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    Default Help with building a Transformer Phase Converter.

    I have a Scuba refill station with a 15 hp 3 phase 208 volt 42 amp motor. I recently purchased and read a book by Unique3Phase on the operation and construction of a transformer based converter.

    I'm no electrician but would like to try and construct on of these.

    Has anyone here built one and willing to answer some questions I have? I would also love to see some pictures of your transformer converters so I could see a visual of how it all comes together.

    Thank you so much for any help. It's very much appreciated.

    Jarrett Henderson

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    Quote Originally Posted by JarrettHenderson View Post
    I have a Scuba refill station with a 15 hp 3 phase 208 volt 42 amp motor. I recently purchased and read a book by Unique3Phase on the operation and construction of a transformer based converter.

    I'm no electrician but would like to try and construct on of these.

    Has anyone here built one and willing to answer some questions I have? I would also love to see some pictures of your transformer converters so I could see a visual of how it all comes together.

    Thank you so much for any help. It's very much appreciated.

    Jarrett Henderson
    I'm no galactic traveler, either. Not YET, anyway. But would "like to construct" a faster-than-light spaceship drive as well. After all, there's TONS of Sci-Fi books and movies where those are taken for granted, yah?

    Ever wonder why NEITHER item is not already settin' on the shelf as ready-to-buy in "the REAL world"?

    Some kool-aid ain't yet ready for prime-time, perhaps?

    By comparison? Rotary Phase converters JFW. Neither of weird physics nor leaps of faith required.

    Guess why they work? The pilot or "idler" motor is functioning as... ta da . a transformer.

    Rotary and dynamically coupled one, actually. Can't match the movement's contribution for effective coupling with static goods even at a high multiple of the cost and mass, plus need of greater tolerance for inherently load-unstable "tuning".

    Go rotary or go solid-state - load-flexible Phase-Perfect or load-dedicated Vee Effing Dee.




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    Quote Originally Posted by thermite View Post
    I'm no galactic traveler, either. Not YET, anyway. But would "like to construct" a faster-than-light spaceship drive as well. After all, there's TONS of Sci-Fi books and movies where those are taken for granted, yah?

    Ever wonder why NEITHER item is not already settin' on the shelf as ready-to-buy in "the REAL world"?

    Some kool-aid ain't yet ready for prime-time, perhaps?

    By comparison? Rotary Phase converters JFW. Neither of weird physics nor leaps of faith required.

    Guess why they work? The pilot or "idler" motor is functioning as... ta da . a transformer.

    Rotary and dynamically coupled one, actually. Can't match the movement's contribution for effective coupling with static goods even at a high multiple of the cost and mass, plus need of greater tolerance for inherently load-unstable "tuning".

    Go rotary or go solid-state - load-flexible Phase-Perfect or load-dedicated Vee Effing Dee.





    Thank you for the post. From the research I have done, The transformer converter is the better option with the compressor i'm running. Rotary, Phase Perfect and VFD are all much, much more expensive. The converter built using the "Unique3Phase" method has been proven to deliver balanced power and give many years of longevity.

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    Not sure if you are a spammer or a legit poster.... likely a spammer, considering the insistence on a particular brand name, and post history.

    BUT......The transformer based type is perfectly fine for one type load.... a constant load. like an irrigation pump, that runs at the same power level all day.

    For a scuba pump, which I would assume has a variable load, probably not so good. And an RPC can be quite cheap, to contradict your comment.

    So it appears you may be on the wrong path starting out.

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    We've given out comments and advise. For the sake of the respondents here please build one of the transformer convertors and tell us how well it works.

    Tom

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    Quote Originally Posted by JarrettHenderson View Post
    Thank you for the post. From the research I have done, The transformer converter is the better option with the compressor i'm running. Rotary, Phase Perfect and VFD are all much, much more expensive. The converter built using the "Unique3Phase" method has been proven to deliver balanced power and give many years of longevity.
    No. Actually, it has not.

    More "research" might also inform a body just how much larger, heavier, and more expensive - priced Copper or even Aluminium wire of late? - a static transformer rig actually has to be for any variation at all in its load - "tuned circuit" as it is.

    And/or/also that horse manure is a fair decent fertilizer.. IF you are intent of growing a certain type of crop.

    That said, I have yet to see anyone touting "phase conversion" of grasses and cereal grains to manure using a particular breed of horse as the "transformer" off the back of proven greater efficiency and lower cost. Camelid or Bovine critters, mayhap, horses not so much. Digestive system optimized for rapid mobility, not fermenting a cud to break down celluloses, etc.

    So yah have a "first" on that score if nothing else, and we no longer class it as USEFUL as "manure".

    Folks here may have been born at morning, noon, or night. But it wasn't YESTERDAY morning, noon, or night.

    We simply label yer spew as horseshit and go do something that involves less OF it.

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    Quote Originally Posted by thermite View Post
    More "research" might also inform a body that horse manure is a fair decent fertilizer.. IF you are intent of growing a certain type of crop.

    That said, I have yet to see anyone touting "phase conversion" of grasses and cereal grains to manure using a particular breed of horse as the "transformer" off the back of proven greater efficiency and lower cost. Camelid or Bovine critters, mayhap, horses not so much. Digestive system optimized for rapid mobility, not fermenting a cud to break down celluloses, etc.

    So yah have a "first" on that score if nothing else, and we no longer class it as USEFUL as "manure".

    Folks here may have been born at morning, noon, or night. But it wasn't YESTERDAY morning, noon, or night.

    We simply label yer spew as horseshit and go do something that involves less OF it.
    Well, THAT escalated quickly...

    Dave H. (the other one)

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    I can promise you i'm not a spammer. I came to this forum cause I thought maybe some people would be running this type of converter. Obviously I am wrong.

    Want proof of one of these in action with a balanced load ? Well here you go.

    YouTube


    This guy doesn't sale them but consults on the construction of them.

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    Quote Originally Posted by Hopefuldave View Post
    Well, THAT escalated quickly...

    Dave H. (the other one)
    And why would it not? Serious bizness afoot, the whole dam' wurld has to "socially isolate" over virus carriers, new within the most recent half a year

    Where do aircraft carriers for damned-foolishness over hundred-plus year exploration and actual practice gain an exemption?

    Transformers didn't just predate power distribution. They enabled it.

    Q: Why would anything actually USEFUL have been missed for over a hundred years?

    A: It wasn't. Missed. Nor useful.


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    Default JST I need you!

    I would like someone like JST to explain how the circuit functions. Clearly the video did not show any components or circuit diagram. I noticed that when the motor was running unloaded that the phase currents were WAY out of balance. My guess that it is similar to a static phase convertor which really isn't a phase convertor but more to just get a motor started and then runs open delta.

    Tom

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    Quote Originally Posted by TDegenhart View Post
    I would like someone like JST to explain how the circuit functions. Clearly the video did not show any components or circuit diagram. I noticed that when the motor was running unloaded that the phase currents were WAY out of balance. My guess that it is similar to a static phase convertor which really isn't a phase convertor but more to just get a motor started and then runs open delta.

    Tom
    Close. VERY close.

    EITHER of static lumped capacitance OR static lumped inductance can be used "alone" to shift the phase of a waveform. L-C combinations, even better-yet.

    Capacitors are smaller, lighter, and cheaper than great masses of Iron and wire.
    They do not LAST as long as inductors if "enough" smaller and lighter to BE "cheaper", but they last "long enough".

    So much for "static" or "passive".

    Now add a dynamic "contributor".

    - The "rotary-transformer" of an RPC pilot/idler, or

    - The Solid-State switching of a Phase-Perfect, an inverter, or a VFD.

    One, several, or ALL of, output quality, suitability to variable loading, general performance out of a given spend, mass, and physical SPACE, and/or efficiency and/or economic value-for-money at full "life cycle costing" further improve.

    Which is why we USE them at 50 - 60 Hz. Or even 400 Hz.

    Rather than spend space and MONEY on great masses of Iron and wire.

    Broadcast radio and higher frequencies, yet? Dif'rent story.

    Lighter inductors. Smaller capacitors, Less Iron and wire. Soon NO Iron at all and wires so short as to be near-as-dammit "all gone".

    Winding a motor to run off AM radio - you should happen to be sitting right under the tower? It was found simpler to rectify the "free" power and use an ignorant DC motor!

    Not that you'd want to LIVE or operate a shop as close as that, BTW.
    See "diathermy". Or recipes for roast pork, humans reportedly tasting much the same.


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    Actually, the ones I know about (might not be THAT one), can produce, at one load point, a very nice balance.

    Two things...

    A capacitor can produce a phase shift of 90 deg.

    The shift in the Scott connection is 90 deg.

    So, starting with a standard center tapped 240V system, one can boost the voltage, apply it from the center tap to the "manufactured leg", and shift it by 90 deg. If that is all done right, then the result CAN be good 3 phase.

    I've done it successfully in both directions, from single to 3 phase, and from 3 phase to single phase.

    It is the devil to get it balanced if the load is not constant. The compressor load for a fairly constant airflow might be OK, but something really steady, like pumping water to a certain height at a constant flow rate is super good, you can adjust it, and just let t be.

    The phase /balance can be done by a combination of the selected boost voltage and the capacitance used.

    In any case, yes, it can work, you have various secondary effects to deal with, but it can be pretty efficient and effective.

    However, as soon as the load changes, the conditions are messed up, and depending on just how you have it set up, that may throw off balance more or less. There are ways around that*, and the one shown may be using one of those. We decided that for our need, it was not suitable.

    For a shop converter, it's not practical. For a constant "flow-type" load, it can be OK. The biggest benefit is that it uses non-moving parts, so it can be reliable. It's the sort of thing that can be left in a shack out in the fields without having to worry about it much.

    * The balance issue can be worked around, for instance by having a box full of capacitors (the video hinted at that), and switching them in or out to cover a range of loads. That takes a controller.

    If it got to that point, I'd set up a pony-start simple RPC and have 3 phase before the system diagram was done for the fancy cap-changing system.

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    Quote Originally Posted by JST View Post
    Actually, the ones I know about (might not be THAT one), can produce, at one load point, a very nice balance.

    Two things...

    A capacitor can produce a phase shift of 90 deg.

    The shift in the Scott connection is 90 deg.

    So, starting with a standard center tapped 240V system, one can boost the voltage, apply it from the center tap to the "manufactured leg", and shift it by 90 deg. If that is all done right, then the result CAN be good 3 phase.

    I've done it successfully in both directions, from single to 3 phase, and from 3 phase to single phase.

    It is the devil to get it balanced if the load is not constant. The compressor load for a fairly constant airflow might be OK, but something really steady, like pumping water to a certain height at a constant flow rate is super good, you can adjust it, and just let t be.

    The phase /balance can be done by a combination of the selected boost voltage and the capacitance used.

    In any case, yes, it can work, you have various secondary effects to deal with, but it can be pretty efficient and effective.

    However, as soon as the load changes, the conditions are messed up, and depending on just how you have it set up, that may throw off balance more or less. There are ways around that*, and the one shown may be using one of those. We decided that for our need, it was not suitable.

    For a shop converter, it's not practical. For a constant "flow-type" load, it can be OK. The biggest benefit is that it uses non-moving parts, so it can be reliable.

    * The balance issue can be worked around, for instance by having a box full of capacitors (the video hinted at that), and switching them in or out to cover a range of loads. That takes a controller.

    If it got to that point, I'd set up a pony-start simple RPC and have 3 phase before the system diagram was done for the fancy cap-changing system.
    J?

    You must have come in the side door?

    The OP was all on about transformers and NOT capacitors. Seemed to think he could build a free lunch off 'em, yet.

    Same physics, other side, to do the do with only inductors, but cumbersome, massive, and costly as all-get-out at typical line frequencies when yah don't HAVE to.

    Only ever shot the ONE horsefly with a .22 rifle because the suicidal fool had landed on the muzzle, then crawled into the barrel. Shockwave prolly got him. Not likely the hollowpoint had to earn its crust.

    An all-transformer phase-converter kinda falls into the same class?

    "Because it is possible". Not wise nor cost-effective?


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    Default Autotranformer Phase Converter

    Quote Originally Posted by JarrettHenderson View Post
    I have a Scuba refill station with a 15 hp 3 phase 208 volt 42 amp motor. I recently purchased and read a book by Unique3Phase on the operation and construction of a transformer based converter.

    I'm no electrician but would like to try and construct on of these.

    Has anyone here built one and willing to answer some questions I have? I would also love to see some pictures of your transformer converters so I could see a visual of how it all comes together.

    Thank you so much for any help. It's very much appreciated.

    Jarrett Henderson
    There are commercial makers of these type units. And also other ways of phase conversion.
    But most of the information contained here is older, and much of it is from users on other countries, some of it is no longer contained in the archives, since the site upgrades.

    The rotary phase converter, static electronic inverter (Phase Perfect) or the VFD method is the ones most discussed here. Looks like you awakened thermite the DC preacher and his babbling drawl, and got flamed for asking a reasonable question. Surprised that he didn't tell you you need to use a DC motor and controller. There is an ignore button for that, if it gets too mangy for you.

    The auto-transformer phase converter was first patented in 1947 Pat# 2,423,348 and has been modified and improved many times since then. You can look it up for yourself if interested.
    This is the link for it, but it appears to not be working properly at the moment.

    Ronk Add-A-Phase commercial units

    And a sampling of prior discussions here, for your preview. Listed in the order of oldest date first. This should get you started about learning about what you asked. Happy reading.

    Whats my best & cheapest route?


    Static Coverters

    If a Dynamic converter is a RPG then what is an Autoformer?

    using the transformer method to make 3 phase?

    The Super Fantastic Transformer Method - Amazing To Behold - Stupendous - 8th Wonder

    10HP 3 phase installed for under £120.

    SAF Ω

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    Jarrette,

    Read the posts suggested by SAF and come to your own conclusions. There are persons here who have neither the first hand knowledge of the method nor the theoretic s of the conversion.

    I started building auto-transformer converters in the early 80"s before VFDs were available. They do work, will provide a "soft start" and will work well under varying loads. If properly balanced will provide balanced FLA at full load and all legs at less than full load will vary but will not exceed FLA in any leg. They will start fully loaded motors. In many cases the balanced FLA will be less than nameplate. Proof ? read the links.

    With the Vfd's now available and Rotary's for multiple motors maybe not the best choice. Ronk's ADD-A-PHASE (the commercial version) has been in production since the 1950's.

    All the info for a decision is in the suggested links.

    I have a shop full of wood and metalworking equip including and air compressor using home made auto-transformer converters. All running with no problems.

    Joe

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    Here for your edjumification is some information. This type relies on the 90 degree phase shift mentioned above, but uses an autotransformer, which has been the traditional approach since the 1930s or so when I believe these were first made.





    You will notice that starting and running capacitors are included in this. That likely allows a better start.

    Yes, it is an "improved form" of the static converter, of the variety that uses a run capacitor. Somewhat related to the capacitor start motors that include a run capacitor.

    On a theoretical basis, as well as in practice, the type does not actually produce a good balance at every load. But by adjusting the voltage and capacitance a combination can be found that has a wider range than other combinations. The capacitor leg will tend to be more of a "current source" the higher the autotransformer voltage is made, which should improve balance over a range of loads.

    I am not sure why anyone would prefer this to a good RPC for supplying many loads, as you really need one bulky converter per load.

    THERMITE:

    In case you missed it, the "Unique" video mentioned, in the first minute or so, the "box of capacitors". Transformers alone cannot do the needed phase shift starting from single phase. (You CAN do a phase shift starting from 3 phase, in at least two different ways, depending on what you want as a result)

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    Quote Originally Posted by JarrettHenderson View Post
    I have a Scuba refill station with a 15 hp 3 phase 208 volt 42 amp motor.
    Get a simple Cedarburg starting or "static box" and put a smaller pulley on the motor to knock down the load approx. 25%

    Did this for years on a 10 h.p. air compressor.

    I got 7.5 hp of air, but it ran fine.

    As it is a single load (albeit changing as the pressure comes up) you could simply
    add some run cap's to help things a bit (get above 75%)

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    Myself when young did eagerly frequent
    Doctor and Saint and heard great argument
    About it and about: but evermore
    came out by the same door where in I went.

    Rubaiyat of Omar Khayyam, verse 27

    To make the conversion you have to shift phase somehow. Almost any amount of phase shift will work because that can be twisted into the one you want. The problem is that the two readily available phase shifting elements are inductance and capacitance and both change with load, so you have to compensate somehow. That is the name of the game and all the rest is noise.

    A transformer can be made to do that by changing taps or using a variable transformer such as a Variac or Powerstat.

    Making a variable capacitor that size is hard.

    465 miles of RG8/U coaxial cable would give a 90 degree phase shift that wouldn't vary with load. Resistive losses might be a problem, though.

    Remember the Tektronix oscilloscopes with the coil of coax that delayed the signal so it would trigger the trace before the signal got on the screen?

    Bill

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    [QUOTE=JarrettHenderson;3512245]I have a Scuba refill station with a 15 hp 3 phase 208 volt 42 amp motor.

    15 hp is a lot of inrush current. Be sure you have the appropriate sized single phase service to run this.

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    Quote Originally Posted by 9100 View Post

    Remember the Tektronix oscilloscopes with the coil of coax that delayed the signal so it would trigger the trace before the signal got on the screen?

    Bill
    You would only know about that if you removed the case from the scope chassis.


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