1 Phase to 3 Phase Rotary Converter - 230V to 415V

In this video I show you how I built a 1 phase to 3 phase rotary converter for my workshop. This converter takes a single phase 230v supply and generates a 415v three phase supply. This means that I can run industrial machines such as my lathe in my home workshop.

The converter works by starting a 230v-415v multi voltage 3 phase induction motor in delta using the live and neutal as 2 of the three phases. Start capacitors are connected from the live to the 3rd phase to get the system going.

Once up to speed the motor is switched to star and the neutral is taken to the star point. At this point the motor is generating 2 of the three phases with the other one being supplied by the single phase supply.

There are also a bank of capacitors connected in parallel across the output of the converter to balance the phases.

Parts used:

Steel angle 40x40x3mm
1mm aluminium steet
50x50x1mm aluminium angle
Casters 50mm
Direct to metal paint
Hardwood Ply 12mm + 18mm
Light Oak Stain

230-415 4KW Induction motor
16a 3 pin plug and socket
32a 5 pin plug and socket
3 core toughflex
5 core SY
Red+white+earth single core
16a type c mcb
4a type c mcb
4 x 4 pole 20a contractor
4 way n/o - n/c timer
motor overload with n/o - n/c aux contact
red,yel,green lamps
4 x voltage + current display unit
2 position switch
Start capacitors 3x100uF connected in parallel = 300 uF which is ~50uF / idler motor HP
Running capacitors: 40uF on phase 2 to 3 and 10uF on phase 1 to 3

Technical Videos that explain the system in more detail:

This is the video that I first watched that proved that the system was possible. Therefore credit goes to RODALCO2007 for the original idea.

Then there are 2 videos by Galvinizedsankey that go into a lot of detail. These really helped my in the design of this converter.

If you are looking for wiring diagrams I do not have any, however there is a chap on Ebay uk who sells plans. I did buy a set out of curiosity and his system works in the same way as this one.

Thank you and don't forget to SUBSCRIBE + LIKE + SHARE

Disclaimer: This video is meant for educational and entertainment purposes only. It is in no way meant to be a set of instructions and therefore no attempt should be made by any party to recreate what has been seen in this video. Any attempt to do so is done completely at your own risk. Electrical systems are dangerous and should only be worked on by a competent person. Failure to do so could result in serious injury or even death.

[Handmadeextreme]

I hope you enjoy my latest video. Let me know what you think.
Is there anything I could do better?

[coztac]

Ah YouTube you've supplied me with another brilliant channel where I can watch videos on things I don't understand nor will have to ever make, and yet I leave satisfied and happy especially with that cabling

[TDG]

As an electro technician, I appreciate your cable management job. I would recommend getting some thermal protection on the idler.

[samuellourenco]

Nice! At first, I was thinking it was a single phase motor and a three-phase generator sharing the same shaft, but that approach is much more efficient. Thumbs up!

[jakekot]

I like him using hand tools & not a ton of I/C machines most simply don't have. His layout & wiring is superb, like out of mid 20th C & I mean that in a good way. Will watch other videos. Thank you.

[DonQuichotteLiberia]

Aaaah, the Colin Furze of Electrical Engineering! Subscribed!

[tonyfrewin]

Brilliant build. I converted a couple of 3 phase motors about 25 years ago for a friend and it’s so satisfying when it works. Not as well done as your converter but a much more Heath Robinson job with a bit of trial and error with various capacitors and a home made current operated relay.

[kierranpurden]

I do love when people tidy up their wiring! Nice job

[KlusterYogo]

As an apprentice electrician - this was extremely satisfying to watch!

[felixar]

Could you replace that useless pulley with a fan for cooling, or with a flywheel to store some energy for the inrush when you start the lathe?

[slickmelb]

I have never seen so many armchair commandos on one subject, its just brilliant workmanship the mans workshop is like at best 6 mtr x 6 mtr so it built to suit his situation the ones saying why not just get a VFD dont know what a rotary can do compared to a static and electrical codes do vary country to country

[pulporock]

This is the only rotary phase converter I have seen where you show the voltage and current balance over the three phases.
Although you show for about a 1 second, if you could show the balancing with various loads that would be great.
We could also see the efficiency, assuming the displays are accurate.
Excellent job well done.

[eliotmansfield]

my dad simply replaced the three phase motors on his lathe and mill for single phase over 40 years ago - I inherited them and they are still going strong

[vegisaynom]

Really awesome project! Just subscribed, love these sorts of videos, being an electronic engineer myself i can appreciate how much effort goes into making something like that function properly. Really helps me learn more about useful higher voltage devices, looking forward to watching more in the future :)

[mihdogg]

Your Video did show quite clearly how one can build a rotary converter, that is the problem most have with single phase supply and 3 phase machines a next vid or info the with the wiring diagrams would be the icing on the cake nice one, , !

[mrfyxr]

I have watched several of your videos. You do some really nice TIG welding, and now I see you doing some professional looking electrical projects. I have liked and subscribed. Keep up the great videos.

[victoryfirst]

Very well done fella. I have to transport you to the other side of the pond for sure. Keep on making great videos for us all on YouTube to see. VF

[johnsumner]

It is always nice to watch someone work that takes their time and do it correctly. Your channel was in my suggested channel tab and I'm glad I took a gander. Get video and great execution, very clean work. Will be watching more of your videos.

[ethanpoole]

In fairness, three phase means a bit more than simply three lives. Three phase means three lives each of which has its phase angle, that is where along a sinewave each live’s voltage lies, separated by 120° from either of its two neighboring phases.

[TinkerInTheShop]

I'm both inspired and bewildered..! Great video. I have a 440v star only 2-speed 3ph motor (lathe) and I'm desperately trying to get it running using the original motor! I think this kind of thing can work.. but the 2-speed part adds an extra level of complexity that most people seem to be stumped by. Cheers from the South West UK