# 6 Lead Motor



## Big John (May 23, 2010)

Silly question, but are you supplying it with the same voltage in both configurations?

-John


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## JRaef (Mar 23, 2009)

Big John said:


> Silly question, but are you supplying it with the same voltage in both configurations?
> 
> -John


Lol, "minor detail"... :whistling2:


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## John Valdes (May 17, 2007)

If you are doing the switch to delta with a contactor arrangement, it is wired wrong.
This is very common.
Now, if you are connecting this motor directly to the source and it runs fine in wye and not fine in delta, the sun is going to go out today.


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## retiredsparktech (Mar 8, 2011)

John Valdes said:


> If you are doing the switch to delta with a contactor arrangement, it is wired wrong.
> This is very common.
> Now, if you are connecting this motor directly to the source and it runs fine in wye and not fine in delta, the sun is going to go out today.


Are you're sure the leads are marked properly? You should get equal resistance between leads 1&4, 2&5 and 3&6 with all the leads disconnected and no continuity to the other pairs.


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## GEORGE D (Apr 2, 2009)

John Valdes said:


> If you are doing the switch to delta with a contactor arrangement, it is wired wrong.
> This is very common.
> Now, if you are connecting this motor directly to the source and it runs fine in wye and not fine in delta, the sun is going to go out today.


Yes, this is how I'm doing it. Never changed the wiring, machine used to work. I thought of same thing, i guess there's always a probability someone else f$&ked with it and is playing the silent game.


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## alpha3236 (May 30, 2010)

You didn't indicate if the leads were marked. I run into this a lot in the field. The motor is probably wired in a wye/wye configuration for part winding start with 4,5,6 and 10,11,12 tied together internally. If your starter is set up for across the line, 1&7, 2&8, 3&9 go to the starter. Good luck.


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## JRaef (Mar 23, 2009)

Now trhat we know more, it sounds to me as though you have at least one bad contact in your 2M contactor (assuming standard NEMA configuration, open transition Wye-Delta starter.) 










In Start (Wye), 1M and S contactors are closed, no problem. When it transistions to Run (Delta), S opens, then 2M closes. If the issue only happens when 2M closes, then that points to it being a burned contact in 2M. Very common on Wye Delta starters by the way, and it may indicate that it is set to transition too soon. If it is, the motor is at less than 80% speed, so the current through 2M is higher than the contactor is rated for. It's affecting 1M as well, but since 1M is already closed, there isn't as much damage. 2M is CLOSING on too high of a current.

If you have an IEC type starter, 2M is typically called KM2


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## GEORGE D (Apr 2, 2009)

Swapped CONTACTORS and still same problem.


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## John Valdes (May 17, 2007)

If the motor runs in wye and delta connected directly and independently from the source it is not the motor. It is the wiring or the either of the contactors. 
*This is very common. Someone removes a six lead motor from a wye/delta start application and cannot get the motor to work/run.*
99% of the time it is error on the installer. The guy hooking the motor back up.
So have you ran this motor separate from the contactors? Directly with a cord or other means?
Try this and make certain. Then you can be sure what you have.
Jraef has the wye/delta start configuration posted. So verify the wires are connected as shown.


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## John Valdes (May 17, 2007)

GEORGE D said:


> Swapped CONTACTORS and still same problem.


Which two? If you moved them, you might still have a bad one in the delta circuit.
The contactor with three leads shunted is not in the circuit in delta.


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## GEORGE D (Apr 2, 2009)

If the motor in delta turns but very very jerky, is that a characteristic of bad connection or would it not spin at all?


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## JRaef (Mar 23, 2009)

GEORGE D said:


> If the motor in delta turns but very very jerky, is that a characteristic of bad connection or would it not spin at all?


Because it is ALREADY spinning by then, it will KEEP spinning, but you would have the equivalent of a single phase condition.

This diagram shows a better concept of what's going on in the motor windings. So if you have a bad contact or even a bad connection in the wires going from 2M to the motor, then you have an incomplete circuit to the windings once S opens and 2M closes. Single phase operation of a 3 phase motor sounds rough under load.


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## GEORGE D (Apr 2, 2009)

I'm gonna explain a little better:

Because this is a vector drive and it cannot be used otherwise, we rented an equivalent drive to be able to test motor/gearbox directly. We unhooked wires from oem drive , tied to ours, and manually pushed each contractor in to test individually (not changing from one to other while motor still spinning, each time was from dead start). We tried all different speeds in both configurations and only wye would work properly. As I stated before, the delta ran awful every time. It would spin from dead start but very jerky, in all speeds. We initially thought the gear box was at fault , mainly because of the sound it was making, but I don't think that would make much sense. We also swapped contactors to make sure that wasn't it. Hopefully this explains the scenario a little better.





JRaef said:


> Because it is ALREADY spinning by then, it will KEEP
> 
> spinning, but you would have the equivalent of a single phase condition.
> 
> This diagram shows a better concept of what's going on in the motor windings. So if you have a bad contact or even a bad connection in the wires going from 2M to the motor, then you have an incomplete circuit to the windings once S opens and 2M closes. Single phase operation of a 3 phase motor sounds rough under load.


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## JRaef (Mar 23, 2009)

GEORGE D said:


> I'm gonna explain a little better:
> 
> Because this is a vector drive and it cannot be used otherwise, we rented an equivalent drive to be able to test motor/gearbox directly. We unhooked wires from oem drive , tied to ours, and manually pushed each contractor in to test individually (not changing from one to other while motor still spinning, each time was from dead start). We tried all different speeds in both configurations and only wye would work properly. As I stated before, the delta ran awful every time. It would spin from dead start but very jerky, in all speeds. We initially thought the gear box was at fault , mainly because of the sound it was making, but I don't think that would make much sense. We also swapped contactors to make sure that wasn't it. Hopefully this explains the scenario a little better.


Anything else you are not telling us, or do we have to keep guessing?

You are closing contactors on the output side of a VFD, not knowing how the motor is connected? Have you blown the transistors on the VFD yet? 

You are closing ONLY the 2M contactor, withOUT closing the 1M contactor? And it runs at ALL?

What is the status of the S contactor in all these tests?

And why would you have a Wye Delta starter on the output of a Vector drive? Makes no sense whatsoever!

Are you even sure this is a Wye Delta motor? 6 leads could be Part Winding or 2 speed. Do you have a nameplate for it?

Sorry, I'm willing to help (one more time anyway) but there are several things wrong on several levels here and you are parceling your statements a little too much.


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## GEORGE D (Apr 2, 2009)

JRaef said:


> Anything else you are not telling us, or do we have to keep guessing?
> 
> You are closing contactors on the output side of a VFD, not knowing how the motor is connected? Have you blown the transistors on the VFD yet?
> 
> ...


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## DriveGuru (Jul 29, 2012)

GEORGE D said:


> Easy big guy, no ones trying to hold out on info, I know I sound confusing its just that this is part of an older thread I started that I'm just now getting back to. I tried reviving it on its original thread but no one would engage. And as for closing contacts on a drives output, I know at least not to do that, one would hold it in prior to starting drive. After looking over your diagram above, I believe this set up has no M1 contact, just M2 and S2. Does that make sense? This is a HAAS machine if that matters any. So basically we would hold in M2 CONTACTOR, start drive, then repeat for S2, and motor only ran smooth in S2 mode. All control wiring for contactors were disabled. Hope thus helps and sorry for sounding so confusing.


Hi George , you'd be best off to lose the contactors and wire delta configuration directly to the drive. Once on the inverter be sure to tune it, jerky operation you may want to check the encoder unless it's a sensor less drive. Also look close at current limit/ torque limits, a wye-delta motor will have higher peak currents in delta configuration than it will in wye. Hope this helps.


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## DriveGuru (Jul 29, 2012)

Oops forgot to mention, make sure the motor is unloaded, bare shaft is best. I'm assuming this is a spindle?


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