Rotary Phase Converter Question for Newbie

I just got off the phone with Dave Kwasny from North American Phase Converter. He spent 20 minutes with me on the phone talking about phase converters and different options. We also discussed building one and just buying the control panel from them. Very informative. I will be buying from North American Phase Converter instead.

Also, I'm not opposed to using a VFD, my problem is I really don't know much about them. I've heard that you have to be good at programming too? I am going to look into them as well to learn more.
 
bnelson1980 said:
I've order the parts to complete my Sharp LMV 50 Mill. The 3HP 3 Phase motor arrives next week. I called American Rotary to order a Rotary Phase Converter. I almost pulled the trigger, but wanted to check with you all to get your advice and make sure I am not going overboard with what American Rotary is saying I need.

They said that because it's a 3HP 3 Phase Mill I would need there 7.5HP AD Rotary Phase Converter. I also need the 3 phase breaker which is $99 and a couple other plugs and receptacles. Comes out to almost $1,200 for the Rotary Phase Converter setup. Seems kind of high to me? If that is what I need, then I will buy it. I just want to make sure I am not being taken advantage of.

Thanks!
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I think they're quoting you a price for a top of the line system. In a perfect world where money is of no concern it would be the "best" way to go. However since money can be a concern I think you can get by with a much less expensive system. Personally I would consider a static converter (at least as a temporary solution) if finances won't allow you to purchase a rotary one.

I have 3 machines in the shop powered by static phase converters. A 1.5 hp Bridgeport mill, a 1.5 hp Racine power hacksaw, and a 2 hp Sheldon lathe. They are all using 1-3 hp static converters. The mill has an older Phase a Matic, and the saw and lathe have American Rotary's. The mill has been running on the Phase a Matic for about 15 years. The other two machines have been on the American Rotary converters for a couple years

My intention is to in time convert the entire shop to a 15 hp American Rotary brand rotary phase converter. I have all the hardware in stock, but need to get another sub panel installed before hooking up the system.

A 1-5 hp American Rotary static converter costs less than $200.00.
https://www.wolfautomation.com/inde...MI4OrMgL-62QIVQbnACh3gKwKTEAAYASAAEgJvu_D_BwE

The only disadvantage is that the machines will run at about 2/3 the rated hp. The system only generates the third phase (using capacitors) for a few seconds during startup. Once the machine is running it's essentially on single phase. I have never had a situation with any of these machines where running below the rated hp was a problem. I have worked all of them hard for as many as 10 hours at a time with no problems.

American Rotary has made over 3400 sales from their eBay store. The only complaint I found was someone who was unhappy that they needed to pay the transportation company an extra $50.00 to have a unit delivered by a truck with a lift gate. Personally I can't believe eBay allowed a comment that should have been directed to the trucking company to influence the rating of a seller.
 
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Nothing special about the LMV-50 that you need a CNC rated RPC, it is considered and easy start load. Typically for CNC you need a RPC 2X the rated Hp of the load and better leg to leg voltage control. I have a LCM-42 (LMV-42) so I am familiar with the mills, I purchased mine with the digital head and VFD, the control system is extensively modified. The base mill is about as basic (i.e. no circuity or semiconductors) as you can get, so any RPC would work. I agree, that a 7.5 Hp RPC might be a better choice only if you think you will be running more than one machine or might have equipment down the line that would need a larger RPC. My friend had a Phase-Craft RPC control system with a custom 7.5Hp idler motor, he routinely starts 5Hp motors with ease. You also need to consider your available 240VAC service for the size RPC you are using, not sure but probably need a 50-60A breaker for 7.5Hp, 30-40A for 5Hp. RPC's can also be a bit noisier, seems to be a wide variation so something to check. Better quality units use a 1750 RPM idler motor should be quieter, but something to factor in the decision process.

The Teco L-510 is very simple and easy to program, I can put together a parameter file if you have the motor nameplate info and how you want to control the VFD inputs. I recommend 3 wire control, pick up a few switches from Automation Direct and put them in a small box. I recommend 3 wire control which uses a momentary push button for stop, a momentary push button for start, and a sustained switch for forward/reverse. Download the manual, 99% of the parameters are not touched. The motor is directly wired to the VFD, no switches. At $200, I recommend it over the other options if you only need 3 phase for one machine. You also get soft start, braking and variable speed. VFDs go not play nice with GFI's so if you have one, then go with a 5Hp RPC if just running the LMV-50.

3 wire control.jpg
 
I started out with an American Rotary AR5 but had to upgrade for my lathe which is 5hp. I went to a AD10 with the intention of adding a 5hp cnc mill.
Now my air compressor is getting tired and parts are no longer available to rebuild the compressor. It is not quite large enough for sandblasting large items so I'm planning on going to a 7.5 hp 3 phase compressor.
Which presents another problem requiring me to upgrade my RPC again.
It's hard to see into the future but if you plan to add more equipment it would be a lot cheaper in the long run to get a larger power source at the beginning.
Think about equipment you might add and look at the largest hp required and adjust accordingly.
I like to have the capability of running 2 machines when possible.
 
Go VFD. You get simple, cheap, quiet and small footprint as well as speed control. RPC's are old tech.
 
I'm running the cheap unbranded 3ph converters/VFD's out of China. Ebay has them occasionally, mine have lasted for years. I don't think mine are still sold, but they are cheap enough to put one on each 3ph machine. Even the little $100 1.5 kw 220 volt converter has lasted over 6 years now. I figured out the chinglish manuals, it makes sense after a few beers. They are cheap enough to keep a spare, but I haven't had one fail yet.
 
I built my 10 hp rotary and my balance as it stands now is AB 236 AC 238 BC 142 . My question is if that looks good to go even though I can probably do better but is that ok to go . Any one with experience on this subject of balance?
 
Eli said:
I built my 10 hp rotary and my balance as it stands now is AB 236 AC 238 BC 142 . My question is if that looks good to go even though I can probably do better but is that ok to go . Any one with experience on this subject of balance?
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Sorry last one is 242 not 142
 
I have been starting a 7.5hp Redstar Radial Arm Saw with a home built balanced RPC using a 10hp idler motor for 20+ years. Yes, a RAS has a very low starting load.

AB 236 AC 238 BC 242 - Is very well balanced! Much better than most RPC's that I have come across. My balanced RPC has a variance of about 15v across the different legs and I consider it very well balanced too.

I HIGHLY recommend installing one of these 3 phase panel meters in any RPC. https://www.amazon.com/Three-Phase-...3+phase+panel+voltmeter&qid=1634267355&sr=8-2
611ABpYJz4L._SL1001_.jpg
I doesn't give you any information that you really need to worry about when you are running your 3 phase machines... BUT THEY LOOK REALLY IMPRESIVE for about $35!
 
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MikeInOr said:
I have been starting a 7.5hp Redstar Radial Arm Saw with a home built balanced RPC using a 10hp idler motor for 20+ years. Yes, a RAS has a very low starting load.

AB 236 AC 238 BC 242 - Is very well balanced! Much better than most RPC's that I have come across. My balanced RPC has a variance of about 15v across the different legs and I consider it very well balanced too.

I HIGHLY recommend installing one of these 3 phase panel meters in any RPC. https://www.amazon.com/Three-Phase-...3+phase+panel+voltmeter&qid=1634267355&sr=8-2
View attachment 382099
I doesn't give you any information that you really need to worry about when you are running your 3 phase machines... BUT THEY LOOK REALLY IMPRESIVE for about $35!
Click to expand...
Lol thank you so much I’m sure going to get one for visuals sake . Like you said it sure looks good.
 
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