[conceptmachinin]

Hello, and thanks for looking.

I am going to be moving my small CNC shop and not going to have an option for 3 phase power. I was wanting to find out what converter would be sufficient in powering it without problems? What service would I need at the shop? I'm not an electrician, just a machinist, so I don't know much about it. Thanks for any help.


The machines power specs are as follows:

Haas VF3

14 kVA;
200-250 VAC @ 50A, 3-phase;
50-60 H

Thanks

Jimmy

[Al_The_Man]

You did not say if more than one machine.
But you need a 220 v 100amp 1 phase minimum, if just the one and to allow for other accessories etc.
If you are looking to expand in the future and you are putting a new service go for a 200amp service.
This should offset the chance of brown-outs & voltage drop due to sudden current demands.
Al.

[conceptmachinin]

Al,

thanks for the help. It is just for the one machine, but I will also need to run a air compressor to supply air for the machine. I was wondering, what size of a Phase Perfect I would need for the mill? I may one day put another mill in also, so that is in the picture too.

Thanks again.

Jimmy

[Al_The_Man]

If you still have the machine connected to 3ph supply, you could take a current reading of the machine with a heavy spindle load to see what the machine typically draws on heavy load and then request a recomendation from phase perfect, of course if you are thinking of expanding then you need an estimated load figure of what you may be looking at in the future.
Also what the compressor draw is.
Al.

[Geof]

......but I will also need to run a air compressor to supply air for the machine.....Jimmy

If you have scanned through various threads you might have seen mention of compressors causing problems to other machines when they kick. It might be worth thinking about a separate unit for the compressor; or get one sized for two machines and when the second machine is installed then move the compressor to its own unit.

Regarding measuring the spindle load as Al suggests taking a reading under cutting conditions may give a value that is below the peak. On Haas machines there is a Parameter (or Setting) called Spindle No Wait.

When this is turned on and the line following the M03/M04 command has a G00 the controller does not wait for the spindle to come to speed it overlaps the spindle acceleration with the rapid move.

This is your peak load when the spindle motor and up to three servos may be drawing 195% of full load. On a VF0 where the machine specs called for a 40mps maximum draw with a biggest single load of 35amps I measured 50amps.

It is possible to turn off Spindle No Wait and it is also possible to set the maximum spindle acceleration lower than 195% but both these work arounds for an inadequate electric supply have an effect on cycle time.

[Al_The_Man]

One thing I forgot to mention, if the Haas has any single phase source wired across two phases e.g. control power, servo or other power supply power, make sure these are across the two main 240v 1 phase feeds, that enter and exit the Phase Perfect. These provide two of the phases that are relatively stable compared to the artificial phase by the PP.
Al.

[Geof]

One thing I forgot to mention, if the Haas has any single phase source wired across two phases e.g. control power, servo or other power supply power, make sure these are across the two main 240v 1 phase feeds, that enter and exit the Phase Perfect. These provide two of the phases that are relatively stable compared to the artificial phase by the PP.
Al.

Yes, coolant pump at least 1hp, may be more.

[awright]

In your situation, I'd consider shedding off the locally generated 3-phase line all equipment that does not REQUIRE 3-phase power for proper operation. This, of course, depends upon the function and power demand of each piece of equipment.

Before people react negatively, I fully realize the advantages of 3-phase power over single-phase in such equipment as compressors, especially as the power exceeds about 2 HP and goes into the region where single-phase motors are hard to find and expensive. However, when you are generating your own 3-phase power locally, peak demand becomes a serious limiting factor.

I'd look first at your coolant pump and air compressor to see if it is practical to convert them to single phase power. The start cycle of an air compressor is an especially large instantaneous current draw that would be beneficially removed from the phase converter. It will draw even larger instantaneous current off the single-phase line, but that is much more easily handled by your direct line power feed than by your phase converter. If your compressor is large enough that it requires a 3-phase motor, do you actually require that much air delivery? Can you go with a smaller compressor or even two smaller ones that will cycle at different instants of time, thereby reducing the peak demand and allowing single-phase power?

Just a thought.

awright

[Al_The_Man]

I'd look first at your coolant pump

I think Geof just indicated it was already 1ph

[awright]

Well, Al_The_Man, I didn't and still, in rereading the thread, don't see where there is mention of the air compressor being either 3-phase or single-phase or where there is any mention of the power of the compressor. I do see where Geof seemed to be recommending a "separate unit" for the air compressor, by which I assumed he was referring to a separate phase converter. Frankly, I don't see the economics of buying a phase converter dedicated to an air compressor alone, as opposed to buying a single-phase motor for the compressor unless it is a relatively high powered compressor (above about 2 HP).

Remember in evaluating the power demand of a compressor that the industry has gotten away with rating modest sized compressor motors that draw current equivalent to an honestly rated 2 or 3 HP motor as a "5 HP compressor-rated" motor. In my opinion, this is pure hokum that has evolved as a competitive gambit in compressor marketing. Look at the actual current draw and "LRA" (Locked Rotor Amps) of the motor you are considering. The LRA is the instantaneous current draw when power is first applied to the motor with a stationary rotor. It only lasts only a fraction of a second until the rotor picks up some speed and begins generating back-EMF to reduce the current toward operating current, but it can play havoc with a phase converter or a weak power source.

I am a strong advocate of VFD phase converters for the home shop and have used a 3 HP converter for several machine tools in my home shop for about 30 years. But I'm not sure that the economics work out for running a moderate size compressor alone, as Goef appears to recommend. As far as I see, we never did hear back from Jimmy on the phase or power of his compressor or coolant pump or other accessories. I admit that I have never used a rotary phase converter and have never required 3-phase power for more than a 2 HP motor.

awright

[Geof]

I mentioned the compressor in one post and the coolant pump in a different one. The pump control is internal to the machine so if you were trying to put it across the main 240 phases you would likely need to trace some wires.

Regarding the compressor surely moving it to a single phase motor would, if it was originally three phase, be more expensive than getting a larger phase convertor or a separate one.

Although thinking further I would expect putting the compressor on a VFD with a soft start capability would be best and probably in the same cost region as a single phase motor for any decent size compressor.

[conceptmachinin]

hey guys, sorry it took me so long to get back. The air compressor is currently running off single phase 220. I hope that helps. I don't know the amp draw but I'm sure I can ask my partner to check it for me. I'm debating selling the mill then buying new....maybe a mill that doesn't require airblow, as the thing darn near runs all the time and is annoying. I found out from the electric supplier that I can get up to 1000 amp service. I talked to him about 3 phase and it seems it would be a bunch of money somewhere around 10,000 just to get it by the land, then I would run the wire from the shop underground to the pole. Hmmm...

Its kinda strange. My shop right now is on a gravel road about 1/2 mile off the same highway that I'm moving too. Its just really funny because There is service off the gravel road, but none 1 mile down the main highway. What a complete drag

[Geof]

...The air compressor is currently running off single phase 220.....

I'm debating selling the mill then buying new....maybe a mill that doesn't require airblow, as the thing darn near runs all the time and is annoying....

I found out from the electric supplier that I can get up to 1000 amp service....
(

Al may chip in with a comment on this but I would expect if the compressor is on the single phase line it is less likely to influence the power going to the machine from the converter. Unless of course the compressor is big enough to need the entire 100 amps at start up.

Your comment about the 'thing darn near runs all the time'; is this the compressor that you are referring to? On a VF3 with the spindle lube air supply correctly set at around 18psi you would need a very small compressor for it to run nearly all the time. I used to run a VF0, two MiniMills and two HL1s on two compressors which were around 2hp each. Have you checked for leaks on the machine?

A 1000amp service at 220volts? Holy something! You will need 1/2" diameter copper bars coming in from the pole transformer

[Al_The_Man]

Al may chip in with a comment on this but I would expect if the compressor is on the single phase line it is less likely to influence the power going to the machine from the converter.

Bang on

A 1000amp service at 220volts? Holy something! You will need 1/2" diameter copper bars coming in from the pole transformer

If you use anywhere near that Kw's it should keep the shop heated
Al.

[conceptmachinin]

No it doesn't run ALL the time, but it runs a lot more than it probably needs. It blowes air for about 30 seconds after the spindle shuts off after a auto cycle, then turns off. If I go to DNC a program right after I run a cycle and the air is on in the machine, it will wait until the program is completely loaded before it shuts off LOL. I think it runs and uses a lot more air than it should. I don't know what horse it is, but I will check.

Are the Phase Perfects a headache? If they are, should I just bite the bullet and put in 3 phase power? I mean, if I need to get another one to run another machine...and so on, should I just do it?

[conceptmachinin]

Bang on



If you use anywhere near that Kw's it should keep the shop heated
Al.

Good, then I won't need heaters!

[Geof]

Good, then I won't need heaters!

Just the opposite!

Did you check the air pressure on the spindle supply?

When the machine is put through the Run In cycle on installation this pressure is set at 30psi. Also if the machine has been unused for several weeks the oil that has accumulated in the lower spindle bearing has to be purged using the Run In at 30 psi.

If the pressure is left at 30 psi the machine will consume a lot of air.

[conceptmachinin]

I had no idea that needed to change. Nobody at haas ever mentioned it. Anyway, I don't even know where the spindle pressure gauge is. The pressure into the machine is set to 80PSI. Its a 2001 model VF3. It has the horizontal tool waiting changer. Is the gauge up under one of the covers? LOL ?? If I don't run it for several weeks, then I would need to turn the PSI up to 30 on the spindle again, and do a run in? I usually do a run in everyday. 2 minutes on 1,000, 2 minutes on 2500, 2 mintues on 5000, 2 minutes on 7500. I usually do everything in high gear, and keep it in M42 mode. Mostly work with plastics and aluminum.



Thanks

Jimmy

[Geof]

.... Is the gauge up under one of the covers? LOL ?? If I don't run it for several weeks, then I would need to turn the PSI up to 30 on the spindle again, and do a run in? I usually do a run in everyday. 2 minutes on 1,000, 2 minutes on 2500, 2 mintues on 5000, 2 minutes on 7500. I usually do everything in high gear, and keep it in M42 mode. Mostly work with plastics and aluminum. Thanks Jimmy

Yes it is at the back hidden up behind one of the covers, or at least that is where it is on the VF0 and VF2. It is a little regulator and gauge, smaller than the main regulator which is down on the back toward the right when you are viewing from the front of the machine (I think).

The program you describe that you run every day is the Warm Up program; the Run In program is longer and it cycles the speed, a minute or so at the high rpm then a few minutes at 500 rpm then back high and so on. It is a two hour program. Some wher in the Haas manual I have seen the information that Warm Up should be done if the machine has not been run for two or three days or if the temperature is below 60 F or something like that. Run In should be done if the machine has not rub for a few weeks.

If you cannot find the Run In program I can post a copy.

[conceptmachinin]

Yeah, that would be cool, that would save me the trouble of writting one I appreciate it!

I will check behind one of the covers tomorrow. Its probably still set on the 30, or whatever it is, when it was installed.

Still debating on 3 phase power. I may just have to drop the money. I hate to do it, but for the long run it may be better.

Jimmy