phase inverters ? setting up my shop
- Thread starter 45ACPKING
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This will not work unless you have a 600v input, if you have that you will have 3 phase anyway. You have single phase input 240v so you have to have a 240v vfd. Read what I posted before I have tried all the setups.
VFDs are great if your controls are simple and you are not disconnecting the load with and external control. The vfd must start and stop the motor not your control panel on the machine. If you try to do this the vfd will give you an error, it want's to see the motor all the time. The line side of the vfd can be disconnected no problem. No multi loads. Bonus is the variable speed of the vfd, great on a drill press.
Static phase converters are a rotor phase without an idler motor. DERATE the motor by 1/3 with this setup. You can tune the caps inside the converter to bring the 3rd fake leg to draw the same load as the reset. This is the easiest setup, minutes and you are up and running. You can't run multi loads and under large loads the fake leg can drop out single phasing the motor.
Rotor phase is a little more complicated, you have to start it before you start any of the machines you want to run. It can run multi loads and if you run it thru a step up transformer you can get 600v 3 phase as well. I have this with a remote start. It is noisy if you have it running in the shop. I put it with the air compressor in the back. It will cost a little more to run because you are running an idler motor that produces the 3rd leg.
To answer a few comments.
We could find a single phase compatable motor, but my machinist (50 years in before retirement and bought this machine new) tells me that doing this will put limits on what we can machine.
The machine will be used for hobby use, and some commercial use but I can't get into that.
As for money not being an option... Well, let's be real.
The mill, I have no idea on it's value but it's sitting in our shop and it's stayin there hehehe it and all it's tooling cost me nothing.
It sounds like VFD is the road I'm going down. This a pretty cool learning curve I've been reading and yakkin with my electrician buddies all day LOL
here's a pic of the beast
We could find a single phase compatable motor, but my machinist (50 years in before retirement and bought this machine new) tells me that doing this will put limits on what we can machine.
The machine will be used for hobby use, and some commercial use but I can't get into that.
As for money not being an option... Well, let's be real.
The mill, I have no idea on it's value but it's sitting in our shop and it's stayin there hehehe it and all it's tooling cost me nothing.
It sounds like VFD is the road I'm going down. This a pretty cool learning curve I've been reading and yakkin with my electrician buddies all day LOL
here's a pic of the beast
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You really need to get clear on why a single phase motor will supposedly limit what you can machine. It won't.
Esp not at that HP level.
Essentially, you look at the Frame designation of the motor, find a matching one in Single Phase, hook up the power, and go.
3 phase power is smoother, but if it mattered, you sure wouldn't be looking at THAT machine to do the work. Really. A difference that would be possible to see on a grinder spindle doing fine finish work...maybe. Not going to change what happens on a manual mill. Too many other variables will affect the finish and operations far more. Like how many cups of coffee you had, or whether the end mill was new or used.
I think, as I have said repeatedly, that a VFD is the best choice. I would hope that you understand the pro's and cons of each of the available options, when you choose, though. Based on facts rather than suppositions or beliefs not founded in any facts.
IMO VFD's rock. You can program them to do wonderful and useful things (soft start, variable speed, e-braking, etc) , or you can bury them in the box, and have them only provide what the power Co. won't, straight 3 Phase power at 60 Hz. If the mill has a power reverse switch that operates a relay to do what is called "plug reversing", you are going to have to pay close attention to the VFD as that is one of the things they do not (most) do well. Plug reversing essentially disconnects the motor from power, and reconnects it to the power with two phases reversed. Most VFD's don't deal well with being disconnected from power and reconnected, esp under load.
RTFM. Read the fricken' manual!
That's a pretty solid hunk o' milling machine. If it does not have a power feed on the Knee, that should be your next purchase for it. Cranking the knee up and down gets old fast!
3 phase power feeds? Coolant pump? Gotta factor for them if converting to other than wall source power.
After a power feed on the knee, start shopping for a decent DRO. One of them things, like putting a scope on a rifle (decried as being 'for sissies' essentially, at one time) that makes your life easier and your job faster to a good result.
This look familiar? "My budget for sourcing and installing whatever unit I end up with is of no concern." That would be where the cost is no object idea surfaced, eh? Cost is ALWAYS an object!
Cheers
Trev
Esp not at that HP level.
Essentially, you look at the Frame designation of the motor, find a matching one in Single Phase, hook up the power, and go.
3 phase power is smoother, but if it mattered, you sure wouldn't be looking at THAT machine to do the work. Really. A difference that would be possible to see on a grinder spindle doing fine finish work...maybe. Not going to change what happens on a manual mill. Too many other variables will affect the finish and operations far more. Like how many cups of coffee you had, or whether the end mill was new or used.
I think, as I have said repeatedly, that a VFD is the best choice. I would hope that you understand the pro's and cons of each of the available options, when you choose, though. Based on facts rather than suppositions or beliefs not founded in any facts.
IMO VFD's rock. You can program them to do wonderful and useful things (soft start, variable speed, e-braking, etc) , or you can bury them in the box, and have them only provide what the power Co. won't, straight 3 Phase power at 60 Hz. If the mill has a power reverse switch that operates a relay to do what is called "plug reversing", you are going to have to pay close attention to the VFD as that is one of the things they do not (most) do well. Plug reversing essentially disconnects the motor from power, and reconnects it to the power with two phases reversed. Most VFD's don't deal well with being disconnected from power and reconnected, esp under load.
RTFM. Read the fricken' manual!
That's a pretty solid hunk o' milling machine. If it does not have a power feed on the Knee, that should be your next purchase for it. Cranking the knee up and down gets old fast!
3 phase power feeds? Coolant pump? Gotta factor for them if converting to other than wall source power.
After a power feed on the knee, start shopping for a decent DRO. One of them things, like putting a scope on a rifle (decried as being 'for sissies' essentially, at one time) that makes your life easier and your job faster to a good result.
This look familiar? "My budget for sourcing and installing whatever unit I end up with is of no concern." That would be where the cost is no object idea surfaced, eh? Cost is ALWAYS an object!
Cheers
Trev
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when I said my budget was of no concern...... i'm factoring in the free mill and tooling, tho it cost to get it delivered.
so if i'm into a few grand for getting her going..... not a big deal
acquiring a different shop with the power already available...... my postal code would make that an expensive endeavor indeed
i'm kinda off the beaten path in the bc interior.
thx a tonne for your insight Trev
it was the finish work/quality that I was told could suffer re motoring, so I just have that in my head. i'm no machinist (former steel fabricator/bridge builder)and have a journeyman machinist standing by for when she's all powered up and my at home schooling can begin
so if i'm into a few grand for getting her going..... not a big deal
acquiring a different shop with the power already available...... my postal code would make that an expensive endeavor indeed
i'm kinda off the beaten path in the bc interior.
thx a tonne for your insight Trev
it was the finish work/quality that I was told could suffer re motoring, so I just have that in my head. i'm no machinist (former steel fabricator/bridge builder)and have a journeyman machinist standing by for when she's all powered up and my at home schooling can begin
If you remotor to single phase most of the control relays and overloads have to be rewired therefore you will need special inspection. Also If you add a vfd to replace only the motor feed then again you need special inspection of the machine. If you use the vfd as the power feed only then every time you press the stop button on the machine it will drop out the control relay and disconnect the vfd from it load therefore error message.
Add a rotor phase and you can get a regular inspection. Add a static phase convert with two plug ends and assuming you have a welding plug you can machine today.
Please read more on the subject from what I have read you maybe in for more work then you think.
Add a rotor phase and you can get a regular inspection. Add a static phase convert with two plug ends and assuming you have a welding plug you can machine today.
Please read more on the subject from what I have read you maybe in for more work then you think.
Oops. Wrong model.
http://www.twmi.com/products/controls/drives/JNEV_NEMA4_OP_DEV/brochure_JNEV_06_06.pdf
Not quite. As I mentioned earlier, an equivalent HP in single phase will be somewhat larger physically and may not fit. Otherwise you post has a lot of good info.
single draws more amp and doesn't last as long/heat ups ..and most of time single motors are not as compact
i try to keep the original motor as much as possible... thats what it was designed for ( saves alot of fiddlin for nothin )
vfd is good if your setting up the one machine ...and its lite duty so it should be fine
if your setting the shop up... and you've got machines that start under load ... rotatry is the way, proven by years and years of use
nice mill...bout 1500 to 3500 around here ... becareful transporting it .. i'd bolt er to a sheet o 1/4 plate, so the bastard doesn tip in transit ... if it tips, i wouldn't want it
vfd would allow you to slow down your motor speed (variable speed which is handy ) BUT you'll loose some serious torque .... i've got a 1.5 hp bader grinder with vfd and if i slow down the belt speed, i can easily stall the grinder if i lean into it with some steel ... so if your gonna be slowin down the speed, go to a much larger hp motor
good luck
i try to keep the original motor as much as possible... thats what it was designed for ( saves alot of fiddlin for nothin )
vfd is good if your setting up the one machine ...and its lite duty so it should be fine
if your setting the shop up... and you've got machines that start under load ... rotatry is the way, proven by years and years of use
nice mill...bout 1500 to 3500 around here ... becareful transporting it .. i'd bolt er to a sheet o 1/4 plate, so the bastard doesn tip in transit ... if it tips, i wouldn't want it
vfd would allow you to slow down your motor speed (variable speed which is handy ) BUT you'll loose some serious torque .... i've got a 1.5 hp bader grinder with vfd and if i slow down the belt speed, i can easily stall the grinder if i lean into it with some steel ... so if your gonna be slowin down the speed, go to a much larger hp motor
good luck
What inspection would that be? Electrical? Not had any machines inspected in the 20+ years I have been around them. Different where you are?
The inspectors I have dealt with were concerned up to the point on the wall where the machine gets hooked up. None much cared if I fried the stuff they were not responsible for.
Cheers
Trev
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Aye. I have seen some differences, but as a general state of affairs, they end up longer, and the makers try to keep the single phase replacement motors close to the same size. All part of the puzzle.
Cheers
Trev
Question for OP. What is the voltage input spec. for your motor?
Few of them have multi taps so they can be wired for different voltages so your 220 would work but I have seen many milling machines with strictly 580 volt motors and if that is the case that would impact your decision.
Mike.
Retired industrial electrician.
Few of them have multi taps so they can be wired for different voltages so your 220 would work but I have seen many milling machines with strictly 580 volt motors and if that is the case that would impact your decision.
Mike.
Retired industrial electrician.
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Ministry of labour will go crazy if an employee is hurt by the machine and the original CSA inspection was altered. Licienced electrician can not hook up equipment that is not CSA approved. You may get away with it but if your place burns down or someone gets hurt sh6t will hit the fan. You should call for a special inspection for both the machine and the electrical.
Mike, the mill is in the shop at my buddy's in surry.
We moved it properly with a semi/crane truck. This was all done with exceptional care. I working on my power requirements before I have it trucked 5 hours north. I don't want it sitting "here" if I hit a brick wall with supplying it safe and reliable power.
I'll get a pic sent up of the spec plate and such and let ya know.
Yes then do as you will. If it does burn there probably will be no major investigation. Just wanted the other viewers to be aware. Some people start small and work there way up forgetting some of the short cuts till something happens. Good luck with the project, I would go with the rotor phase if you are think of more machines in the future.
There are a couple VFDs around that will take in and step up or down the voltage, but they are not attractively priced, for sure. Three phase step up/down transformers as well.
I was looking at a small CNC Lathe a short while back, and learned that they (the particular EMCO model I was looking at) were to be avoided unless the transformer was included, as the particular model ran 380v native on the boards, and nothing else would do.
I have a Colchester lathe with a 3HP 575v 3PH motor on it. I have a 220v motor that will bolt right in, the PITA is going to be to swap out the contacts and relays in the system so that the safety stops work. Coolant pump will need a new motor too.
Like as not, I will end up with a second VFD on the coolant pump,when I am done, so that it can run steady while I have variable speed to the main motor.
Wiring that Beaver mill is likely going to be quite a bit more straightforward.
Cheers
Trev
