Need Help On Converter Choice

[lukebarber]

Ok I bought a leblond 15c lathe a few weeks ago. It has a 7.5 hp motor on it. My question is what is the best way to get 3 phase to this machine? I have 100 amp service in the garage. Static converter? RPC? Change the motor out for a smaller one? I have a used FUJI VFD http://www.clrwtr.com/PDF/FUJI/FUJI-...ini-Drives.pdf that I can also use. I have found a 25 hp RPC for a good price but I'm afraid that it will be too much to start on my 100 amp service. What kind of startup amperage will this draw? I may purchase a compressor, or a bandsaw somewhere down the road so that has me leaning toward a RPC.

Suggestions?

[capitalcrew]

A well built RPC is your best bet. 25hp is pretty big but you should be able to start that on 100 amps. Check the plate on the motor and that should give you an indication of what you'll need.

[jpump5]

Rpc is probably the best for running more than one machine.
Vfd is my choice for one machine.
Static converter(capacitors/voltage relay) would be my last choice.
I work on static converters("phantom phase") at work and don't
have much faith in them. Maybe they would hold up better in
a non-construction site environment.

[lotechman]

I vote for the VFD. You will need a 15 hp VFD in order to convert to 3 phase but you also get in the package, variable speed, slow start, rapid stop with the addition of resistor circuit, overload protection for the motor, low voltage control of the motor allowing small switches and a little potentiometer for speed. You controls are usually 24 volts so you can locate anywhere and not worry about high voltage lines. You also need some sort of electrical box for the VFD and a manual on off to cut main power. I did as 7.5 hp motor on a lathe for under 1K in Canadian dollars complete with a proper box and manual shut off.
You can chuck all the magnetic switches and motor protection that might already be there but likely old as Methuselah. If you sell it the next person can keep all the features if he already has 3 phase power.
I have used https://www.wolfautomation.com/
Best to look at their prices and then email with motor particulars. Old rule of thumb was that you needed double the hp rating in order to convert single to 3 phase. I know that for some makes in the lower hp ratings this does not apply. Another source is https://www.automationdirect.com/adc/Home/Home
A buddy of mine went straight to Ebay and really got a deal. When I say that I mean that he paid a fraction of what I did and I was surprised the unit he bought actually worked... sometimes a gamble.

[Teggy1]

I built a 15 hp rotary phase converter. Unless you have the parts required, some electrical knowledge, and time to build one, I'd highly recommend buying one.

I love my vfd on my mill, but the drawback is rewiring the machine and controls to utilize it. Which is why I did not use one on my lathe, plus the cost.

I think a 15hp VFD may be cost prohibitive, vs buying a comparable rotary, also some of the larger VFDS won't work on single phase, as they monitor each input leg. IF, cost is no object, I would steer you to a phase perfect unit (think vfd that would power your shop similarly to a rotary converter).

Drawback to a rotary is you have to have the space for one ( I wish I didn't have a 15 hp motor sitting on my floor), you get to listen to it while it's running (some find annoying, it doesn't bother me that much, but wish it were outside), the idler is another heat source in the shop, in my case the control box takes up wall space I wish I could make other use of. These may not be a big issue, unless your in a small space.

I'd also avoid a static converter personally.

[greenbuggy]

I built a 15 hp rotary phase converter. Unless you have the parts required, some electrical knowledge, and time to build one, I'd highly recommend buying one.

Cheapest way to do it is look at www.wnysupply.com and just buy the panel, you can pick up a used 3 ph motor up to some pretty descent HP for pennies on the dollar on CL, auctions and eBay if you can find one close.

[7A749]

I've been running my 7 HP Monarch 16 x 30 off a static converter since I bought it in 2004. I got a heavy duty phase o matic.

Personally, I think VFDs are very overrated. Sure, they have their advantages, but for a geared head lathe with a clutch, a static converter will run it just fine in a garage based, one man show deal.

I'm not knocking anyone, or cheapshotting anyone by saying so, but a lot of ppl who insist on a VFD usually have no experience with anything else and they got all their information from Internet forums. Putting a VFD on a geared head machine doesn't really gain you much in the circumstances you intend to use it in. Plus, if you have an issue you can usually count on buying another one to replace it. Yea, they're great for controlling speed and soft starting motors, but they're not cheap and can be quite fickle and prone to damage. Units for larger motors can easily reach into many hundreds of dollars depending on what you buy. For a single machine, unless you had a real good reason to have one on it, I just cannot justify or see the expense for what you gain in such a situation.

The loss of HP thing is another fallacy for the most part in terms of use versus circumstance. Again, some of the Internet experts starting throwing around what they read over on practical machinist, or elsewhere swearing you won't have enough HP to operate your geared head mill or lathe properly without a VFD or rotary converter.

I call BS. I've been running them in my shop on industrial grade equipment since 2000 and have NEVER ONCE stalled out any of my machinery running on one, and I've taken well over 3/16" in a single pass on carbon steel on my lathe with indexable carbide tooling. Again, static converters do have some limitations but for a home shop or one man show working out of your garage, using a basic mill and lathe with motors under ten HP, the limitations are few. I speak from experience, not information I mined off the internet and repeated someplace else down the road.

**A DC drive machine such as a Monarch 10EE is an example of a machine that cannot be run with a static converter** EDIT, read Steve in socal's post for correct explanation on this. Thanks for posting it Steve!


In your situation, a 15 HP rotary would handle your needs fine if you ultimately chose to go that direction. We run one where I work and run several machines at once off it, including an air compressor. You might be able to get away with a pony motor start on the 25 HP rotary. Once the shaft is in motion it doesn't take a whole lot to keep it running. You can buy a complete panel from WNY Converter on eBay as GB said. I've gotten a couple of static converters from them and never had an issue.

Personally, I would slap a HD static converter from WNY on it for the time being and see what happens down the road. It'll be less than $100 (I wanna say I paid around fifty for a HD 3 HP one) delivered and you can purchase something more permenant if your needs change. Once again, we're NOT speaking in exhaustive terms, nor are we talking about using a static converter to power tools or equipment used in a production environment. When those types of demands are present, they must be met in a different way than a single operator working out of his garage on nights and weekends. I don't use my machinery a lot, but I've only burned up one static converter in about 17 years out in my little shop. I'm sold on them as a cheap way to get the job done in my circumstances.

Whatever the case, don't allow Internet forums to complicate what is really an easy situation to solve. I guess at the end of the day, it's all a matter of what you want and how much you have to spend.

IMHO of course

[M J D]

Steve, let us know how you really feel. You know deep down you really lust for a vfd.

[lukebarber]

I talked to AC Tech tech support person. He said their largest single phase drive is 3HP. ESV222N02YXB http://shop.actechdrives.com/AC-Tech...v222n02yxb.htm

I do not know if there are other vendors that offer higher HP single phase drives. I may have to go the RPC route or think about getting a smaller motor.

I'll talk to Wolfautomation to see if they have any suggestion.

Thank you all for your help.

[greenbuggy]

I talked to AC Tech tech support person. He said their largest single phase drive is 3HP. ESV222N02YXB http://shop.actechdrives.com/AC-Tech...v222n02yxb.htm

I do not know if there are other vendors that offer higher HP single phase drives. I may have to go the RPC route or think about getting a smaller motor.

I'll talk to Wolfautomation to see if they have any suggestion.

Thank you all for your help.

Many other manufacturers offer 3 phase drives that will operate on single phase input BUT they must be derated and the derate factor varies from OEM to OEM. I have a 15 HP Parker Eurodrive that will run single at 50% derate powering my 7.5 HP 17" lathe and it works great, but not all drives are capable of single phase operation and AFAIK all 3 phase drives have a derate factor when running on single phase input. Consult the OEM rather than internet "experts" for a given drive.

[Teggy1]

I'll admit not having first hand experience with the static converters.

I've based my opinion on forum discussions, and random written papers.

I've had the belief, as I've read, statics can cause heating problems, to what degree, I have no idea, is it of any practical concern, I don't know that either.
The other possible issue I've read is a slight vibration, this would be of no issue generally, unless using a grinding attachment and surface finish matters. Once again, no experience, and maybe of no practical concern, and as Steve stated, I've drawn my opinion and conclusion from forum discussion. Much in the same way I would generally draw conclusions on many issues, the experienced guys/girls on this forum may give as practical advice.

[forhire]

+1 7A749

On a single machine likely the cheapest and easiest way to get up and running would be a static converter. The tire shop across the alley from me ran a 7.5HP air compressor on a static converter for years. It wouldn't have been my choice but they didn't want to spend the money to drop in three phase even thou it was on the pole. If a compressor can start on a static converter... your lathe will have no issues.

A few years ago I priced out some 7.5HP single phase to three phase VFD drives... unless you happen across a deal used on ebay they will likely be way too expensive. Looking at the spec sheet the Fuji drives top out at 3 HP single phase.

You could change the motor but if your thinking of going RPC in the future than you'd be switching it back anyway. Motor swapping can get expensive sometimes.

One advantage of a VFD is the soft start capability, especially if the load is high. A lathe generally starts un-loaded.

[Steve from SoCal]

OK,

While I am not one to argue with moderators in general and I kinda like Steve from what I have read.

Static phase converters are rather limited in there use. It seems Steve has had good service from his and there is no denying that. A static phase converter uses phase shift to start and run a three phase motor in a condition known as single phasing. This condition occurs when a set of winding fail in a three phase motor once the motor is running. The motor runs at lower power and at higher temperature. A 7.5 HP machine may only need three HP to do most work so the Static converter works, also Steve is not in production where the machine is running for long periods of time. Static phase converters are used to self start rotary phase converters as well.

Because Steve explicitly mentioned it I will address powering a Monarch 10EE. I have a 10EE with a DC drive, there are three different types of DC drives Monarch used on the 10EE. The oldest DC drives are Ward/Leonard drives, a motor/generator using a three phase motor, these have a regular old three phase motor that will run off a static or rotary phase converter of the proper size. I know of a guy who runs a MG 10EE on a 7.5HP static, he has to start the machine at low speed but it works. The next DC drives are vacuum tube electronic drives, while I am lumping these together there are two different versions. They both work in much the same way and these are the drives you hear people roll their eyes at. ALL tube drive Monarch 10EE's are SINGLE PHASE, let me say that again, all tube drive 10EE's were made as single phase machines, the only three phase requirement on these are for coolant pumps. I do have a coolant pump and I did make a small static converter to run it, the coolant pump is a 10th HP motor. The last DC drive Monarch used was a solid state regenerative drive that needs real three phase power or a Phase Perfect type converter to sink regen power back into the grid on braking. This last version was made in small numbers and they are not supported, many of these have been replaced. The machines Monarch sells today have AC motors and inverter drives VFD's.

Static converters work OK when the rated power of your motor is above your demand load. I have machines with 20 HP main motors, even taking massive cuts I have never seen a load meter over about 60%. Does that mean I could use a static converter on these machines? Maybe; one thing to consider with phase converters is, starting load and instantaneous loads. Starting loads on machines like compressors and pumps can be high, lathes with clutches have little starting load so not an issue there, the other load is what a motor will see at a particular time, again many larger machines have excess motor power for the task at hand. So; if your 7.5HP lathe is used in general light to moderate work where you really only need 3-4 HP a static converter would work. It is the least expensive way to go, you may try it and find out it won't work for your needs. You then have the beginnings of a self starting rotary phase converter.

[thegary]

When I first got my 71/2 hp 3 phase lathe I purchased a vfd to run it. The problem is you better always run the lathe with the VFD controls and not the start , reverse buttons on the lathe. One touch of the instant reverse button on the lathe and your VFD will be a paper weight. Don't ask me how I know this. Also as stated if you want to run more than one machine on one VFD forget about it. I would try the static converter first. If it does not work to your expectations then get something better. I installed an electronic converter after I destroyed the VFD and would highly recomend it. A rotary converter will work but are very expensive to run if you are going to run it a lot. The outfit that I purchased my Electronic converter from had rotary converters before and took them out and put in 3 30hp electronic converters. Their electric bill was cut in half. I got mine used from them because they built a new mill that had 480 3 phase power run to it. Now his total motor load is about 650 hp so the electronic converters were not a cost effective option. The brand I have is Phase-Perfect. Mine is for 30 hp but they make 10,20,30,60hp models

[Oldendum]

... and they got all their information from Internet forums...

Hey, I didn't get all my info from the Internet. Some of it I pulled out of my a..

[7A749]

OK,

While I am not one to argue with moderators in general and I kinda like Steve from what I have read.

Static phase converters are rather limited in there use. It seems Steve has had good service from his and there is no denying that. A static phase converter uses phase shift to start and run a three phase motor in a condition known as single phasing. This condition occurs when a set of winding fail in a three phase motor once the motor is running. The motor runs at lower power and at higher temperature. A 7.5 HP machine may only need three HP to do most work so the Static converter works, also Steve is not in production where the machine is running for long periods of time. Static phase converters are used to self start rotary phase converters as well.

Because Steve explicitly mentioned it I will address powering a Monarch 10EE. I have a 10EE with a DC drive, there are three different types of DC drives Monarch used on the 10EE. The oldest DC drives are Ward/Leonard drives, a motor/generator using a three phase motor, these have a regular old three phase motor that will run off a static or rotary phase converter of the proper size. I know of a guy who runs a MG 10EE on a 7.5HP static, he has to start the machine at low speed but it works. The next DC drives are vacuum tube electronic drives, while I am lumping these together there are two different versions. They both work in much the same way and these are the drives you hear people roll their eyes at. ALL tube drive Monarch 10EE's are SINGLE PHASE, let me say that again, all tube drive 10EE's were made as single phase machines, the only three phase requirement on these are for coolant pumps. I do have a coolant pump and I did make a small static converter to run it, the coolant pump is a 10th HP motor. The last DC drive Monarch used was a solid state regenerative drive that needs real three phase power or a Phase Perfect type converter to sink regen power back into the grid on braking. This last version was made in small numbers and they are not supported, many of these have been replaced. The machines Monarch sells today have AC motors and inverter drives VFD's.

Static converters work OK when the rated power of your motor is above your demand load. I have machines with 20 HP main motors, even taking massive cuts I have never seen a load meter over about 60%. Does that mean I could use a static converter on these machines? Maybe; one thing to consider with phase converters is, starting load and instantaneous loads. Starting loads on machines like compressors and pumps can be high, lathes with clutches have little starting load so not an issue there, the other load is what a motor will see at a particular time, again many larger machines have excess motor power for the task at hand. So; if your 7.5HP lathe is used in general light to moderate work where you really only need 3-4 HP a static converter would work. It is the least expensive way to go, you may try it and find out it won't work for your needs. You then have the beginnings of a self starting rotary phase converter.

Great info Steve. Didn't know about the 1 PH thing on the 10EE. My boss has two older ones and learned the hard way a static converter wouldn't run them. At least what he tried. He didn't spend much time messing with it, just went to an RPC. That was when he went to the RPC he has now. He was the source of the info I posted regarding it. He said he had an awful time trying to get it to run on a static converter. The later model Monarch he has he's planning on converting to a straight VFD drive when we move to the bigger shop.

I appreciate your input on it and I know you are bone fide no doubt. I added an addendum to my comments so if anyone sees them they can get the correct info from your post. Never have a problem being wrong about something, especially when you learn something you didn't know!

I guess my general reasoning is, when I see a bunch of ppl tell a guy with a frigging cold saw (in his garage) to buy a VFD to run it, and some of those ppl don't own machine tools, never have owned them and know almost nothing about them, it rubs me a little wrong lol. Even more so when I know some of those ppl didn't have a clue about much of anything when they joined this site, but now speak as tho they're an authority on the subject lol.

I have nothing against one and plan on buying one for my Burr King belt grinder when I get to rebuilding it.

Besides that, I just don't see the need for one to run my machine tools when what I've been using for close to 17 years has worked so well.

IMHO of course

[7A749]

Steve, let us know how you really feel. You know deep down you really lust for a vfd.

Yeah, you have a pretty good idea how we feel around here

[M J D]

Yeah, you have a pretty good idea how we feel around here

Do they make vfd in extreme green?

[7A749]

God if they did I would buy it without question...

It would go with my green Milwaukee cordless tools

[7A749]

Hey, I didn't get all my info from the Internet. Some of it I pulled out of my a..

I'm quite proficient at that too

[7A749]

I'll admit not having first hand experience with the static converters.

I've based my opinion on forum discussions, and random written papers.

I've had the belief, as I've read, statics can cause heating problems, to what degree, I have no idea, is it of any practical concern, I don't know that either.
The other possible issue I've read is a slight vibration, this would be of no issue generally, unless using a grinding attachment and surface finish matters. Once again, no experience, and maybe of no practical concern, and as Steve stated, I've drawn my opinion and conclusion from forum discussion. Much in the same way I would generally draw conclusions on many issues, the experienced guys/girls on this forum may give as practical advice.

You did it right man. If I were doing it over again, I would have put a rotary in from the beginning and called it good. My comments were not to single anyone out (most certainly not you bro) or point fingers, I just know from a single light user standpoint that the static converters do the job to a limited degree and do it well for what they are. Like I said above, when I see ppl who I know don't know jack about machinery telling a guy with a geared head cold saw to spend several hundred dollars on a VFD to power it it grinds me good.

I plan on putting one on a belt grinder I'm going to rehab in the future.

Oh, I will get your stuff out soon. I had furnace problems this weekend followed by an alternator problem in my car the other day that left me dead on the freeway lol. Just wanted to make sure you knew I didn't forget about you

[7A749]

When I first got my 71/2 hp 3 phase lathe I purchased a vfd to run it. The problem is you better always run the lathe with the VFD controls and not the start , reverse buttons on the lathe. One touch of the instant reverse button on the lathe and your VFD will be a paper weight. Don't ask me how I know this. Also as stated if you want to run more than one machine on one VFD forget about it. I would try the static converter first. If it does not work to your expectations then get something better. I installed an electronic converter after I destroyed the VFD and would highly recomend it. A rotary converter will work but are very expensive to run if you are going to run it a lot. The outfit that I purchased my Electronic converter from had rotary converters before and took them out and put in 3 30hp electronic converters. Their electric bill was cut in half. I got mine used from them because they built a new mill that had 480 3 phase power run to it. Now his total motor load is about 650 hp so the electronic converters were not a cost effective option. The brand I have is Phase-Perfect. Mine is for 30 hp but they make 10,20,30,60hp models

This right here is a big reason I feel the way I do about VFDs for general machinery operation. One wrong move and it's a done deal. There's very little room for error and from my experience wrenching on inverter welders for the better part of ten years, such electronic systems are extremely sensitive to power surges, spikes and other stuff that just plain happens during the course of shop work. Mistakes and even legitimate problems are costly and also easy to make if you aren't paying very close attention.

The static converter is pretty idiot proof (which is a great thing for me lol). I don't have to sweat a surge or accident taking out a $300 VFD when I'm in the middle of a job and need to get it done.

I've also talked to my boss at length about your friends experience after he moved into the shop with 480 at the pole. I've encouraged him to just put a 20 HP rotary in the bigger shop once he gets the deal closed. I know it's going to save him money, even tho it doesn't seem like it from the outset. Most of his demand is low power machinery, on an intermittent basis. I'm glad a few ppl here have shared their experiences about this stuff.

My next shop will have a rotary panel and I'll just set it up the way from the start. I don't need a lot of power, so I can get by with something simple. Prolly go with a factory built panel and power an idler with it.

IMHO of course

[bead-boy]

OK, I'm trying to ingest as much of this as possible but now my head hurts. I have an opportunity to use a neighbors Clausing drill press that is 3 phase (I am trying to talk him out of buying a 1ph motor for it). I have also seen 3 phase machines at auction that I could pick up cheap. Like a pedestal grinder. A mill is on my list some year in the future. Will a single static converter run all the above, if I unplug one and plug in the other?

[Teggy1]

You did it right man. If I were doing it over again, I would have put a rotary in from the beginning and called it good. My comments were not to single anyone out (most certainly not you bro) or point fingers, I just know from a single light user standpoint that the static converters do the job to a limited degree and do it well for what they are. Like I said above, when I see ppl who I know don't know jack about machinery telling a guy with a geared head cold saw to spend several hundred dollars on a VFD to power it it grinds me good.

I plan on putting one on a belt grinder I'm going to rehab in the future.

Oh, I will get your stuff out soon. I had furnace problems this weekend followed by an alternator problem in my car the other day that left me dead on the freeway lol. Just wanted to make sure you knew I didn't forget about you

Understand your point, and it is a good point.

My intent was to clarify to the OP, and others that I don't have first hand experience with static converters. And as you stated draw my conclusion from forum discussions, mainly. Didn't really take it as being singled out, rather felt the need to reiterate your point.

Actually glad to hear another perspective from a practical standpoint.

VFDs are great in certain applications, but as stated, have their nuances. I definitely wouldn't consider them the end all solution.
I usually end up going overboard on projects, while my vfd seemed like a lower cost easier alternative to a rotary when I first fired up my mill, I ended up spending at least 2x the initial vfd cost on an enclosure, VFD rated cables, connectors, a line reactor (which probably wasn't needed), a thermostat, cooling fan and vent to ensure enclosure temp was never an issue, and a large braking resistor (which I ended up not even using).

Same with my rotary converter. I way over built the electrical stuff, and I'm sure it's sized large enough to power at least a 20-25 hp idler. I ended up spending nearly what a purchased rotary would have cost (smaller 10 hp unit), but many times, for myself it isn't just about cost. It is a learning project for me, and I find it enjoyable to see everything work as I hoped it would.

Hope your luck turns around, seems like every time I have good intent to get something done, everything blows up for me too! How does that saying go? If you want to make God laugh, tell him your plans. Or something to that effect. I've found that to be true in most situations! I usually can't tell who I'm working with, him or Murphy. Maybe they take turns, sometimes I'm sure they're teamed up!

[7A749]

OK, I'm trying to ingest as much of this as possible but now my head hurts. I have an opportunity to use a neighbors Clausing drill press that is 3 phase (I am trying to talk him out of buying a 1ph motor for it). I have also seen 3 phase machines at auction that I could pick up cheap. Like a pedestal grinder. A mill is on my list some year in the future. Will a single static converter run all the above, if I unplug one and plug in the other?

Im sure you could set something up to run multiple machines, but I've never done it. You connect them to the load side of the starter running the motor. On my lathe, I connected it with a 50 amp single phase circuit breaker to act as the power switch. The magnetic starter was shot and I didn't feel like screwing around with putting another one in it. I ended up using a drum switch to reverse the motor when needed. For as cheap as they are, I would just put one on the machines needing to be ran and be done with it.

It's really quite simple. The instructions that come with them are pretty straightforward and installation is a cord with three wires going from the converter to the load side of the starter..

As I've stated before, a static converter is not the answer to every machine tool powering situation. They do however, provide a very simple, economic and effective solution to powering three phase equipment on home shop single phase power.

That in itself makes it a Jeet Kune Do worthy technique as far as that goes

WNY converter has great prices on USA made gear. For our type of needs, their value is hard to beat.

IMHO of course