# Which brand phase converter to purchase



## Jakedaawg (Oct 30, 2020)

Well, its time to pull the trigger on a phase converter for my Bridgeport 2hp.

What is the go to brand?  I know American rotary seems to dominate the market but are there others that are just as good?  It will be used a couple times a week, maybe more eventually.


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## projectnut (Oct 30, 2020)

I have several "American Rotary" static converters and they have been doing a fine job for over 5 years.   I also have a 10 hp American Rotary, rotary style converter that was supposed to replace all the static converters.  I went so far as to have a sub panel installed to power it.  However it's been setting under the bench for almost 5 years now.

I'm not sure if I'll ever install it.  The static converters seem to work well, and I'm not sure I want to spend the time, energy, and money for no foreseeable power or longevity advantage.  Projects seem to keep piling up rather than being completed.

As an FYI American Rotary no longer makes static converters.  A few years ago they bought out North America Phase Converter Co.  North America makes both static and rotary converters.  









						Static Phase Converters
					

Static Phase Converters   A static phase converter is used to generate 3 phase power during the starting of a motor.  A static phase converter consists of one or more start capacitors and a start relay.  The start capacitors produce electricity across the third winding of a motor during start up,




					www.northamericaphaseconverters.com


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## matthewsx (Oct 30, 2020)

I have a North American static phase converter bought earlier this year. Works fine for me, no hassle and powers my lathe without fail.

John


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## Ed ke6bnl (Oct 30, 2020)

I have a $100 static phase converter from ebay for about 3 years and a home made one for my drill press that has been going for about 15 years. All working fine


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## Cadillac STS (Oct 30, 2020)

Take a few different brands and do an internet search of each one first.  See which has good online support for programming it or with problems first.  Check which forums come up and how they answer questions for help.  Don't buy one that no one seems to know about because you have less options for help.


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## bill70j (Oct 30, 2020)

I bought a rotary phase converter for my mill from North American about 5 years ago.  It has been trouble free. 

Then when I got a larger lathe, I needed to up the capacity of the converter  and they helped me through the design for adding a second motor.  Very responsive and helpful technical folks.

I would definitely do business with them again.


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## JimDawson (Oct 30, 2020)

I would use a VFD if that is your only 3 phase machine.  Less money and quite reliable.  But stay away from the really cheap ones on Ebay and Amazon.  Teco and Automation Direct GS 3 units are very good.


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## pontiac428 (Oct 30, 2020)

I am impressed with American Rotary's quality.  Their support is good; I called them the other day about my options to increase output on my RPC in anticipation of a large lathe.  I can either gang two untis or replace and upgrade.  If I decide to replace mine with a bigger unit, I'll go through American Rotary again.


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## NCjeeper (Oct 30, 2020)

I have American Rotary Phase converters. Totally pleased with them. I have an old Phase-a-Matic static converter on my Doall bandsaw. It was on it when I bought it and works as it should.


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## MrWhoopee (Oct 30, 2020)

I purchased a WNY SPC from these people.


			WNY Supply Online store for static phase converters
		


It was well under $100, and intended to be a temporary solution until I received the 7.5 hp RPC that I'd been promised. After I received the RPC and used it for a while, I decided I didn't like the constant whine, and my wife didn't like the electric bill. I put the SPC back in service. No plans to replace it. If anyone wants the rotary, it's available.


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## Winegrower (Oct 30, 2020)

I use a Phase-A-Matic to drive the Bridgeport, Kalamazoo 9x16” saw, and Takisawa 14” lathe.   I have twist-lock connectors and just plug in whatever i’m using.    I’m with MrWhopee, the noise would drive me crazy and having it spinning all the time would just be quite unappealing to me.

The PAM has worked fine for each of these machines.


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## erikmannie (Oct 30, 2020)

I have an American Rotary AMP-10. It is as quiet as you will find, made in USA & it is on wheels so you can roll it out of your way (to sweep, e.g.).

Mine came with a 20A receptacle, and I am now adding a 30A receptacle. These can have up to 3 receptacles.

Some YouTuber has a 10% coupon code, but I don’t know any more than that. I didn’t hear about the coupon code until after I bought mine.

I have found American Rotary to be very professional, helpful and responsive.









						AMP - Mobile Phase Converter - American Rotary
					

AMP Mobile - The AMP Mobile rotary phase converter is plug-and-play ready for a quick and cost-effective installation. Equipped to run 208-250V equipment in three tiers:     Tier 1: 1 Breaker and 1 Receptacle Tier 2: 2 Breakers and 2 Receptacles Tier 3: 3 Breakers and 3 Receptacles     These...




					www.americanrotary.com


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## Jakedaawg (Oct 31, 2020)

Hmm, I wonder why I ask questions...now I have more research to do.  I thought the only option was the two motor style where one motor spins another...

I appreciate all the replys, thank you folks. 

Now it's off to Google land for me i guess.  Got to figure out the difference between static, vfd, and rotary...


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## matthewsx (Oct 31, 2020)

Simplest option is a static phase converter, just wire it to 220v single phase and hook up your machine. A vfd will require some wiring on your mill but will give you infinitely variable speed control and some other options. A rotary phase converter will serve several different machines and can often be a better option for large older machines with big motors and complex control systems.

You will find many, many threads on here about the different options but if you want the simple answer this is the unit I bought for my lathe and it should work for your application.









						SPC-3
					

Run motors at two-thirds power with the heavy duty SPC-3 Static Phase Converter. This static phase converter offers reliable performance for any industry.




					www.northamericaphaseconverters.com
				





John


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## matthewsx (Oct 31, 2020)

BTW, good to hear you've got one of the Bridgeports to the point where you're ready to power it 

John


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## projectnut (Oct 31, 2020)

I might be an old dog unwilling to learn some new tricks, but in many cases I definitely prefer a static or rotary converter to a VFD.  I looked into the VFD's for both my Bridgeport mill and Sheldon lathe.  In both cases the functions now controlled by the original machine switches would be transferred to the VFD.  That doesn't sound like much of a problem under normal circumstances, but it could come into play in an emergency situation.

I originally learned and regularly perform functions like switching the machine on and  off reaching for the original controls.  Also in the mix are speed changes and directional changes.  An example might be tapping.  I slow the mill to around 90 rpm, engage the part, and allow it to tap to the required depth.  I watch closely with one hand on the forward/reverse switch and reverse directions instantly when the proper depth is reached.  It would take a whole new learning curve to perform this function from a more remotely positioned VFD.  Also in an emergency shut down situation I might find myself through force of habit reaching for the machine push button station rather than the VFD.

These same functions could also be troublesome on my Sheldon lathe.  While the same functions could be programed into the VFD habit and muscle memory would likely kick in should an emergency arise.  The factory push button control station couldn't be more conveniently located.  Even if a VFD was installed in the exact same location it would be a totally different physical function to change speeds, directions, or even power up the machine. 

VFD's definitely have their place.  However there are some situations where the original controls powered by a rotary or static converter are (at least in my mind) preferable.


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## ACHiPo (Oct 31, 2020)

Another vote for North American Phase Converter RPCs—very efficient, quiet, reasonable, and great support.


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## MrWhoopee (Oct 31, 2020)

projectnut said:


> That doesn't sound like much of a problem under normal circumstances, but it could come into play in an emergency situation.
> 
> I originally learned and regularly perform functions like switching the machine on and  off reaching for the original controls.  Also in the mix are speed changes and directional changes.  An example might be tapping.  I slow the mill to around 90 rpm, engage the part, and allow it to tap to the required depth.  I watch closely with one hand on the forward/reverse switch and reverse directions instantly when the proper depth is reached.  It would take a whole new learning curve to perform this function from a more remotely positioned VFD.  Also in an emergency shut down situation I might find myself through force of habit reaching for the machine push button station rather than the VFD.
> 
> These same functions could also be troublesome on my Sheldon lathe.  While the same functions could be programed into the VFD habit and muscle memory would likely kick in should an emergency arise.  The factory push button control station couldn't be more conveniently located.  Even if a VFD was installed in the exact same location it would be a totally different physical function to change speeds, directions, or even power up the machine.



"90 rpm! Ve don't haf all day, vind dat ting up!"

I agree with the point about ingrained habits and muscle memory. If you've been doing it a long time, your reactions in critical situations are almost instinctive. The simple fact that my Kent mill has a 2-speed motor (and switch) causes me no end of problems because all my time in the trade was on single speed machines. I can't count the number of times I've thrown it into high when I wanted reverse.


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## projectnut (Oct 31, 2020)

MrWhoopee said:


> *"90 rpm! Ve don't haf all day, vind dat ting up!"*
> 
> I agree with the point about ingrained habits and muscle memory. If you've been doing it a long time, your reactions in critical situations are almost instinctive. The simple fact that my Kent mill has a 2-speed motor (and switch) causes me no end of problems because all my time in the trade was on single speed machines. I can't count the number of times I've thrown it into high when I wanted reverse.



Old habits die hard.  In my working days most material being machined and tapped was either 316 or 14-4 stainless.  The last thing you wanted to do was break a tap in an inch (or thicker) plate 2 ft. wide and 4ft. long.  Removing a broken tap without ruining the part is one of the most time consuming and aggravating jobs I could think of. 

I was part of a project where one of the machinists broke a 1"-12 tap in a 1 1/2" plate.  Removing the tap was a miserable job.  After multiple tries at disintegrating or otherwise removing the tap finally cut out a plug with a hole saw, turned a new piece on a lathe, pressed it in place, welded it on both sides, machined it flat again (on both sides) and redrilled and retapped the hole.  The whole process took the better part of a day.  It's something I didn't want to repeat, so going slow and easy seemed to be the best way to tell if the tap was having trouble.  If trouble developed the problem could be resolved before it turned into a catastrophe.


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## JimDawson (Oct 31, 2020)

projectnut said:


> I might be an old dog unwilling to learn some new tricks, but in many cases I definitely prefer a static or rotary converter to a VFD.  I looked into the VFD's for both my Bridgeport mill and Sheldon lathe.  In both cases the functions now controlled by the original machine switches would be transferred to the VFD.  That doesn't sound like much of a problem under normal circumstances, but it could come into play in an emergency situation.
> 
> I originally learned and regularly perform functions like switching the machine on and  off reaching for the original controls.  Also in the mix are speed changes and directional changes.  An example might be tapping.  I slow the mill to around 90 rpm, engage the part, and allow it to tap to the required depth.  I watch closely with one hand on the forward/reverse switch and reverse directions instantly when the proper depth is reached.  It would take a whole new learning curve to perform this function from a more remotely positioned VFD.  Also in an emergency shut down situation I might find myself through force of habit reaching for the machine push button station rather than the VFD.
> 
> ...



This is how I solved that problem.  I just replaced the original switch with the VFD




Then later when I removed the mechanical variable speed and went to direct drive, still in the same general area. The VFD is mounted on the back of the machine now.

Speed, For/Rev, Start, Stop


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## MrWhoopee (Oct 31, 2020)

JimDawson said:


> This is how I solved that problem.  I just replaced the original switch with the VFD
> View attachment 342576



That's not smoke on the face of the VFD is it?


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## JimDawson (Oct 31, 2020)

MrWhoopee said:


> That's not smoke on the face of the VFD is it?



Just greasy hand prints.


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## hunter45 (Nov 1, 2020)

I have phase-o-matic static converters and an american rotary rotary converter and a-phase-o-matic rotary converter. I have had good luck with these although I prefer the 2 rotary converters eventually i will ditch the statics and convert completely to rotary


Sent from my iPhone using Tapatalk


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## Jakedaawg (Nov 1, 2020)

Well, gonna pull the trigger on a rotary.  Thanks guys.

Now I am just trying to decide the size.  I want to be able to run the mill and surface grinder.  I eventually will have a lathe I just don't know how big the motor will be for it.  Guessing the standard engine lathes/tool room lathes are 7.5-10 hp?


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## pontiac428 (Nov 1, 2020)

You will want a 10hp unit for a typical 16" lathe.


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## matthewsx (Nov 1, 2020)

Jakedaawg said:


> Well, gonna pull the trigger on a rotary.  Thanks guys.
> 
> Now I am just trying to decide the size.  I want to be able to run the mill and surface grinder.  I eventually will have a lathe I just don't know how big the motor will be for it.  Guessing the standard engine lathes/tool room lathes are 7.5-10 hp?


How big is your shop and how much power is coming in from the utility? Not much point on making it bigger than you can power, and unless you're running a pro shop you'll only be running one machine at a time.

John


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## projectnut (Nov 1, 2020)

I would agree that most 16" lathes are between 7.5 and 10 hp.  However that' a big and heavy machine for almost any hobby situation.  They usually weigh around 5,000 lbs.,  and have maximum speeds in the 1,500 to 1,800 rpm range.

The more common "tool room" lathes are in the 12" to 14" range, weigh around 2,000 lbs., have a maximum speed just north of 2,000 rpm, and use around a 2 to 3 hp motor.

I have a 13" Sheldon MW-56-P.  It has a minimum speed of 48 rpm, a maximum speed of 2,200 rpm, a 56" bed, and uses a 2 hp motor.  I have turned stock up to 12" in diameter and was not at a loss for either power or speed.  I think you'll find similar size lathes (especially 3 phase models) more plentiful and less expensive than the 16" variety.  

As an FYI a friend of mine has a fabrication/repair shop.  He had both a 16" Leblonde and a 13" Leblonde for many years.  He recently let the 16" machine go because the 13" machine is more than adequate for 99+% of the work he has had in the last 10 years.  The 16" machine mainly gathered dust and took up space.  Unless you're doing oil field type work I think the 13" machine would also be more than adequate.


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## Jakedaawg (Nov 1, 2020)

I have plenty of power in the shop.  400 amps of 230v.  I run a marine service business.  I can get 3 phase its just too much on the monthly bill unless my ideas take off.


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## matthewsx (Nov 1, 2020)

Jakedaawg said:


> I have plenty of power in the shop.  400 amps of 230v.  I run a marine service business.  I can get 3 phase its just too much on the monthly bill unless my ideas take off.



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


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## Mikebr5 (Nov 1, 2020)

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.


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## Jakedaawg (Nov 2, 2020)

matthewsx said:


> 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
> 
> ...


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.


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## Jakedaawg (Nov 2, 2020)

Mikebr5 said:


> 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.
> 
> ...


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


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## JimDawson (Nov 2, 2020)

Jakedaawg said:


> 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


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## Papa Charlie (Nov 2, 2020)

Jakedaawg said:


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



I would be very interested in this as well.


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## ACHiPo (Nov 2, 2020)

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




					www.northamericaphaseconverters.com
				











						Rotary Phase Converter 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.


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## Jakedaawg (Nov 3, 2020)

ACHiPo said:


> 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.
> 
> 
> 
> ...


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?


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## ACHiPo (Nov 3, 2020)

Jakedaawg said:


> 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.


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## Jakedaawg (Nov 4, 2020)

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.


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## ACHiPo (Nov 4, 2020)

Jakedaawg said:


> 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.


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## Jakedaawg (Dec 1, 2020)

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.


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## Jakedaawg (Dec 1, 2020)




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## Jakedaawg (Dec 1, 2020)

Well, it showed up too close to beer thirty.  I guess it will be tomorrows' project.


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## pontiac428 (Dec 1, 2020)

You will need at least 3 visits to the hardware store to get everything wired up.  Beer thirty and beer forty five and quarter past beerdom can be taken on the road, because you've got work to do!


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## FlyFishn (Dec 2, 2020)

matthewsx said:


> A vfd will require some wiring on your mill but will give you infinitely variable speed control and some other options



I know I'm late to the party here, but I question the above. Unless AC motors are designed for VFD use I believe running them with a VFD can be detrimental to the life of the motor when run out of spec. 

However, if the VFD control was set up to send the spec power to the motor (not vary the frequency to vary the speed) I can't see how that would be any different than service 3 phase, as the motor would see it. If the object was to vary the RPM of the motor - then my same thought above is there - unless a motor is spec'd for VFD control I believe it will shorten the lifespan of the motor. 

In the case of a large machine like a Bridgeport mill - the motor is something I would want to take a lot of care of and not do anything that would expedite its' demise. 

I know on smaller machines - gear drive lathes for example - VFD conversions (controls AND 3-phase VFD-compatible motor) are popular, but are still expensive conversions. 

Another, possibly off the wall, thought - 

If there is a possible future application in the shop for VFD control to control the speed of a motor on a machine - then the investment of the VFD unit might be a better long-term investment than a RPC, or SPC. Though, if what ever option is chosen is to be married to the mill and never leave then it might make the decision a bit harder. 

Food for thought anyway.


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## JimDawson (Dec 3, 2020)

Jakedaawg said:


> 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.



Please do a favor for me if you have an amp probe.  Would you measure the idle current without your machine turned on, just the input side.  I have been curious about a normal RPC idle current.


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## Jakedaawg (Dec 6, 2020)

When the sparky hooks it up ill ask him to check.  You want to know how many single phase amps it draws from the main panel?  Without a load there would be no amps on the 3 phase side i would think.

@JimDawson


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## FlyFishn (Dec 6, 2020)

@Jakedaawg - with no load on the output (3 phase side) the input (single phase side) current, when "running", would be the "idle current". That is the power it takes unloaded just to power it on, and not pull off the 3-phase output.


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## JimDawson (Dec 6, 2020)

Jakedaawg said:


> When the sparky hooks it up ill ask him to check.  You want to know how many single phase amps it draws from the main panel?  Without a load there would be no amps on the 3 phase side i would think.
> 
> @JimDawson




Yup, just the single phase side from the main panel.  Thank you.


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