Rotary Phase Converter Suggestions

[ovrrdrive]

I don't really know anything about these but I need to buy one to run a sander we just bought for the shop. It's a 3PH 15HP 230/3/60 motor on it that draws 48A. My understanding is I need a 25HP RPC to power it. What brands and features should I be looking for?

Any suggestions or ideas will be appreciated. Thanks.

 

[BLUE72CAMARO]

I put a 10hp american rotary in my shop to cover my 3hp lathe and a future bridgeport purchase at the same time. But that is obviously a lot smaller than what you are looking at so my recommendation would be to call American rotary as there tech support was top notch when I talked with them.

 

[APEowner]

I've been very pleased with my American Rotary.

 

[930dreamer]

http://www.phaseperfect.com/p/t/specifications

 

[Daves69]

http://www.speedy3phase.com/ is the company I purchased from.running a 7 hp lathe and a mill off of it working great.

 

[ovrrdrive]

Thanks for the suggestions. They seem pretty straight forward.

 

[bjcouche]

15HP is awful lot to be placing on a 240V single phase residential service.... Your 48A 230V 3 phase motor calculates to (230*48*1.732)/240= 80A. Hopefully you have a larger service than 200A....

Anyhow, Normally I would recommend a VFD (Variable Frequency Drive, inverter, etc.) However at 15HP and 240V single phase, that get's big and expensive quick. I wouldn't recommend a static nor rotary phase converter either for many reasons, unless you like doing things the the way your great grandfather did for nostalgia purposes.

The phase perfect units are basically a vfd in a box with some type of output filtering. A big advantage is that they are designed and engineered for you and everything is in the box. I'd look into the phase perfect units or other digital phase converter options for 15HP.

Brian

 

[930dreamer]

Just build two rpc, that's what I did. I started with a 10 hp and could add the 7.5 hp, I never needed both for a machine but would use them to test larger motors.

 

[Matt Matt]

How many motors does the sander have???

- A Vfd is one solution. At about $1000
- A capacitor start, is a second solution added to a already in service RPC. Less than $200
- A Second RPC to stiffen the third leg. But, just another machine online and running could do almost the same thing.
- A phase perfect 30 hp on 100 amp SP circuit for about $3500.

I am running a 5 hp, 20 hp RPC to achieve voltage requirements, as I use ******’s to step up to 600 . RPCs are pretty much bulletproof, and you can build them yourself for almost scrap up prices.

I also have four VFD‘s and have installed hundreds.

 

[86turbodsl]

15HP is awful lot to be placing on a 240V single phase residential service.... Your 48A 230V 3 phase motor calculates to (230*48*1.732)/240= 80A. Hopefully you have a larger service than 200A....

Anyhow, Normally I would recommend a VFD (Variable Frequency Drive, inverter, etc.) However at 15HP and 240V single phase, that get's big and expensive quick. I wouldn't recommend a static nor rotary phase converter either for many reasons, unless you like doing things the the way your great grandfather did for nostalgia purposes.

The phase perfect units are basically a vfd in a box with some type of output filtering. A big advantage is that they are designed and engineered for you and everything is in the box. I'd look into the phase perfect units or other digital phase converter options for 15HP.

Brian

While it may be old tech, an RPC will do a fine job of providing 3 phase for hobbyist shop without incurring the LARGE cost of a phase perfect. There's tons of guys using rpcs around the world. And a 200A service will support quite a large RPC. Especially if pony started.

I'd encourage the OP to visit practicalmachinist VFD/RPC forum for more solid advice and not worry too much about the above.

(And i run a 20HP rpc on my 200A shop service on a 100A breaker, which is oversized a bit from the 80A one it really needs.)

 

[7635tools]

I run a 40hp RPC off my 200A service and I’ve had zero issues. I used to use drives to get 3 phase but the cnc lathe doesn’t like the “dirty” power from the drive so in went the RPC and a 100A panel for all the 3 phase machines.


Sent from my iPhone using Tapatalk

 

[ovrrdrive]

I dug into these deeper and after doing some research and considering this would be running on my 150A service in my garage at home - while the home is still being lived in - I chickened out and told the sales person to change my order to the single phase version instead of the 3 phase. The 3ph version has a 15hp motor but the single phase has a 10hp, that's the only difference. At first the salesman told me the 3ph version would be more efficient and use a lot less energy than the single phase would. Everything I am reading points to the contrary. They are supposed to run very similar torque wise and they claim the single phase version will work as well as the 3ph will.

The main drawback is they will take about 2 months longer to9 ship the single phase version to me. For my use, especially considering it will be in my garage at home I am thinking the single phase version will be the better choice for us. Hopefully I'm not wrong about that. And I get to keep my $2500 I would have used on the rpc too.

 

[firebirdparts]

Good idea. That's a heck of a machine to run on a RPC. I don't know anybody who has one that big.

 

[Bert_]

Good idea. That's a heck of a machine to run on a RPC. I don't know anybody who has one that big.

Service size is the only limitation. Just last week I wired a grain dryer with a 75hp blower to a phase converter. I was a little skeptical since the converter was only rated for 60 hp as the largest motor but run up to 120hp total. With a little tweaking it is running fine. Phase converter was a phase a matic that's about 20 years old, rated 533A single phase input and 308A 3 phase output at full load.

It's not ideal but when 3 phase primary is miles away, it is by far the cheaper option.

 

[Matt Matt]

Service size is the only limitation. Just last week I wired a grain dryer with a 75hp blower to a phase converter. I was a little skeptical since the converter was only rated for 60 hp as the largest motor but run up to 120hp total. With a little tweaking it is running fine. Phase converter was a phase a matic that's about 20 years old, rated 533A single phase input and 308A 3 phase output at full load.

It's not ideal but when 3 phase primary is miles away, it is by far the cheaper option.

interesting. Do you have any pictures?

 

[86turbodsl]

I dug into these deeper and after doing some research and considering this would be running on my 150A service in my garage at home - while the home is still being lived in - I chickened out and told the sales person to change my order to the single phase version instead of the 3 phase. The 3ph version has a 15hp motor but the single phase has a 10hp, that's the only difference. At first the salesman told me the 3ph version would be more efficient and use a lot less energy than the single phase would. Everything I am reading points to the contrary. They are supposed to run very similar torque wise and they claim the single phase version will work as well as the 3ph will.

The main drawback is they will take about 2 months longer to9 ship the single phase version to me. For my use, especially considering it will be in my garage at home I am thinking the single phase version will be the better choice for us. Hopefully I'm not wrong about that. And I get to keep my $2500 I would have used on the rpc too.

2 things here:

1. 10HP single phase motors don't have a stellar record for longevity. I'm not sure why.
2. $2500 for a RPC big enough to run this thing is highway robbery, unless the company selling it to you will be paying for your next vacation to vegas or wherever. I have $37 into my motor for my rpc, and surplus everything else is maybe $150. I suppose you could spend like $500-1000 if you paid to have it all done for you.

 

[ovrrdrive]

2 things here:

1. 10HP single phase motors don't have a stellar record for longevity. I'm not sure why.
2. $2500 for a RPC big enough to run this thing is highway robbery, unless the company selling it to you will be paying for your next vacation to vegas or wherever. I have $37 into my motor for my rpc, and surplus everything else is maybe $150. I suppose you could spend like $500-1000 if you paid to have it all done for you.

I'm not thrilled to hear that about the 10hp singles but the change order is already set so that is what I am getting now. I guess the bright side is they should be easy to source and replace if and when it shits the bed.

American Rotary 25hp rpc's run between $2000-2300 depending on options. There's no way I would risk trying to make something I know nothing about with a $14000 sander. It would be safer for me to pay what they are asking for them.

 

[Bert_]

I haven't seen a lot of issues with the 10hp single phase motors. No more than smaller motors anyway. I have seen some problems with 15hp single phase motors when they have a high inertia or hard starting load.

interesting. Do you have any pictures?

Not at the moment. Next time I'm there I will take a couple.

 

[Matt Matt]

Not at the moment. Next time I'm there I will take a couple.

Thanks. My supplier will build me almost size Single phase VFD. But, for distribution, nothing beats a RPC. I have a portable 20 hp. RPC that has 240 V three-phase and 600 V three-phase all generated off of a 50a welding plug. When I say portable, it’s on a dolly. It does way over 400 pounds.

 

[86turbodsl]

I haven't seen a lot of issues with the 10hp single phase motors. No more than smaller motors anyway.

I've read a few threads over on practicalmachinist about 10hp motors being a problem over the years. the OP can go research it if he wishes. 10HP 1ph motors are NOT very common. That's a BIG motor for single. 15hp single, i've never even laid eyes on one. When you're getting up to the 10hp range, i always reach for the 3ph motor.

 

[79firebird]

10 hp single phase are very common where im at most shops here that dont have 3 phase run 10 hp . my old works compressor ran on a 10 hp motor tell the head blew so we replaced the head. 18 years in use now running 16 hours a day non stop 5-6 days a week. replaced the cap a fue times and thats it.