Digital or Rotary Phase Converters?

C

Calandrod

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I just asked this in GJ, but I’m thinking some people here might have good insights specifically related to the hobby.

So I am going to buy a small 5hp phase converter to run my 1.5hp Bridgeport. I have done some research into American Rotary Phase Converters and they use Baldor motors which I like, have a great warranty, have great customer service, and overall it seems like a very quality product. I’ve spent a long time talking to them and they have been helpful in figuring out what I need. The model I’ve been looking at is the ADX-5.

My father in law does a lot of electrical for his business and he likes the digital phase converters, specifically recommending the 5hp Phase Perfect digital converter.

Does anyone recommend one either way? They are equally priced so longevity and quality are main concerns. Thanks!
 
I'd consider that rotary phase converters are simple for the average person to fix if something goes wrong, I'd think the digital variety would be the opposite situation. Likely the digital variety is quiet, the rotary ones are just plain noisy and somewhat distracting. I made my own rotary, using a 7.5 HP motor, a static phase converter to start it and a bunch of oil filled capacitors; it works well and was cheap to build.
 
They are expensive options for running a single machine, in particular a mill. Most common these days is to buy a $300 VFD such as a Hitachi WJ200, Fuji Mini, Teco L510 in a 2 or 3 Hp model and just wire the VFD directly to the motor and add a switch for direction and speed. They do require some install skills, but very simple. A RPC runs all the time when you are using the machine(s) an needs an idler sized at least around 2X the motor you want to run, and would need to be wired in unless you bought one of their plug in models. Probably looking at $700-1000. Phase Perfect world be way overkill unless you plan on additional 3 phase equipment, but they do have a new "low cost" series which is somewhat in the price range ($960-1270) of factory RPC, and I would choose it over spending RPC 1K for an RPC. Their idle current is around 75-100W, they are quiet and they can be used with any 3 phase equipment up to their rated output. PhaseP erfect does need periodic capacitors changed, RPC may need the electrolytic start capacitor periodically changed.
www.phaseperfect.com

PTS003 - 3HP 230V Digital Phase Converter - Phase Perfect® Simple

www.phaseperfect.com www.phaseperfect.com
www.phaseperfect.com

PTS005 - 5HP 230V Digital Phase Converter - Phase Perfect® Simple

www.phaseperfect.com www.phaseperfect.com
 
I've owned a Phase Perfect for 18 years. I routinely say that it has been the most reliable piece of equipment in my shop that runs off electricity. I upgraded from a rotary unit and have never looked back. Now, in my case, I have several 3-phase machines that range from 2 to 13 HP, so I can more easily justify the cost of the PP.
 
I've been running a GWM rotary for at least 20 years. At that time, and perhaps still, a solid-state phase converter could damage the motor if you tried to run it at full load. A rotary would not. Rotaries are noisier if that's an issue for you. Like mksj said, VFDs seem to be the most popular method if you're only going to power a single machine. (Careful! Machines have a way of multiplying...)

GsT
 
Calandrod said:
I just asked this in GJ, but I’m thinking some people here might have good insights specifically related to the hobby.

So I am going to buy a small 5hp phase converter to run my 1.5hp Bridgeport. I have done some research into American Rotary Phase Converters and they use Baldor motors which I like, have a great warranty, have great customer service, and overall it seems like a very quality product. I’ve spent a long time talking to them and they have been helpful in figuring out what I need. The model I’ve been looking at is the ADX-5.

My father in law does a lot of electrical for his business and he likes the digital phase converters, specifically recommending the 5hp Phase Perfect digital converter.

Does anyone recommend one either way? They are equally priced so longevity and quality are main concerns. Thanks!
Click to expand...

For my 3 Ph 550v surface grinder with 5 motors I use this:

7.5 HP and 15 KVA 3 ph transformer used $1300 CAD

stand.PNG

For my lowly bridgeport with just a single 220v 2HP 3ph motor I use this:

Chinese 2HP VFD $110 CAD

IMG_20221101_181144426.jpg

Oh and I put a TECO L510 VFD on the lathe...

Take from this what you will
 
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Not having any 3 phase equipment, I am probably the least appropriate input for a hobbyist. However, I am a retired industrial electrician, electronicist, and part time engineer. In that I was not hired as an engineer, but have designed electrical and electronic installations for the mills I have worked at. For 50 odd years I have had to deal with variable speed and frequency controlled devices. Until the turn of the century, variable speed meant DC motors, period.

Having dealt with variable frequency (variable speed, Reliance) drives, I do not approve of them in an industrial environment unless there is no other solution. In the case I am thinking of, the motors were paired 50 HP motors, each with a seperate drive. The requirements of the install are not appropriate here, just that they had to adjust the final load in real time.

While the drives were the responsibility of the electricians, whenever a problem arose with them the usual response was to scream for an electrical engineer. This from (reasonably) qualified industrial electricians. Conceded, much of the trouble was electricians that would have preferred to sit in their shop and drink coffee rather than learning new ways to do things. For this reason, I stand against any electronics for electrical devices.

Most anyone, "electrician or wannabe", can deal with a rotary converter. It is a simple device that dates back over a hundred years. It can be built up by a novice, with few parts. VFDs are wonderful devices but have many, many adjustments that even electricians do not fully comprehend. They will work, but when something doesn't do what was planned, going to the manufacturer is the only acceptable response. A good electrician can help, but in most cases needs to read poorly translated documents for often hours to grasp whether the problem is misadjustment or malfunction.

Finished rant
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I run an American Rotary AR-5 for my mill and drill press, and an AR-20 for my lathe. What I like about rotary is you get to wire and run your machine on 3-phase as it was intended to, true WYSIWYG operation. No splitting out machine circuits for VFD, no butchering up your OEM electrical box, no need to leave schematics and instructions for future owners in your post-mortem. And the noise isn't too bad, it's all Baldor gear after all.
 
Another satisfied Phase Perfect owner, though I would not go to the expense involved for powering just one machine. For powering a single milling machine, it'd be a VFD for me, hands down. Used one on my previous mill for ten trouble free years, it's still working perfectly for it's new owner. Maybe VFD's and "Digital" phase converters used to be unreliable, but those days are long gone. Used extensively in the HVAC, petroleum, and elevator industries, with excellent results.
 
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