[SCzEngrgGroup]

The only reasonable option for running a machine over about 2-3HP, that is designed to run on 3-phase, is a rotary phase converter. It's not terribly efficient, and will require a high-current feed into the phase converter, but it will work.

Regards,
Ray L.

[jid2]

^^^ or a proper digital converter like a phase perfect.

[rlockwood]

The only reasonable option for running a machine over about 2-3HP, that is designed to run on 3-phase, is a rotary phase converter. It's not terribly efficient, and will require a high-current feed into the phase converter, but it will work.

Regards,
Ray L.

Why is a digital phase converter not a viable option? I've never looked at the payback from energy savings, so perhaps you'll never make the money back on the initial investment directly.. but in all likely hood your electronics will last longer, and when a drive is a few grand a pop....... Not to mention the noise of a 12hp motor running in the background constantly.

[jid2]

I'm trying to keep my updated space as quiet and easy to work in as possible. Thus digital Phase Perfect for 3 phase power, and a Kaeser screw compressor for air.

[rlockwood]

I'm trying to keep my updated space as quiet and easy to work in as possible. Thus digital Phase Perfect for 3 phase power, and a Kaeser screw compressor for air.

It makes a BIG difference in sanity.. I recently staggered my shift from everyone else here, to get one peaceful day a week without all the noise and interruptions. Silence is golden.

[SCzEngrgGroup]

Silence is golden.

But crazy expensive. A digital phase converter will cost about 5X what a comparable rotary one costs. Same goes for screw compressor vs a conventional one.

If money is no object, by all means go digital. But it will be $$$$. For a whole lot less money, a rotary converter, and a compressor, can be put in a sound-insulated closet or out-building.

Regards,
Ray L.

[rlockwood]

But crazy expensive. A digital phase converter will cost about 5X what a comparable rotary one costs. Same goes for screw compressor vs a conventional one.

If money is no object, by all means go digital. But it will be $$$$. For a whole lot less money, a rotary converter, and a compressor, can be put in a sound-insulated closet or out-building.

Regards,
Ray L.

I'm actually curious how long the payback would be, now.. the cost difference isn't anywhere near as enormous as you make it out to be.

After doing some reading, though, I will say I was incorrect. A digital phase converter is not all that similar to a VFD in function; only the third leg is being generated, while a VFD would actually generate all three legs. As such, I believe a VFD could be used not only to generate 3-phase power, but also to alter voltage and frequency. Certainly wouldn't be a cost effective solution though..

[engnerdan]

Why is my lathe de-rated with single phase 220? The 3 phase hooks right into the VFD just the same as single phase, just 1 more wire.

The only thing derated it the output capacity of the VFD. So if you have a 5HP 3 phase motor, you have to use a 10HP VFD to run it on single phase power. But you are getting a full 5 HP from the motor.

There are 2 basic parts to the VFD
Part 1 - AC to DC converter - Much like the power supply in your computer or wall wart plug in power adapter. It takes the AC power coming in and turns it to DC.

Part in between - There is a bank of capacitors that store the DC from the above section and help provide smooth power to the blow section

Part 2 - DC to AC Inverter - Much the same as the ones you can hook to a car battery and power a computer, or TV when you are camping. In the VFD it is generating the 3 phase power from the DC.


There is a much longer description of why you must derate it. If you want I can explain it but I figured I would start simple.

Cliff Notes - Your motor does not put out any less HP. Your VFD just can not output the nameplate HP when run on single phase.

-Dan

[jid2]

So are you keeping both lathes or swapping out? It wouldnt be a bad idea to get enough 3 phase power to also run a 10hp vmc should you feel like that may be an option down the road.

I selected the single phase option for my new compressor so I have capacity for another machine or something running off the phase perfect down the road.

[Hirudin]

I've been looking at various VMCs (Haas, Hurco, Milltronics, Brother) and every company I've asked so far say they not only tolerate Phase Perfect converters but actually recommend them. They've all said it will not have any affect on the warranty or anything. Word on the 'net is that the digital phase converter is actually likely to deliver better 3-phase than the electric company (something like phases within 1% instead of the electric company's 0 - 5% range - I'm sure this value varies by area). When I talked to American Rotary (the manufacturer) they said their rotary converters are roughly half as much money and are also very efficient and reliable. The 10 HP Phase Perfect is roughly $3000 (plus a couple of possible options and shipping).

[kvom]

My home shop uses a 7.5HP rotary phase converter to run my old Monarch 10EE and my old surface grinder. Rather than buy an integrated unit I purchased the motor and control box (basically some big capacitors for starting the motor) separately. Those who are skilled in electronics can build their own box pretty easily. I use a small VFD to power a Bridgeport and provide speed control.

[BAMCNC.COM]

I'll start off with the rotary, and if I don't like it - I'll sell it on eBay. I need to build a box for my air compressor, so maybe I'll build one that holds both, have a large exhaust fan for cooling. It's already loud in here, I can't see it being louder than my Tormach at 5100rpm.

[BAMCNC.COM]

Oh, and here is the one I got, which is their top of the line model.

(quoted from their site)

Phase Converter ADX10 - 10HP Digital Smart Series Extreme Duty. This 10HP SMART Series Phase Converter is manufactured in the USA by American Rotary and will convert 1 to 3 Phase power and provide 100% power for 208–250v equipment. The ADX series phase converters have current control to provide consistent torque while starting high inertia, extremely hard starting loads, yet are precise enough for CNC applications.

See the difference in our YouTube video!

https://www.youtube.com/watch?v=0gJrYMkNDAE

[engnerdan]

I'll start off with the rotary, and if I don't like it - I'll sell it on eBay. I need to build a box for my air compressor, so maybe I'll build one that holds both, have a large exhaust fan for cooling. It's already loud in here, I can't see it being louder than my Tormach at 5100rpm.

You could add a muffler to the compressor. I have used these at a previous job and they worked well.
Look at the "Inline Muflers for High Frequency Noise"
McMaster-Carr

I built my own just like this but with the correct pipe fittings on each end, but if I were to do it again I would buy one of these and adapt it (air filter on one end and compressor on the other).
Amazon.com : Lighthouse Hydro Duct Muffler Inline Fan Hydroponics Noise Reducer Silencer, 6-Inch : Ducting Components : Patio, Lawn & Garden

Or this
Solberg SLCR-100, Intake/Discharge Tubular Silencer/Muffler for Blowers, 1"FPT, 42 SCFM: Air Compressor Accessories: Amazon.com: Industrial & Scientific

[BAMCNC.COM]

You could add a muffler to the compressor. I have used these at a previous job and they worked well.
Look at the "Inline Muflers for High Frequency Noise"
McMaster-Carr

I built my own just like this but with the correct pipe fittings on each end, but if I were to do it again I would buy one of these and adapt it (air filter on one end and compressor on the other).
Amazon.com : Lighthouse Hydro Duct Muffler Inline Fan Hydroponics Noise Reducer Silencer, 6-Inch : Ducting Components : Patio, Lawn & Garden

Or this
Solberg SLCR-100, Intake/Discharge Tubular Silencer/Muffler for Blowers, 1"FPT, 42 SCFM: Air Compressor Accessories: Amazon.com: Industrial & Scientific

Yep, I actually have one, but the hole is round, I have a square intake on the compressor, just haven't had time to make an adapter.
--
https://www.youtube.com/watch?v=2R5nkNuzb2k

[mountaindew]

I am so low tech.
I moved my device that converts electricity to noise and produces compressed air as a by product to a small mechanical shed.
No noise at all and its even on a different electrical service so no electrical noise also
I plan on adding central vacuum system to shop and place new system in same shed this will remove the other major noise maker in my shop.
And last is nice quiet air cleaner system to improve air quality in my shop and reduce migrant dust into home and machines.
Looking at changing shop lights to led or a higher quality t5 bulb lights. get 4x the light at the same watts and heat.

hard to spend much time in a area and do good work if its not comfortable !
md

[BAMCNC.COM]

Wish I had the luxury of putting stuff outside. I'm already on the edge of the rules in my town right now, since my shop is in my garage. The way my house is laid out, I can't add anything to my garage, and no more yard to add a shed and bury electrical and air lines. Even if I could, our summer is hot and humid and the winter is crazy cold, so nothing would last.

[mklotz70]

Ended up finding a "deal" on eBay on another GT-27 Lathe. Should have a YouTube video of it withen the next 2 weeks. It's the same lathe I have now, but with a Fanuc control, which is why I didn't hesitate. Now back to Rhino Turn for a Post I think. (Only thing with Fanuc is that it's 3phase, where as Fagor is single phase)

Is this actually a problem? All the 3ph stuff I deal with(which is very limited) only uses all 3phases for the motors. All the electronics is run off single legs of 120. A VFD solves the motor issue.

[BAMCNC.COM]

Is this actually a problem? All the 3ph stuff I deal with(which is very limited) only uses all 3phases for the motors. All the electronics is run off single legs of 120. A VFD solves the motor issue.

I agree Mike, same here UNTIL now Fanuc is 3 phase drives, and you can't/shouldn't use a VFD to power the drives

[bhurts]

I don't have a real noise meter so take this with a grain of salt. I downloaded a noise meter app for my android phone and it's supposed to be fairly accurate between 40-80db. I have a American rotary 20 hp phase converter. With the phone 1 inch from the motor I get 65db. 5 feet away I get 55db. It is pretty quiet all things considered. Less then someone talking to you by far. I also tried the meter on a few other things with some surprises. My window unit ac also reads 65db but the volume is that high further away as well as close up. I also have a 3kw Chinese air cooled spindle I checked. At the lowest speed setting (6000 rpm) I get 55db 1 inch from the router. At max speed (18000 rpm) I get 78db 1 inch away. If I walk out of the shop and close the door I get 48 db outside. (cinderblock building with metal roof).If I walk 20 feet from the shop I get 45db and the bugs are louder then the shop. That's with all three things I test inside running at the same time and router at max speed.

Ben