# Spindle motor ?



## GEORGE D (Apr 2, 2009)

Got a motor with 2 sets of power feeding it, wye-delta. As far as I can see the drive set feeds straight to motor then other feeds through contactor. At times both feeds are going into motor, is that right? Sorry for quick post, working on it now. It's a Cnc and it's running like crap, showing spindle overload with no load and spindle jerking. Help please.


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## JRaef (Mar 23, 2009)

GEORGE D said:


> Got a motor with 2 sets of power feeding it, wye-delta. As far as I can see the drive set feeds straight to motor then other feeds through contactor. At times both feeds are going into motor, is that right? Sorry for quick post, working on it now. It's a Cnc and it's running like crap, showing spindle overload with no load and spindle jerking. Help please.


Your description is confusing, but I understand you may not know what you are looking at yet if you just stuck your head in there. But from your description something sounds drastically wrong here. Sounds almost as though it started out as a fixed speed spindle that used Wye-Delta starting, and someone tried to apply a VFD to it wityhout knowing how to do that. If you have anything with AC power from the line connecting to the same terminals as the output of a drive, you have killed the transistors in the drive.


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## GEORGE D (Apr 2, 2009)

Here's what I'm dealing with, is there any way to bypass the closed loop system to just run motor via drive? Swapped drive, encoder, still have same issue. Like I said, motor doesn't run smooth, it has a jerking pattern. How can I know what's causing this in loop if I can't isolate motor/drive? Also megged motor, it's perfect.


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## Big John (May 23, 2010)

It almost sounds like it's cogging. Are you running at low speed in volts-per-hertz?

-John


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## GEORGE D (Apr 2, 2009)

Big John said:


> It almost sounds like it's cogging. Are you running at low speed in volts-per-hertz?
> 
> -John


Don't quite understand what your saying. Also want to note that spindle wont orient and this motor runs 2 speeds, wye on low and delta on high, 208 volt system, motor has 6 leads. Also note that motor runs bad on both configurations.


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## Big John (May 23, 2010)

I didn't see your second post. I was asking if the drive was set up to run in volts-per-hertz, but I'm guessing not, because you say it's using an encoder for feedback.

Are you trying to take the VFD out of the circuit completely, and just run across the line when the contactor pulls in?


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## GEORGE D (Apr 2, 2009)

No, basically I want to bypass encoder, is that possible?


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## JRaef (Mar 23, 2009)

Ah, so it sounds as thought this is a 2 speed Constant HP motor, that's where the Wye and Delta come in. To use that with a VFD, the contactors that switch the motor leads from Y to Delta will have to be gnat's ass perfect, otherwise the VFD is going to lose track of the motor power information and not be able to track it. Did you change out the contactors?

But I wasn't aware that the old Haas spindle drives had the smarts necessary for running a two speed motor in closed loop vector mode. Was it originally built that way? If so, I guess it was capable. If not, and someone cluged this together after the fact, that may be a problem too.


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## GEORGE D (Apr 2, 2009)

JRaef said:


> Ah, so it sounds as thought this is a 2 speed Constant HP motor, that's where the Wye and Delta come in. To use that with a VFD, the contactors that switch the motor leads from Y to Delta will have to be gnat's ass perfect, otherwise the VFD is going to lose track of the motor power information and not be able to track it. Did you change out the contactors?
> 
> But I wasn't aware that the old Haas spindle drives had the smarts necessary for running a two speed motor in closed loop vector mode. Was it originally built that way? If so, I guess it was capable. If not, and someone cluged this together after the fact, that may be a problem too.


Yes, changed contactors, and yes this was originally setup this way. Could it possibly be gear box? The motor shaft/spindle spin smoothly and freely by hand so I doubt it, but it could explain spindle ol and jerkiness. I'm stumped. Any advice on bypassing encoder? Vfd's are not my specialty.


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## Big John (May 23, 2010)

Jraef is the man when it comes to this stuff, but my $0.02 is that you can't eliminate the encoder without changing the setup of the drive. A vector control setup needs the device feedback to perform properly, because it's constantly comparing real motor speed to commanded motor speed.

-John


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## John Valdes (May 17, 2007)

I would remove the contactors completely, wire the motor for run (high speed) and connect the VFD directly to the motor.
Then using the CNC program I would adjust the speed as necessary.
You will need to be able to program this machine if you make changes to the spindle drive.
I would absolutely continue using the feedback device. This very important on critical equipment and depending on the degree of quality required, you might not be able to dismiss the encoder.
I understand he has a two speed motor. But he should be able to use the high speed alone with direct output from the VFD.


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## JRaef (Mar 23, 2009)

John Valdes said:


> I would remove the contactors completely, wire the motor for run (high speed) and connect the VFD directly to the motor.
> Then using the CNC program I would adjust the speed as necessary.
> You will need to be able to program this machine if you make changes to the spindle drive.
> I would absolutely continue using the feedback device. This very important on critical equipment and depending on the degree of quality required, you might not be able to dismiss the encoder.
> I understand he has a two speed motor. But he should be able to use the high speed alone with direct output from the VFD.


Yes correct, but if it is just 6 leads and Y-Delta configuration, that indicates it is likely a "Constant HP" 2 speed motor, which means in the lower speed winding configuration, the motor is capable of *more* torque. So although he can use the higher speed and turn it down, he will have the *same *torque at the lower speed, not the originally designed higher torque. That's why Machine Tool OEMS do that. 

But it also depends on the nature of the work being performed with the tool. Machine Tools are often designed around the WORST CASE application, but the way it is used may not really need that, in which case I too would recommend getting rid of the contactors etc.

George D, have you tried talking to a Haas dealer about this?

By the way in answer to your specific question: most off-the-shelf Vector drives are now capable of running in open loop vector (sensorless) or closed loop vector, but I don't believe that was the case with those proprietary Haas drives. They were ONLY designed as closed loop vector drives. I believe it will fault out if it does not see a feedback signal from the encoder.


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## GEORGE D (Apr 2, 2009)

Yes, spoke with HAAS but they were of little assistance, they seem to just want to send their own techs out. I'll look into this straight delta connection John mentioned. BTW, how would i know if it could/should be used this way permanently?


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## JRaef (Mar 23, 2009)

GEORGE D said:


> Yes, spoke with HAAS but they were of little assistance, they seem to just want to send their own techs out. I'll look into this straight delta connection John mentioned. BTW, how would i know if it could/should be used this way permanently?


If you do it and it stalls at low speed, you probably shouldn't have done it.


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## GEORGE D (Apr 2, 2009)

Went back today after all this time, to help a friend out ( this was his job from beginning), he rented a vfd to straight wire the motor to. We found that in delta mode it runs like sh!t, and Wye it runs smooth. Any suggestions? I'm stumped. Could the motor be bad on one configuration and not the other?


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## Tsmil (Jul 17, 2011)

Your voltage applied to the windings are 1.73% higher in the delta configuration as compared to the wye configuration. Just maybe you are getting an insulation breakdown. Have you meggered the motor?


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## GEORGE D (Apr 2, 2009)

Tsmil said:


> Your voltage applied to the windings are 1.73% higher in the delta configuration as compared to the wye configuration. Just maybe you are getting an insulation breakdown. Have you meggered the motor?


Yes, meggered motor, but that is an interesting point, although I don't understand how the voltage changes.


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## John (Jan 22, 2007)

It may not be an electrical problem and the problem may be the gearbox. Check the oil level in the gearbox.


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## Tsmil (Jul 17, 2011)

GEORGE D said:


> Yes, meggered motor, but that is an interesting point, although I don't understand how the voltage changes.


Draw it out both ways, delta and wye. The voltage between any two phase in a delta will pass through one winding so phase voltage equals winding voltage. In a wye, the current passes through one winding to the common point and then through another winding. Since these phases are 120 degrees apart, your winding voltage equals your phase voltage divided by 1.73.


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## morens (Nov 19, 2013)

*same problem on VF0*

Hello to all

i have the same problem with a VF-0 machine,but this one doesnt have a delta - wye contactors, it is wired in wye mode trough the vfd to the motor.

like i read in the post of George D , i have the same issue the motor has a jerk behavior when it runs.
in the ocations when it not run, the needle of the load in the operator panel goes to 100% but no response or movement on the spindle or motor. 

this are the things that i try, and the measures that i have made.

Regen resistor 9 ohms (beteewn leads ) and 9 Mohms to Ground.
Motor leads A-b / B-C / A-C 1.1 ohms , any reads to ground. 

i connnect the motor leads directly to the main power and drive by an external contactor and works fine, run smoothly and it feels free turning by hand. 

i think to put some vfd like magnetek , or mitsubishi to this machine , couse the MOCON board has all the conectors, the only thing that i need to mane are the wired but a haas tech told me that if the machine doesnt bring a magnetek o mitsubishi you cant go fron VFD from haas to Magnetek.

i change a magnetek for a powerflex 70 on a vf0 once, that why i think it to do this. 

i try to put some pictores of that later in the post, as i found the way :001_huh:

did you solve the problem?, what was it? the mocon? the vfd?.

i think as long as we could share information about the haas o any machine , the final user feels more friendly with it, and if you want to buy another or recomended to anyone to buy one, that brand will be your first thought. 

thanks for your comments 

best regards


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