start cap to boost the power a bit when I switched to the 10hp motor (it was all I had on hand), but knew the total MFD of the start caps I connected wasn't quite enough. I thought it would be ok until I bought a bigger cap. They started the motor a few times while doing the balancing with the run caps, but then they stopped working. Now I understand why. Thanks.

[@jamesmcalarney2991]

Thanks and hello from Las Vegas millwrights

[@trustno1482]

Gr888 series 👍 one question thou, can this method applied to a 2 phase input power l1 and l2 instead of a single phase 220 v??

[@josephmwangi2760]

Thanks for taking the time. Awesome video

[@consaka1]

I love this guy already. Guns are welcome but don't touch my tools. Reminds me of my old boss that ran a semi truck repair shop. Step one of being an apprentice was to get my own damn tools. lol

[@alchemy1]

I bought a three-phase to single-phase converter years ago and I used it for a year or so. Now what I want to do is to use to convert a single-phase to three-phase. Is it possible to use that very heavy box and just wire it in reverse, using single-phase as input or how does that work? From what I saw in my wiring today, back when I had used only two legs of the three legs of three-phase to get what I needed. Two outlets of 120V, AC. The heavy box is a 5k converter. I think I paid like $500 for it back when. I would say this thing weighs a good 150 lbs.

[@jeffbondurant1013]

Love your in depth explanation of this convertor build. my question is what size start capacitor do i need to start a 20HP motor? I see the biggest most places supply is 1000-1200 MFD. I think i would need more than that if 70mfd per HP. Thanks!

[@mekmice3554]

This video's very educational and will explain ,very thought out and well planned. But What is the wiring configuration on Terminals inside the Enclosure head of the motor?. I'm guessing you have about 9 leads Inside the enclosure head Of the motor.

[@OHBINEY]

I can't find the starting capacitors in Ghana 216-259 uF x 330 VAC. But I saw this in Ghana cd60 500mcf AC. And also what I saw in china are not 330vac but rather 480vac . Can any be used

[@martinniemi3778]

as long as the voltages are higher on the capacitors you're good

[@American_Made]

Is the ghost leg always the center leg because of phase shift in the power company supplied legs is always L1, L3 in a standard 3 phase sinusoidal wave form? Hope that makes sense. It almost doesn't to me when I read it back. lol. Tryin to figure out if the 2 legs provided by the power company are they always the L!, L3 sin waves?

[@edmanthey4770]

Does it matter weather the pony motor is an internally connected Wye instead of a Delta.