choosing a 3 phase rotary converter

Starting to shop for a 3 phase converter. I was planning on a 7.5hp. I have one sb lathe with a 2ph motor, and a bridgeport mill that is currently 1hp, but i may go 1.5 or 2 hp later, undecided. Also have another sb that will probably be 2hp as well, but i cant forsee running two lathes at once. More than likely will only ever run one machine at a time, at most two, but infrequently.

Anyway i have been eyeballing a couple of vendors on ebay and was curious if anyone has experienced their stuff or have any other useful opinions. The two companies are American Rotary and North American. American Rotary offers basically a standard controls 7.5hp at a lower cost, or a digital control setup thats a little bit more costly. I have mixed feelings about digital controls. Great when they work, a pain if they blow control boards often. Any insights appreciated.

American Rotary basic controler:
American Rotary Phase Converter AR7 7.5HP 1 to 3 Three PH Heavy Duty CNC USA | eBay

American Rotary Digital Controller:
Rotary Phase Converter AD7 Digital Controls Heavy Duty HD CNC USA Made | eBay

North American:
PL-7 Pro-Line 7.5HP Rotary Phase Converter - Built-In Starter, Made In USA

American Rotary sponsors Keith Rucker's U-Tube channel and he has one of their large units, and seems very happy with them and their products. He might be responsive to an email if you want to ask him. [email protected]

Look up Phasecraft, he sells on eBay but is also a member here. You supply your own idler motor he supplies the rest. With his help I put together a 7.5hp rpc for about $250.

Blob said:

American Rotary sponsors Keith Rucker's U-Tube channel and he has one of their large units, and seems very happy with them and their products. He might be responsive to an email if you want to ask him. [email protected]

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I purchased an American Rotary AR-15 last year and could not possibly be any happier. I wired it into a 3-phase MLO panel with 4 breaker spaces and I can run up to 4 different machines, just not all at the same time depending on draw.

Remember to get double the HP you need to run. My lathe is a 7.5hp so I needed a 15hp rotary.

American Rotary contacted me immediately after I made the purchase just to double check that everything was up to spec and would handle my needs. They shipped FedEx Freight and I had it in 2 days. They also contacted me after I had the unit for a few days to make sure the install went okay. You can't beat that kind of customer service.

Or if you want a winner, Phase Perfect

Mine has been a little north of you for 12 years with ZERO issues and no rotating parts (other than the pair of fans)

texasgunsmith said:

Starting to shop for a 3 phase converter. I was planning on a 7.5hp. I have one sb lathe with a 2ph motor, and a bridgeport mill that is currently 1hp, but i may go 1.5 or 2 hp later, undecided. Also have another sb that will probably be 2hp as well, but i cant forsee running two lathes at once. More than likely will only ever run one machine at a time, at most two, but infrequently.

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Your requirements are in the 5Hp category. A 7.5Hp sounds more manly, but it's a waste.

Ask about the quality of the internal components, capacitors etc. Some are made in US and some in China. Not that US is better but easy to save $100 on parts inside and not have an apples to apples comparison. The motor quality is also a big deal. All will tell you their motors are special made but still good to ask for specifics. Kay and Arco are slightly different and I believe use only run capacitors. They size their units by how large the highest starting motor can be so a 5 hp Kay is close to a 10 hp Am Rotary. Your machines are fairly close in hp so balancing should be easier than if they were a wide range. If you find a used Phase Perfect ( white one ) you should consider it. More than what you need today but quiet, balanced power, and cheap to run. Dave

Personally speaking, I would go with VFDs on machines that are 3HP or less, since the cost of VFDs is not too bad for that size, and they are fairly quiet, more so than a RPC. The cost a VFD starts to go up considerably when you go over 3HP.

I have a 7.5HP RPC that I use on my 5HP machines, but the smaller ones can use a VFD.

I agree with JohnO, Phase Perfect is a winner, but only if cost is not a strict factor. This is what I plan for my new shop I will be building at some point, unless the power company has 3 phase at the property, but I seriously doubt it and am preparing to get a Phase Perfect.

Blob said:

American Rotary sponsors Keith Rucker's U-Tube channel and he has one of their large units, and seems very happy with them and their products. He might be responsive to an email if you want to ask him. [email protected]

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American Rotary also has some nice vids of their own.

hsracer201 said:

I purchased an American Rotary AR-15 last year and could not possibly be any happier. I wired it into a 3-phase MLO panel with 4 breaker spaces and I can run up to 4 different machines, just not all at the same time depending on draw.

Remember to get double the HP you need to run. My lathe is a 7.5hp so I needed a 15hp rotary.

American Rotary contacted me immediately after I made the purchase just to double check that everything was up to spec and would handle my needs. They shipped FedEx Freight and I had it in 2 days. They also contacted me after I had the unit for a few days to make sure the install went okay. You can't beat that kind of customer service.

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You know I keep hearing good things about American Rotary. I've installed a nice service panel my shop, and I have been thinking I will use a wall mount control panel for the converter close to the service panel. Then install three 3 phase outlets at 3 different location inside of shop. Without all the parts in front of me I dont know yet, but I was thinking maybe another service panel for 3 phase or run all 3 outlets from the converter with each outlet or machine having its own breaker. I think I will probably go overkill, with breakers directly from phase converter as well as directly at machine or outlet.

johnoder said:

Or if you want a winner, Phase Perfect

Mine has been a little north of you for 12 years with ZERO issues and no rotating parts (other than the pair of fans)

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From your post I checked out their website. Very nice, looks like high tech stuff. No prices listed, but I'm guessing its more than my needs.

rons said:

Your requirements are in the 5Hp category. A 7.5Hp sounds more manly, but it's a waste.

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I agree. For quite a while my every intention was a 5hp. Then I got a milling machine. And while I think 5hp is still probably enough for me, I typically find when building electrical systems close to spec that all too often any future add ons, upgrades, or other changes require more power, never less, lol. I see it pretty often with power generation on boats and shipping. They install gen sets and electrical systems for x amount of kw. Then a year or two later they want to add motors or heavier electronics that the current setup does not handle. Already I'm thinking of whether to do single or 3 phase cooling pumps, lol. Or if the right 3 phase drill press fell into my lap, haha.

traditional-tools said:

Personally speaking, I would go with VFDs on machines that are 3HP or less, since the cost of VFDs is not too bad for that size, and they are fairly quiet, more so than a RPC. The cost a VFD starts to go up considerably when you go over 3HP.

I have a 7.5HP RPC that I use on my 5HP machines, but the smaller ones can use a VFD.

I agree with JohnO, Phase Perfect is a winner, but only if cost is not a strict factor. This is what I plan for my new shop I will be building at some point, unless the power company has 3 phase at the property, but I seriously doubt it and am preparing to get a Phase Perfect.

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Early on I was thinking of going VFD. After doing a mindnumbing amount of reading I decided on rotary, though I can't personally justify why in tech terms, other than it appeared to me rotary can handle motor starting and increased loads better from the specs I was reading.

Adwcali said:

Look up Phasecraft, he sells on eBay but is also a member here. You supply your own idler motor he supplies the rest. With his help I put together a 7.5hp rpc for about $250.

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Your post provided me with today's learning experience. I did not know what you meant by idler motor. In reading, his add on ebay was educational. My assumption was the motor in rotary converters was in fact two motors in a single case, with a single phase motor driving a 3 phase motor to create power generation. Apparently I was wrong and his advert explains that. I also am intrigued by using a 34xx rpm motor, as well as choosing my own motor, which nice quality motors can be found reasonably priced, I really like that. It also explains why the other companies offer just the control panels. I think I am going to look closer at these control panels to see which parts etc I like.

Steve Watkins is less than 100 miles north and as near as I know has used Phasecraft on his 20HP RPC. You may want to see if he would welcome a visit

Here is a related thread - Steve refers to it as Phase-Craft

http://www.practicalmachinist.com/v...ford-planer-beast-317291/?highlight=converter

texasgunsmith said:

Your post provided me with today's learning experience. I did not know what you meant by idler motor. In reading, his add on ebay was educational. My assumption was the motor in rotary converters was in fact two motors in a single case, with a single phase motor driving a 3 phase motor to create power generation. Apparently I was wrong and his advert explains that. I also am intrigued by using a 34xx rpm motor, as well as choosing my own motor, which nice quality motors can be found reasonably priced, I really like that. It also explains why the other companies offer just the control panels. I think I am going to look closer at these control panels to see which parts etc I like.

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Jim aka Phasecraft is a really nice guy to visit with on the phone. He was able to answer all of my questions and fix me up with exactly what I needed. Give him a call it'll be worth your time.

Adwcali said:

Jim aka Phasecraft is a really nice guy to visit with on the phone. He was able to answer all of my questions and fix me up with exactly what I needed. Give him a call it'll be worth your time.

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I have a 20hp rpc that I setup using my own idler motor and a control box from Jim at Phase-craft. He was very helpful with the setup, answered all my questions and always picked up the phone when I called. His phone # (714)710-9094

Here is a thread I started regarding my setup.

http://www.practicalmachinist.com/v...tup-my-20hp-rpc-3ph-panel-330090/#post2904072

texasgunsmith said:

Early on I was thinking of going VFD. After doing a mindnumbing amount of reading I decided on rotary, though I can't personally justify why in tech terms, other than it appeared to me rotary can handle motor starting and increased loads better from the specs I was reading.

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Interesting. I have both an RPC and VFD, and I prefer to use the VFD as it's quieter and I don't have to listen to the idler motor. Mine has the arbor cut off, and is tailored to being used in an RPC, but it still makes some noise, it is a motor running after all. Yes, people build boxes around them, and ventilate the boxes, and sound proof them as well...that does help some, but even if you don't hear much of the noise, you can feel the vibration. A motor is running.

Certainly we all have our own opinion, so not trying to sway you one way or the other. I was just saying for me personally, I would rather use a VFD than an RPC. I would much prefer to use a Phase Perfect, it is completely quiet and acts just like genuine 3 phase, AFAIK. You will notice that all RPCs have one leg that is slightly lower.

traditional-tools said:

Interesting. I have both an RPC and VFD, and I prefer to use the VFD as it's quieter and I don't have to listen to the idler motor. Mine has the arbor cut off, and is tailored to being used in an RPC, but it still makes some noise, it is a motor running after all. Yes, people build boxes around them, and ventilate the boxes, and sound proof them as well...that does help some, but even if you don't hear much of the noise, you can feel the vibration. A motor is running.

Certainly we all have our own opinion, so not trying to sway you one way or the other. I was just saying for me personally, I would rather use a VFD than an RPC. I would much prefer to use a Phase Perfect, it is completely quiet and acts just like genuine 3 phase, AFAIK. You will notice that all RPCs have one leg that is slightly lower.

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I can definitely dig what your saying about noise. I set up a bunch of over head lights and I'm about to shit can one and replace it with another new one as it has a minor buzzing sound, lol. As far as the rpc, i'm really hoping i get a quiet motor, some are nearly dead quiet with no physical load attached, and some really make some noise. Sadly I wont know till the money flies out the door. My thinking is it'll be running when machines are going and they'll be making more racket than the the idle motor.

johnoder said:

Steve Watkins is less than 100 miles north and as near as I know has used Phasecraft on his 20HP RPC. You may want to see if he would welcome a visit

Here is a related thread - Steve refers to it as Phase-Craft

http://www.practicalmachinist.com/v...ford-planer-beast-317291/?highlight=converter

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Dude. Forget the RPC, I want to see his shop, lol. After your post I was checking out his vids. Wow that planer, and he's doing work to a bridgeport mill, which coincidently I will be tearing mine down to the ground once my lathe is done. I'm juggling way too many projects at home currently, but yea, I'd like to go have a visit when time permits.

There are ways to make an idler motor totally silent







Problem is I forget the darn thing is on now and once it ran for two days I've got to add a large signal light to warn me to turn it off when I'm not using it.....

swatkins said:

There are ways to make an idler motor totally silent

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Problem is I forget the darn thing is on now and once it ran for two days I've got to add a large signal light to warn me to turn it off when I'm not using it.....

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That is awesome ! Now that's thinking outside the box, or in this case, outside the building, haha.

I have had a 10-hp "HD/CNC Soft Start" American Rotary for about 11 years that I use to run a Deckel FP2NC and, lately, an Aciera F5. It has been reliable. American used a Baldor purpose-built rotary unit, which runs at 3600 RPM and is open drip-proof fan cooled. It is rather noisy in the relatively small space I have for my shop. (The Deckel electronics cabinet cooling fan is not much better.)

The main beef I have with American's electronics box is the awkwardness of making connections in the control box. The space is extremely cramped, and I have medium-size hands. The bus bars are rectangular aluminum extrusion, about 1/4 x 1 or so, glued through rectangular holes in a plastic (PVC?) panel separating the relay and cap compartment from the wiring compartment. The problem with the aluminum bus bars is that the connections are made with screws and nuts, rather than tapped holes in the aluminum, and the heads of the screws are practically impossible to reach to hold back the torque while tightening the nuts. Maybe I could have pulled out the entire guts of the unit from the box when making connections, but what a pain.

rklopp said:

I have had a 10-hp "HD/CNC Soft Start" American Rotary for about 11 years that I use to run a Deckel FP2NC and, lately, an Aciera F5. It has been reliable. American used a Baldor purpose-built rotary unit, which runs at 3600 RPM and is open drip-proof fan cooled. It is rather noisy in the relatively small space I have for my shop. (The Deckel electronics cabinet cooling fan is not much better.)

The main beef I have with American's electronics box is the awkwardness of making connections in the control box. The space is extremely cramped, and I have medium-size hands. The bus bars are rectangular aluminum extrusion, about 1/4 x 1 or so, glued through rectangular holes in a plastic (PVC?) panel separating the relay and cap compartment from the wiring compartment. The problem with the aluminum bus bars is that the connections are made with screws and nuts, rather than tapped holes in the aluminum, and the heads of the screws are practically impossible to reach to hold back the torque while tightening the nuts. Maybe I could have pulled out the entire guts of the unit from the box when making connections, but what a pain.

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This is what the inside of a Phase-Craft 20 HP control box looks like... Plenty of space, well marked and built with good components.





I like the separate control boxes because you can wire the box in a convenient place and put the idler motor wherever you wish. Here I have a 220 single phase sub panel on the right, Phase-Craft control box in the middle with a fused panel for protecting the idler motor on top, and a three phase breaker box on the left.



The other side of the shop has a Phase-Craft 10 HP system. This one has the idler motor up on the second floor and while it is not silent it is bearable.



The above system does not have a three phase panel. For that system I ran conduit from the Phase-Craft box around the walls to the different machines. It's a single 50 AMP circuit and wherever I needed a machine I inserted a fused disconnect for the correct amperage of each tool.. If the machine was 30 amp I put a 30 amp box there. While that works I soon found that I was spending a whole lot more for fuses and disconnects that I would ever have had for the 3 phase panel and breakers.

I buy the Phase-Craft boxes with the push button start on the side of the box. Need three phase, just push the button