Digital phase shifter ?

[Billy Stray]

Does anybody have experience with a "myung youn"
Digital phase shifter, it keeps popping up in my searches. Seams to good to be true.

[Kevin Jenness]

If it seems too good to be true it probably is. I did a quick search without finding any description of how they work or cost. I was intrigued by the promise "Semi-permanent for life".

[Dan Friedrichs]

Seems like it's just a static phase converter. It passes the 2 hot legs through, and generates a 3rd that is phase-shifted enough to get the motor started.

[Bill Dufour]

I am going to guess it is a Hung Yang VFD. Hung Yang is the generic china vfd company sold by many. 3 horsepower around $130 US.
Just like Rong Fu is the generic chain made mill/dill company
Bill D

[Bill Dufour]

If it is really a phase shifter make sure it is not for Rf frequencies, like radar.
Bill D

[Billy Stray]

It's sold on Amazon, in all different sizes
A lot of how too videos on YouTube, by manufacturer from the Philippines.
It just looks so easy is all

[Kevin Jenness]

Looking at Amazon listings it appears that it puts out full-time 3 phase like a vfd or rotary converter but lacks the programming options (reversing, speed control, accel/decel times, etc.) of a vfd. I would want to know if that were the case before buying one. The poor translation of the description and answers to questions suggests vendor support may be weak. The prices are not all that compared to true vfds.

[Carl Beckett]

Looking at Amazon listings it appears that it puts out full-time 3 phase like a vfd or rotary converter but lacks the programming options (reversing, speed control, accel/decel times, etc.) of a vfd. I would want to know if that were the case before buying one. The poor translation of the description and answers to questions suggests vendor support may be weak. The prices are not all that compared to true vfds.

This is my interpretation. A VFD - but simply fixed output. This is attractive because it simplifies hookup and no programming required - when none is needed.

Price point seems no different than a programmable VFD. But if fewer components (and possibly smaller), and simplification, it might be viable option for running a single motor at a fixed speed (which is all that is needed in many cases)

[Bill Dufour]

Does it provide slow start and dynamic braking. How about reverse. Can it use. a brake resister?
Bill D

[Dan Friedrichs]

Guys, it's clearly just a static phase converter. The seller has them listed on Amazon and in reply to numerous questions about using them on 3-phase heating devices, they say "It will work but will only be 70% efficient. Will heat slower". That's what you'd expect if you hooked up 2 of the 3 legs. Other reviews note that the 2 legs just pass through.

It also appears to be a plastic box without a fan, and smaller than an equivalently-sized VFD. No way they are actually generating true 3 phase without any cooling.

You could easily build or buy a static phase converter (including this one, if you want), but it will reduce the HP of the connected motor by 2/3.

[Billy Stray]

At first I thought it was 3phase for dummies but clearly it IS to good to be true

[Rick Fisher]

I thought it was static, which it could be. I didn't see the 70% power but that says static. I did see that it mentioned not using a 3 phase brake, that made me think it was a VFD.

I have a digital phase converter, its as simple as 2 wires in and three wires out. Mine has a place for a ground, I didn't see that in the DPS ads. Mine wasn't $300.00 .. which was why I took an interest.

[Kevin Jenness]

Guys, it's clearly just a static phase converter. The seller has them listed on Amazon and in reply to numerous questions about using them on 3-phase heating devices, they say "It will work but will only be 70% efficient. Will heat slower". That's what you'd expect if you hooked up 2 of the 3 legs. Other reviews note that the 2 legs just pass through.

It also appears to be a plastic box without a fan, and smaller than an equivalently-sized VFD. No way they are actually generating true 3 phase without any cooling.

You could easily build or buy a static phase converter (including this one, if you want), but it will reduce the HP of the connected motor by 2/3.

It is not clear to me exactly what these do. Here are a couple of q&as from Amazon



Would a start/stop switch go before the dps, or between the dps and motor? (https://www.amazon.com/ask/questions/Tx33EFXM8KNJ2BE/ref=ask_ql_ql_al_hza)


Answer:
Dear customer,


Thank you for your kind inquiry for our DPS,

Normally, in the case of power start/stop switch, you could install it before DPS.
And in the case of magnetic contactor, you could install it between the DPS and motor.

If you have other questions, feel free to contact you anytime.
Have a good day.

Best regards,

Mark Ko/Myung Youn Electronics Co.,Ltd. see less (https://www.amazon.com/ask/questions/asin/B07F243HLG/4/ref=ask_ql_psf_ql_hza?isAnswered=true#)







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Question:
Whats the difference between this and a static phase converter? Will the motor be working 2/3 its rated power? (https://www.amazon.com/ask/questions/Tx34OP8IXN2JJ4I/ref=ask_ql_ql_al_hza)


Answer:
I do not know what you mean by 'Static Phase converter'. So let me tell you more about our products. Our product, DPS, is a digital phase shifter. This unit converts 220V single phase to three phase with about 85% efficiency. The converted three-phase power dynamically changes to three AC terminals and maintains an average efficiency of 85%. What makes this product different from some other companies is that the output is all three terminals even after the motor is running. see les (https://www.amazon.com/ask/questions/asin/B07F243HLG/4/ref=ask_ql_psf_ql_hza?isAnswered=true#)

The 85% figure, if accurate, rules out a typical static converter, and putting a magnetic starter between the unit and motor does not agree with typical vfd usage. A horse of a different color?

[Dan Friedrichs]

This unit converts 220V single phase to three phase with about 85% efficiency. The converted three-phase power dynamically changes to three AC terminals and maintains an average efficiency of 85%. What makes this product different from some other companies is that the output is all three terminals even after the motor is running.


Some of the replies said 70%, but even the 85% figure seems to imply it's not true 3-phase.

They can't possibly mean the device is 85% efficient at converting input power to output power, as for a 5HP unit, that would imply 600W being turned into heat at the box. Again, no fan and a plastic enclosure - no way that thing is dissipating 600W of heat.

So what they must be saying is that the load runs at 85% of its rated power, implying that it's doing something similar to a static phase converter where it passes through the 2 supply legs and generates a 3rd.

You may be right that it's not a "typical" static converter (which uses a capacitor to induce a phase shift) - maybe they use some power electronics.

[Bill Dufour]

I think there is something lost in translation but 85% plus 85% efficiency means 59% efficiency. You will need roughly 278% more single phase amps in then three phase amps out.
Single to three phase is 1.75 X amps if it was 100% efficient.
Bill D

[Billy Stray]

I thought it was static, which it could be. I didn't see the 70% power but that says static. I did see that it mentioned not using a 3 phase brake, that made me think it was a VFD.

I have a digital phase converter, its as simple as 2 wires in and three wires out. Mine has a place for a ground, I didn't see that in the DPS ads. Mine wasn't $300.00 .. which was why I took an interest.

So you actually have one ?
How is it working for you ?

[Rick Fisher]

So you actually have one ?
How is it working for you ?

I have a digital phase converter. Its a Phase Perfect 20hp which I bought new in about 2008. Its been fantastic and trouble free. It feeds a 3 Phase Panel which distributes power to half a dozen machines. Its a good system. Phase Perfect is likely still the best system for 3 phase conversion. Its quiet, efficient, doesn't mind electric brakes, the power output is extremely balanced compared to say a Rotary which is good for CNC controls. Its a system you turn on and leave on while your in the shop. Turn it off when you leave.