VFD or not to D....that is the question

[Open Neutral]

An associate has most of a Defiant DMC milling machine. One of several parts he doesn't is the VFD.

It has a Precise SC3062 1.3 KW Spindle motor on it, AC asynchronous 3-phase, 2 pole induction motor. The frequency rang of the motor is 167 - 1000 Hz and a voltage range of 22 - 200VAC. (The motor output shaft spins at 60,000+ RPM.)

Any suggestions on a VFD source? We found mention of PCS410 "frequency converter"...

 

[Besoeker]

An associate has most of a Defiant DMC milling machine. One of several parts he doesn't is the VFD.

It has a Precise SC3062 1.3 KW Spindle motor on it, AC asynchronous 3-phase, 2 pole induction motor. The frequency rang of the motor is 167 - 1000 Hz and a voltage range of 22 - 200VAC. (The motor output shaft spins at 60,000+ RPM.)

Any suggestions on a VFD source? We found mention of PCS410 "frequency converter"...

I think it would have to custom built.

 

[Jraef]

You will no longer find one. New(ish) world wide governmental and military laws now limit the output of VFDs to less than 600Hz, in order to keep them from being used in uranium enrichment. No manufacturer or supplier is allowed to sell or build them as standard. You can try to buy a customized one, but in this country only with specific permission from the Dept. of Defense, the request for which will subject you to a very invasive investigation into every aspect of your life and past, take upwards of a year and cost you a boatload of money.

You are far far better off junking that motor and starting fresh, or figure out a way to make it work for you at severely reduced speeds.

This, by the way, is why many people are dumping older machinery that required this for bargain basement prices, even free.

 

[iwire]

So the though process is that someone would have the knowledge to enrich uranium but custom building a VFD would be beyond them?:huh:

 

[Ingenieur]

So the though process is that someone would have the knowledge to enrich uranium but custom building a VFD would be beyond them?:huh:

to manufacture 10,000 of them as reliably as abb or a-b...yes

 

[Ingenieur]

https://www.amazon.com/Inverter-Engraving-Spindle-Variable-Frequency/dp/B01F7DVS1E

large men with no sense of humor may come a knockin' lol

 

[Phil Corso]

Gentlepeople..

How many of you knew the Centrifuge approach to "Uranium Enrichment" was an Exxon/GE collaboration in the 70's?

Phil Corso

 

[petersonra]

I wonder what prevents someone from making a centrifuge that has a 2:1 gear to the motor. Are gear boxes illegal as well now? Or build a motor with more poles? Or use a DC motor and field weaken it so it runs way fast.

 

[petersonra]

Gentlepeople..

How many of you knew the Centrifuge approach to "Uranium Enrichment" was an Exxon/GE collaboration in the 70's?

Phil Corso

Someone had to invent it.

 

[Jraef]

I wonder what prevents someone from making a centrifuge that has a 2:1 gear to the motor. Are gear boxes illegal as well now? Or build a motor with more poles? Or use a DC motor and field weaken it so it runs way fast.

More poles would make it SLOWER, not faster...

There is more to it than that, gear box increases would not work. The rule actually reads as follows:

a. Multiphase output providing a power of
40 VA or greater;
b. Operating at a frequency of 600 Hz or
more; and
c. Frequency control better (less) than
0.2%.

That last part is what makes gearboxes untenable. To attain 0.2% accuracy you need vector control and direct drive.

Ever hear of the "Stuxnet" virus? That was a virus specifically targeted at VFDs being controlled by Siemens industrial controllers. It made the VFDs run at less than 600Hz, but TOLD the operators that it was running at the speed they wanted (which is not 600Hz, all we know it that it's somewhere ABOVE 600Hz). When the Stuxnet debacle was discovered, the world became aware of the issue so the way to get around it was to attempt to control what VFDs were capable of.

The Amazon one is coming from China, who did in fact sign onto the agreement, but we all know they don't play by the rules anyway. I would not buy any inverters from China sold only via internet only portals with ZERO traceability, certainly not one that is illegal. Most likely Amazon is (as yet) unaware of the violation, but they are potentially in BIG doodoo. They know now...

 

[Open Neutral]

You will no longer find one. New(ish) world wide governmental and military laws now limit the output of VFDs to less than 600Hz, in order to keep them from being used in uranium enrichment...You are far far better off junking that motor and starting fresh, or figure out a way to make it work for you at severely reduced speeds.

Any alternative would be well nigh impossible...

This, by the way, is why many people are dumping older machinery that required this for bargain basement prices, even free.

Shhh!!!! The price was right. It's got a lot of useful features such as a tool changer so that even at 60% of rated RPM it would be useful.

They'd have fun investigating him; he just retired from a USG position where he taught classes to many investigators in various agencies...

BTW: I'd assume it has a gearbox now; otherwise how does 1 Khz get you 60,000 RPM?

And on Stuxnet, all I know about has been in the press, but I wonder if you have it backwards -- the VFD oversped the motor while reporting a normal speed.... I'd think underspeed would not destroy the centrifuges.

 

[Jraef]

Any alternative would be well nigh impossible...



Shhh!!!! The price was right. It's got a lot of useful features such as a tool changer so that even at 60% of rated RPM it would be useful.

They'd have fun investigating him; he just retired from a USG position where he taught classes to many investigators in various agencies...

Well they would not be investigating HIM, he did NOT supply the inverter, right? That's why he didn't... he can't find one either.

 

[Ingenieur]

I wonder what prevents someone from making a centrifuge that has a 2:1 gear to the motor. Are gear boxes illegal as well now? Or build a motor with more poles? Or use a DC motor and field weaken it so it runs way fast.

rpm = (120 x f)/poles
more poles = slower?

gearbox 2.5:1
assuming 2 pole x 400 Hz
motor 24000 = gearbox input
gearbox out = 60000 rpm
that is alot for a mech gearbox for a heavy load like a centrifuge imho

 

[Ingenieur]

Off the shelf in a week
https://www.amazon.com/Inverter-Engraving-Spindle-Variable-Frequency/dp/B01F7DVS1E
many more online
ebay http://m.ebay.com/itm/2-2KW-3HP-VFD-Driver-Inverter-output-220V-Three-Phase-10A-1000Hz-for-CNC-Router-/191554016225

VFD Inverter 1.5kw 2HP 1 phase 220V 1000Hz CNC Engraving Spindle Motor Speed Control Variable Frequency Drive

$200 delivered
220/1 in
0-200/3 out
1000 Hz
1.5 kW

the problem is not a single small one, 1-2 hp, coming into the US
IT's large ones in large qty going to Iran

 

[Jraef]

If that motor is truly designed as 200V 1000Hz, that makes the V/Hz ratio 0.2:1. If you could set up a drive to put out 0.2V/Hz (not sure that's even possible), you could get that motor up to 60% speed if you found a legal VFD that got to 600Hz (actually you will find that most of them stop at 599Hz to be sure because of the wording of the law).

Some VFDs give you the ability to completely customize the voltage and frequency slope like that, most do not, they indirectly determine V/Hz by programming in the motor nameplate data you enter. But because of this law, those type will not allow you to program this motor's nameplate data into them as it shows. You would have to trick it by pretending you have a 120V 600Hz motor. But a glitch I see with that in a drive I found that will go to 600hz, is that you cannot program the motor voltage to be lower than the minimum acceptable voltage of the VFD, which on a 240V class drive is usually 180VAC.

 

[Jraef]

Off the shelf in a week
https://www.amazon.com/Inverter-Engraving-Spindle-Variable-Frequency/dp/B01F7DVS1E
many more online

VFD Inverter 1.5kw 2HP 1 phase 220V 1000Hz CNC Engraving Spindle Motor Speed Control Variable Frequency Drive

$200 delivered
220/1 in
0-200/3 out
1000 Hz
1.5 kW

Already discussed... I doubt Amazon is aware they are breaking the law here, they may not actually allow it to be shipped. The listing, and the company in China that listed it, are brand new.

 

[Ingenieur]

Already discussed... I doubt Amazon is aware they are breaking the law here, they may not actually allow it to be shipped. The listing, and the company in China that listed it, are brand new.

Ebay is on it too lol
where is the law listed?
can't find it under the state dept list

something similar happened in the early 80's
Toshiba sold the ussr (or china?) cc lathes that could be used to make sub props smooth and quiet
no gov docs or contractors that did business could use any of their equip
including copiers lol
had to certify such when submitting a bid

 

[GoldDigger]

BTW: I'd assume it has a gearbox now; otherwise how does 1 Khz get you 60,000 RPM?

And on Stuxnet, all I know about has been in the press, but I wonder if you have it backwards -- the VFD oversped the motor while reporting a normal speed.... I'd think underspeed would not destroy the centrifuges.

1k cycles per second corresponds to 1000 revolutions per second. That works out quite nicely to 60,000 revolutions per minute.

Possibilities would be to overspeed the motor, doing mechanical damage, but only if it could not withstand the maximum output frequency of the drive hardware.
Or it could deliver the wrong V/f ratio and overcurrent the motor, burning it out.
Or is could just vary the speed from nominal, interfering with the enrichment process.

 

[Ingenieur]

One ref
european http://www2.schneider-electric.com/...ation about supplying drives above 599 Hz.doc

 

[Jraef]

Any alternative would be well nigh impossible...



Shhh!!!! The price was right. It's got a lot of useful features such as a tool changer so that even at 60% of rated RPM it would be useful.

They'd have fun investigating him; he just retired from a USG position where he taught classes to many investigators in various agencies...

BTW: I'd assume it has a gearbox now; otherwise how does 1 Khz get you 60,000 RPM?

And on Stuxnet, all I know about has been in the press, but I wonder if you have it backwards -- the VFD oversped the motor while reporting a normal speed.... I'd think underspeed would not destroy the centrifuges.

2 pole motor = 3600RPM (synchronous) at 60Hz. 1000Hz/60hz = 16.67, x 3600RPM = 60,000RPM. No gear box.

I worked for Siemens at the time this all went down. The press got it wrong saying the intent was to destroy the centrifuges. The intent was to not have the enrichment work and have them flail around not knowing why and maybe give up after wasting all that money. That part almost succeeded, but what I heard that they didn't count on was the German engineers working for the Iranians not accepting that the process didn't work (possibly under threat of beheading). They apparently checked the actual speed against what the Siemens software TOLD them the speed was, then found the error and in investigating the cause of the error, found the virus in the software. Ironically the virus was introduced into the system by them. They hacked "free demo" Siemens software that they got in Germany and loaded onto thumb drives, because Iran was prohibited from buying it. Someone (likely the CIA or the Mossad) knew what they were up to and infected that free demo version of the software with Stuxnet.