Which brand phase converter to purchase

[Jakedaawg]

Nice, what are you doing on here though? This time of year you should be winterizing and shrink wrapping like a mad man....

One of my friends just opened a new facility in Leelaunau county, one of the best businesses to be in where you're at


John

Yes, im in leelanau. Almost done with the boats. 1 wrap and 2 repairs togo. Haven't had a day off since labor day. I got lucky and the weather was bad so most of my folks came off the lake early. I try to get 4-6 winterized and wrapped each day. I'm a one man shop with only 200 or so customers that mostly store inside. Only 60 wraps.

 

[Jakedaawg]

I have made several (7 I think) rotary phase converters over the years... They're so easy to make that I feel a little sheepish saying that I made them.
Finding an old 3 phase motor in good condition of almost any size is easy enough.
Buying the run capacitors and tuning it is easy enough... The most recent one that I built included a box with separate cap banks for each phase, and brought caps in and out with regular AC light switches to get the best balance between flat voltage and low amperage.

I went with a 25HP rotary for a few reasons...
1. Have to start some big motors. That's the obvious.
2. Start with a pony motor (5HP) and then close in the 25HP with a contactor, so don't worry about start surge of a 25HP.
3. Running amps on my unloaded 25HP motor can be tuned (with capacitors) down to 3-4 amps.

My first rotary phase converter - can't even include that in the "built" list. It was a 10 HP 1760 RPM that I'd spin up with a corded drill to about the right speed and close an old breaker... It would bang into phase and I'd have unbalanced 3 phase. Occasionally I'd mis-guess the speed and close the breaker to an immediate trip.
I ran that thing unbalanced for 10 years or more and close to capacity. All machines that I ran off that old 10HP continue to run to this day without a hiccup. If I had thrown a clamp on ammeter on the phases I probably wouldn't have run that way longer than it would have taken me to build the balance box.
I include that old 10HP story to illustrate how easy it can be improved on... Not as a recommendation. I did a lot of really stupid things in my 20's that I wouldn't do again if I had the means to do better.

Do you have a how to thread? I'm not scared to try.

 

[JimDawson]

Do you have a how to thread? I'm not scared to try.

This is a long thread, but has a lot of DYI RPC information https://www.hobby-machinist.com/threads/another-rotary-phase-converter.63204/#post-520986

 

[Papa Charlie]

Do you have a how to thread? I'm not scared to try.

I would be very interested in this as well.

 

[ACHiPo]

One caveat--torque motors (all motors designed to move things) are not efficient as RPCs. They definitely work, and if you have plenty of current available it's probably not a problem. I was limited to 20A for my 10HP RPC and it starts and runs fine because the generator and controller were designed to generate 3 phase power from single phase. I would probably need 25-30A to use a regular 10 HP 3-phase motor as a DIY RPC.

Phase Converters 101

What is a phase converter? You've come to a great place to Start... How does a phase converter work and what size is most appropriate for my application? These are the two most common questions asked. Phase Converters Phase Conversion

www.northamericaphaseconverters.com

What is a Rotary Phase Converter & Other Rotary FAQs

Rotary Phase Converter General Questions What is a rotary phase converter? A rotary phase converter is an efficient way to produce 3 phase power from a single phase power source. It generates one line from a generator motor and combines that with your two single phase lines. What does CNC...

www.northamericaphaseconverters.com

Give North America Phase Converters a call. They are very knowledgeable and helpful.

 

[Jakedaawg]

One caveat--torque motors (all motors designed to move things) are not efficient as RPCs. They definitely work, and if you have plenty of current available it's probably not a problem. I was limited to 20A for my 10HP RPC and it starts and runs fine because the generator and controller were designed to generate 3 phase power from single phase. I would probably need 25-30A to use a regular 10 HP 3-phase motor as a DIY RPC.

Phase Converters 101

What is a phase converter? You've come to a great place to Start... How does a phase converter work and what size is most appropriate for my application? These are the two most common questions asked. Phase Converters Phase Conversion

www.northamericaphaseconverters.com

What is a Rotary Phase Converter & Other Rotary FAQs

Rotary Phase Converter General Questions What is a rotary phase converter? A rotary phase converter is an efficient way to produce 3 phase power from a single phase power source. It generates one line from a generator motor and combines that with your two single phase lines. What does CNC...

www.northamericaphaseconverters.com

Give North America Phase Converters a call. They are very knowledgeable and helpful.

So, you are.stating that the driven motor in a rotary phase converter is different than a typical 3 phase motor one would use in a home built rotaryphase converter? What are the differences? Is it in the windings and such or the frame and bearings? Would you expand on this please?

 

[ACHiPo]

So, you are.stating that the driven motor in a rotary phase converter is different than a typical 3 phase motor one would use in a home built rotaryphase converter? What are the differences? Is it in the windings and such or the frame and bearings? Would you expand on this please?

The motors North America Phase Converters use are custom-built by Baldor to be optimized for 3-phase generation. As I recall the windings and frame are both different from a standard 3-phase motor designed for torque. The starting/filtering caps are also optimized for the application. I talked to the president of the company and he explained the differences to me, but that was a while ago and I don't remember the details. I do know that Ulma Doctor was amazed at the efficiency I was able to get from the 10 HP RPC--he expected that I would need a much bigger breaker to get the motor started.

I'd suggest giving them a call if you have technical questions. They are just across the lake from you in the Milwaukee area.

Sorry I'm not more help.

 

[Jakedaawg]

Thanks for the reply. It seems that in these purchased rotary converters there are not two motors? One single phase driving a three phase? I guess they spin a single 3 phase generator motor on two phases at reduced power and the third phase is produced and then a controller unit times the phases? Man, there are some wicked smart folks out there.

 

[ACHiPo]

Thanks for the reply. It seems that in these purchased rotary converters there are not two motors? One single phase driving a three phase? I guess they spin a single 3 phase generator motor on two phases at reduced power and the third phase is produced and then a controller unit times the phases? Man, there are some wicked smart folks out there.

Both NAPC and American Rotary use electronics to get the 3-phase motor spinning instead of a second "pony" motor.

 

[Jakedaawg]

Well, they are dropping the new ADX 20 by American Rotary here at the shop today. This will be much less expensive than having a 3 phase drop from the pole.

I ordered yesterday morning fornthe cyber Monday event discount and its here by noon today. Long way around the lake. I will be impressed.

Now I just got to get the fork lift fired up.