# delta source, wye motor



## McClary’s Electrical

te12co2w said:


> Delta source, wye motor.


 transformer


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## jwjrw

Agree :thumbsup:


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## alpha3236

Why the XFRMR? I wire Wye motor windings to an open delta/high leg system all the time. Motors don't care as long as the phase to phase voltage is within specs.


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## te12co2w

*alpha*

That's one of the questions I had. I almost thought it might be something like that. This motor is rated 200-230v 3-phase. I think it is a wye. Power source is a phase converter that has no load readings of 237v line to line & 252v line to line delta. The converter tech said that when a load is applied the voltage would drop and stabilize. I don't know what it would drop to though. Would 240v be too much for a 200-230v hermetic compressor motor?
This one came through


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## micromind

A motor doesn't care what connection the source is, it only cares about phase to phase voltage. 

A wye connected motor will operate just as good on a delta system as it will on a wye. A delta connected motor will operate on a delta system or a wye one. 

Rob


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## Jlarson

micromind said:


> A motor doesn't care what connection the source is, it only cares about phase to phase voltage.
> 
> A wye connected motor will operate just as good on a delta system as it will on a wye. A delta connected motor will operate on a delta system or a wye one.


I hope so cause I have been hooking wye motors to delta systems and vise versa all along without involving a transformer.


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## jwjrw

alpha3236 said:


> Why the XFRMR? I wire Wye motor windings to an open delta/high leg system all the time. Motors don't care as long as the phase to phase voltage is within specs.




I assumed his voltage would not be in range. At the time he had only posted delta source wye motor and no other information.


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## micromind

Jlarson said:


> I hope so cause I have been hooking wye motors to delta systems and vise versa all along without involving a transformer.


Me too. Hundreds of them; maybe even a few thousand. lol.


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## micromind

te12co2w said:


> That's one of the questions I had. I almost thought it might be something like that. This motor is rated 200-230v 3-phase. I think it is a wye. Power source is a phase converter that has no load readings of 237v line to line & 252v line to line delta. The converter tech said that when a load is applied the voltage would drop and stabilize. I don't know what it would drop to though. Would 240v be too much for a 200-230v hermetic compressor motor?
> This one came through


240 is fine for a 208-230 volt motor. The upper limit on such a motor would be 253. 


I'd be a bit hesitant to connect a refrigeration compressor or a submersible well pump motor to a phase converter. These motors tend to be 'high-strung' and less tolerant to voltage imbalance than most. 

Given the choice, I'd use a VFD rather than a phase converter. Even a rotary one.

Rob


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## jwjrw

micromind said:


> I'd be a bit hesitant to connect a refrigeration compressor or a submersible well pump motor to a phase converter. These motors tend to be 'high-strung' and less tolerant to voltage imbalance than most. Rob




That is why I said I assumed the voltage would not be in range.


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## Jlarson

micromind said:


> I'd be a bit hesitant to connect a refrigeration compressor or a submersible well pump motor to a phase converter. These motors tend to be 'high-strung' and less tolerant to voltage imbalance than most.


I'm not. 

I prefer to use VFDs too but I have dealt with some situations where a converter was a much better fit. I usually up-size the converter, and on wells I put a soft start on it, and on HVAC stuff install a hard start kit.


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## McClary’s Electrical

alpha3236 said:


> Why the XFRMR? I wire Wye motor windings to an open delta/high leg system all the time. Motors don't care as long as the phase to phase voltage is within specs.


I didn't say it was the only way to do it, but it is one way.



micromind said:


> A motor doesn't care what connection the source is, it only cares about phase to phase voltage.
> 
> A wye connected motor will operate just as good on a delta system as it will on a wye. A delta connected motor will operate on a delta system or a wye one.
> 
> Rob


I've seen Wye/Delta motors hooked to a delta source that will not produce torque from being wired for Wye. If there's NO DIFFERENCE, as you say, why would ther be such an animal as a Wye/delta starter? And how would it work?



Jlarson said:


> I hope so cause I have been hooking wye motors to delta systems and vise versa all along without involving a transformer.


 
We must be talking about 2 different animals. The motor referneced above was 100 hp Wye/ Delta motor. Wired for Wye, but hooked to a delta source, and would not run the machine. I was the third electrician who had troubleshot the brand new machine. I rewired the motor for delta, and the machine then had enough strength to lift logs. (which is what it's designed to do, but would not do at start up)


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## RePhase277

A wye/delta starter just changes the motor connection, not the source connection. A wye connected motor doesn't have a neutral connected to its center point, so how could the motor possibly know how the source was configured? 

If you had a 240 V delta transformer supplying a three phase load, then switched to a 240 V wye connected transformer, the load would never know as long as the voltage is the same.


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## McClary’s Electrical

InPhase277 said:


> A wye/delta starter just changes the motor connection, not the source connection. A wye connected motor doesn't have a neutral connected to its center point, so how could the motor possibly know how the source was configured?
> 
> If you had a 240 V delta transformer supplying a three phase load, then switched to a 240 V wye connected transformer, the load would never know as long as the voltage is the same.


 
BS!!!! You are crazy. If you supply WYE voltage to the same motor wound and tapped for delta , you will experience 78% overvoltage, and the motor will OVER HEAT.


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## RePhase277

mcclary's electrical said:


> BS!!!! You are crazy. If you supply WYE voltage to the same motor wound and tapped for delta , you will experience 78% overvoltage, and the motor will OVER HEAT.


If you have a 240 V delta, and a 240 V wye, how is 240 V 78% larger than 240 V?


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## McClary’s Electrical

Delta


Delta


GOOD


Wye


Wye


GOOD


Delta


Wye


BAD


Wye


Delta


BAD



Results of incorrect electrical configuration:

Due to the above mentioned wrong connections, both loads and sources suffer from poor power quality. Typical examples of problems due to incorrect electrical configurations at the load end are: bearing current, excessive armature current in the motor winding, motor case carrying current, more stray losses and imbalances in the load. Problems at the source end are: transformer heating, leakage inductance, buzzing noise, stray losses and decrease of life expectancy. Above all, ground loops created due to the wrong electrical configuration affect the rest of the electrical system by reverse current causing widespread malfunctions. 

Sample Case Study: The below graphs are of a distribution system where delta motor is fed by a wye secondary of a transformer.












The above graph shows electromagnetic disturbance from 3 kHz to 100 kHz. The electromagnetic disturbance is pretty high at -20dB. 











The above graph shows the 3 phase current waveforms. The current is not evenly distributed among the three phases. Neutral current is zero since the motor is delta and there is no neutral in delta. For good power quality, crest factor should be 1.4. In the above case it is little high, reaching 2.4. This means that there is heavy reverse current affecting the peak voltage and dominating the RMS voltage. This is all due to the return path of current running on phases for a delta motor from a wye transformer.


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## micromind

A wye/delta starter is used with a motor that would be connected delta if it were started across the lines. The motor must have 6 leads if it is single voltage, and 12 leads if it is dual voltage. There are always 6 wires from the motor to the starter. There are 3 contactors in the starter, two of which are interlocked (both electrically and mechanically) so they can never both be closed at the same time. 

When the starter is first energized, it connects the motor wye. This results in about 1/3 of locked rotor current, and about 1/3 of the locked rotor torque. After a set amount of time (this can be a relatively long time, even up to a full minute), it switches the motor connection to delta. 

The incoming power connection doesn't matter; it can be a wye or a delta. The starter and motor only see phase to phase voltage, the neutral is not involved.

If we have a single voltage motor that has 6 leads (we'll use 460 volts) the delta (run) connection would be L1=T1&T6, L2=T2&T4, and L3=T3&T5. This is the delta connection; it is used for starting across the lines and for running with a wye-delta starter. It has to have 460 (480) volts phase to phase in order to produce its rated HP.

If this motor is connected wye (L1=T1, L2=T2, L3=T3, 4,5,6 spliced) it would need 796 volts in order to produce its rated HP. Since it is supplied with 480, it will produce far less than its rated HP. 

In Mcclarys example, if the 100HP motor was delta wound and it was connected wye, it would produce about 30HP. I don't think a 30HP motor would turn a 100HP machine very well. lol. 

When the motor was connected delta, it was able to produce 100HP, and would then run its load as intended. 

The above example has nothing to do with the connection of the incoming power, it is a connection of the motor itself. 

Hope this makes sense, if it doesn't please ask for better clarification.

Rob


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## McClary’s Electrical

*Problems with using incorrect electrical configurations*: 

The electrical configuration of the source and the load should be same under any circumstances. That is, a Delta load should be connected to only a delta source and a Wye load should only be connected to a wye source. They should not be switched irrespective of the occasion. 

*Delta system (Load) connected to Wye system (Source)*:

Assume a Delta load is connected to Wye source in an electrical distribution system.












According to the nature of a delta system, it will allow one of the opposite conductors for the return path of current. The fundamentals of an electric circuit say that a circuit has to be completed (circled) in order to deliver power from the source to the load. When the return path of the delta system is on one of the phases, it is directed to the phase of the wye source. Clearly, the phases are not evenly distributed at the source since neutral has to be the return path of current at the wye source. This return path of current will create a floating ground in the electrical system. A floating ground is a common connection in a circuit that provides a return path for current but is not connected to an earth ground. In the same fashion, disturbances at the source (wye) can not pass thorough neutral as the circuit is not completed with it. Since neutral is bonded to the ground at the main panel, resultant unwanted current at this point will go to the ground. The consequence is a ground loop. If the ground is not in a loop and is bonded only to the ground rod, then the return current will be on one of the phases of source and the transformer. This will lead to imbalance in the phase distribution and harm the load. 

*Wye system (Load) connected to Delta system (Source)*:
Assume wye load is connected to delta source in an electrical distribution system: 












At the load end, the return current takes the neutral path. But the neutral of the wye load has no connection to the delta source. The neutral at the load is connected to the ground. Now the return path of current is through the ground wire at the load. It creates ground loops in the electrical system, and this causes the ground wire to carry current in the electrical system. This phenomenon breaks all laws of fundamental electricity. Ground is designed for safety and it should not carry any current.


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## micromind

mcclary's electrical said:


> *Problems with using incorrect electrical configurations*:
> 
> The electrical configuration of the source and the load should be same under any circumstances. That is, a Delta load should be connected to only a delta source and a Wye load should only be connected to a wye source. They should not be switched irrespective of the occasion.
> 
> *Delta system (Load) connected to Wye system (Source)*:
> 
> Assume a Delta load is connected to Wye source in an electrical distribution system.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> According to the nature of a delta system, it will allow one of the opposite conductors for the return path of current. The fundamentals of an electric circuit say that a circuit has to be completed (circled) in order to deliver power from the source to the load. When the return path of the delta system is on one of the phases, it is directed to the phase of the wye source. Clearly, the phases are not evenly distributed at the source since neutral has to be the return path of current at the wye source. This return path of current will create a floating ground in the electrical system. A floating ground is a common connection in a circuit that provides a return path for current but is not connected to an earth ground. In the same fashion, disturbances at the source (wye) can not pass thorough neutral as the circuit is not completed with it. Since neutral is bonded to the ground at the main panel, resultant unwanted current at this point will go to the ground. The consequence is a ground loop. If the ground is not in a loop and is bonded only to the ground rod, then the return current will be on one of the phases of source and the transformer. This will lead to imbalance in the phase distribution and harm the load.
> 
> *Wye system (Load) connected to Delta system (Source)*:
> Assume wye load is connected to delta source in an electrical distribution system:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> At the load end, the return current takes the neutral path. But the neutral of the wye load has no connection to the delta source. The neutral at the load is connected to the ground. Now the return path of current is through the ground wire at the load. It creates ground loops in the electrical system, and this causes the ground wire to carry current in the electrical system. This phenomenon breaks all laws of fundamental electricity. Ground is designed for safety and it should not carry any current.


I don't know where this came from, but it's pure garbage. Look closely at the 'Ground Carrying Current'. Just exactly where does the current going to ground get back to any of the phases? It doesn't. 

I'b be willing to bet just about anything that nationwide there's well over 1 million delta wound motors connected to wye sources. If this article is true, why are any of them still in operation? 

Most motors over 15 or 20 HP are delta wound, smaller ones are wye. A large portion of them are operated on 480 volts. A very large portion of 480 volt systems are wye. 

It's pretty obvious to me that the article was written by an engineer who needed to make a boat payment, so he decided to write something sensational. The fact that it has absolutely no basis in reality doesn't matter, he got paid for it.

Rob


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## HARRY304E

The magnetic field around a conductor can be described by flux and flux density. Flux (Φ) can be assumed as magnetic fields around a conductor, and flows on the surface of the conductor. In simple terms, it is magnetically analogous to electrical current. Gauss's law sates that the flux of the electrical field out of a closed surface is proportional to the electrical charge


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## Jlarson

I read all that a couple times and it got stupider with each read



micromind said:


> It's pretty obvious to me that the article was written by an engineer


Man I hate those guys :laughing:


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## HARRY304E

Jlarson said:


> I read all that a couple times and it got stupider with each read
> 
> 
> 
> Man I hate those guys :laughing:


:laughing::laughing:


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## micromind

Jlarson said:


> I read all that a couple times and it got stupider with each read
> 
> 
> 
> Man I hate those guys :laughing:


Ever notice that the larger the ego, the smaller the brain?

I don't think engineer school teaches students anything at all about how to design electrical systems; instead it has only two goals.

1) To remove any trace of common sense from the student.

2) To instill the largest possible ego in said student.

The reason most electrical rooms have double doors has very little to do with access to equipment, instead it is the only way the engineer can get his ego into the room.

Ok, I'm done with my rant now.

Rob


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## Jlarson

micromind said:


> The reason most electrical rooms have double doors has very little to do with access to equipment, instead it is the only way the engineer can get his ego into the room.


:lol: :lol:


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## HARRY304E

micromind said:


> Ever notice that the larger the ego, the smaller the brain?
> 
> I don't think engineer school teaches students anything at all about how to design electrical systems; instead it has only two goals.
> 
> 1) To remove any trace of common sense from the student.
> 
> 2) To instill the largest possible ego in said student.
> 
> The reason most electrical rooms have double doors has very little to do with access to equipment, instead it is the only way the engineer can get his ego into the room.
> 
> Ok, I'm done with my rant now.
> 
> Rob





> The reason most electrical rooms have double doors has very little to do with access to equipment, instead it is the only way the engineer can get his ego into the room


only if he has the Keys.:laughing::laughing:


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## RePhase277

mcclary's electrical said:


> According to the nature of a delta system, it will allow one of the opposite conductors for the return path of current. The fundamentals of an electric circuit say that a circuit has to be completed (circled) in order to deliver power from the source to the load. When the return path of the delta system is on one of the phases, it is directed to the phase of the wye source. Clearly, the phases are not evenly distributed at the source since neutral has to be the return path of current at the wye source. This return path of current will create a floating ground in the electrical system. A floating ground is a common connection in a circuit that provides a return path for current but is not connected to an earth ground. In the same fashion, disturbances at the source (wye) can not pass thorough neutral as the circuit is not completed with it. Since neutral is bonded to the ground at the main panel, resultant unwanted current at this point will go to the ground. The consequence is a ground loop. If the ground is not in a loop and is bonded only to the ground rod, then the return current will be on one of the phases of source and the transformer. This will lead to imbalance in the phase distribution and harm the load.
> 
> *Wye system (Load) connected to Delta system (Source)*:
> Assume wye load is connected to delta source in an electrical distribution system:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> At the load end, the return current takes the neutral path. But the neutral of the wye load has no connection to the delta source. The neutral at the load is connected to the ground. Now the return path of current is through the ground wire at the load. It creates ground loops in the electrical system, and this causes the ground wire to carry current in the electrical system. This phenomenon breaks all laws of fundamental electricity. Ground is designed for safety and it should not carry any current.


:blink::blink::no:


:laughing::laughing::laughing::laughing: That is just too funny! It really makes no sense, grammatically or electrically!


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## Jlarson

This stuff appears to come from here http://www.epuniversity.org/, no mention of an author or referenced sources anywhere.


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## frenchelectrican

I have no issue with delta hooked up motor on wye supply over in Europe area and we are slowly drop out the Y/D starter setup to VSD to simpleifed the connections.

with Wye hooked up motor as long the nameplate stated wye connection it is not a issue as well.

Merci,
Marc


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## Frank Mc

mcclary's electrical said:


> *Problems with using incorrect electrical configurations*:
> 
> The electrical configuration of the source and the load should be same under any circumstances. That is, a Delta load should be connected to only a delta source and a Wye load should only be connected to a wye source. They should not be switched irrespective of the occasion.
> 
> *Delta system (Load) connected to Wye system (Source)*:
> 
> Assume a Delta load is connected to Wye source in an electrical distribution system.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> According to the nature of a delta system, it will allow one of the opposite conductors for the return path of current. The fundamentals of an electric circuit say that a circuit has to be completed (circled) in order to deliver power from the source to the load. When the return path of the delta system is on one of the phases, it is directed to the phase of the wye source. Clearly, the phases are not evenly distributed at the source since neutral has to be the return path of current at the wye source. This return path of current will create a floating ground in the electrical system. A floating ground is a common connection in a circuit that provides a return path for current but is not connected to an earth ground. In the same fashion, disturbances at the source (wye) can not pass thorough neutral as the circuit is not completed with it. Since neutral is bonded to the ground at the main panel, resultant unwanted current at this point will go to the ground. The consequence is a ground loop. If the ground is not in a loop and is bonded only to the ground rod, then the return current will be on one of the phases of source and the transformer. This will lead to imbalance in the phase distribution and harm the load.
> 
> *Wye system (Load) connected to Delta system (Source)*:
> Assume wye load is connected to delta source in an electrical distribution system:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> At the load end, the return current takes the neutral path. But the neutral of the wye load has no connection to the delta source. The neutral at the load is connected to the ground. Now the return path of current is through the ground wire at the load. It creates ground loops in the electrical system, and this causes the ground wire to carry current in the electrical system. This phenomenon breaks all laws of fundamental electricity. Ground is designed for safety and it should not carry any current.


Our supply system here in Oz is star (wye) and its quite common to connect delta motors to it no problem....

Frank


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## McClary’s Electrical

Frank Mc said:


> Our supply system here in Oz is star (wye) and its quite common to connect delta motors to it no problem....
> 
> Frank


 

I dug up something to read because I knew you guys wouldn't just take my word for it. I've seen the problems, and CORRECTED the problems with my own eyes. If anybody's "guessing", I think it most of the posters in this thread, as I have witnessed it first hand.


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## RePhase277

mcclary's electrical said:


> I dug up something to read because I knew you guys wouldn't just take my word for it. I've seen the problems, and CORRECTED the problems with my own eyes. If anybody's "guessing", I think it most of the posters in this thread, as I have witnessed it first hand.


I personally don't doubt that you have corrected problems with motors. I just don't think the problem was as you think it was. You did something and it _worked_ but may not have necessarily been the problem to begin with.

The stuff you posted as a reference is pure nonsense, from a simple physics perspective, let alone actual practice.


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## McClary’s Electrical

InPhase277 said:


> I personally don't doubt that you have corrected problems with motors. I just don't think the problem was as you think it was. You did something and it _worked_ but may not have necessarily been the problem to begin with.
> 
> The stuff you posted as a reference is pure nonsense, from a simple physics perspective, let alone actual practice.


 

The problem was this: The brand new machine at start up would not lift heavy logs. The equpiment tech was adjusting hydraulic pressure, and noticed that if he adjusted the relief anything valve over 1500 PSI, the motor would stall down to zero speed. He SWORE up and down that he should be able to turn the pressure all the way up to 2500 without overloading the motor. When I arrived I witnessed the stalling of the motor to zero speed several times by simply turning the relief valve. The motor is a Wye/delta motor 100 hp. 480 volt delta source. The motor upon installation had been wired for wye. I reconfigured for Delta and it instantly could be turned up to 2500 psi without stalling. Now, I have to imagine, if this motor had ONLY been wye, and had not been able to be reconfigure for Delta, I believe the motor would not have ran with a contactor. It would have needed a VFD, or a transformer.



I agree a delta motor would run on a wye source, but a Wye motor on delta source won't produce the normal torque. It will run, but not like it is supposed to.


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## micromind

mcclary's electrical said:


> The problem was this: The brand new machine at start up would not lift heavy logs. The equpiment tech was adjusting hydraulic pressure, and noticed that if he adjusted the relief anything valve over 1500 PSI, the motor would stall down to zero speed. He SWORE up and down that he should be able to turn the pressure all the way up to 2500 without overloading the motor. When I arrived I witnessed the stalling of the motor to zero speed several times by simply turning the relief valve. The motor is a Wye/delta motor 100 hp. 480 volt delta source. The motor upon installation had been wired for wye. I reconfigured for Delta and it instantly could be turned up to 2500 psi without stalling. Now, I have to imagine, if this motor had ONLY been wye, and had not been able to be reconfigure for Delta, I believe the motor would not have ran with a contactor. It would have needed a VFD, or a transformer.
> 
> 
> 
> I agree a delta motor would run on a wye source, but a Wye motor on delta source won't produce the normal torque. It will run, but not like it is supposed to.


I've seen the same thing; if the motor can be connected wye or delta and it is connected wye, it'll produce about 1/3 of its rated HP. If it is connected delta, it'll produce its full rated HP.

I've connected hundreds of wye wound motors to 240 delta systems; all without issue. The vast majority of these motors were 9 lead wye wound, and most of the systems were 4 wire (with a high leg). About half were closed delta (3 transformers) the other half were open (two transformers).

Rob


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## John Valdes

I agree with Rob. Completely. I have been connecting motors for over 35 years and never ever have given any thought to how the incoming power source is configured. Its a simple matter that you have a voltage source of three balanced legs. Connecting the motor to the source is determined in the pecker head, not the source.

Jerry. When you re-connected the motor for delta run configuration, all you did was connect it the right way. The person that wired it for "wye" was wrong. In this instance the current looks fine (very low) but the HP is almost cut in half.
The power/voltage source had zero influence on the motor. Only the way the motor was connected.


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## McClary’s Electrical

John Valdes said:


> I agree with Rob. Completely. I have been connecting motors for over 35 years and never ever have given any thought to how the incoming power source is configured. Its a simple matter that you have a voltage source of three balanced legs. Connecting the motor to the source is determined in the pecker head, not the source.
> 
> Jerry. When you re-connected the motor for delta run configuration, all you did was connect it the right way. The person that wired it for "wye" was wrong. In this instance the current looks fine (very low) but the HP is almost cut in half.
> The power/voltage source had zero influence on the motor. Only the way the motor was connected.


 

Yes, but it makes me think that if the motor had been strictly WYE, I would not have been able to get it running.


I always pay attention to your post about motors and drives, so what if this motor was not re-configurable? What then?


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## micromind

If the motor would have been wound wye, then it would have run properly on the voltage it was connected for. 

The vast majority of wye wound motors are dual voltage 9 leads. There are 6 coils inside the motor, each with 2 ends for a total of 12 wires. If the motor is rated for 230/460 volts, each coil is 133 volts. Only 9 (T1 through T9) are brought out because the other 3 (T10, T11, and T12) are always spliced together. These motors cannot be connected delta, they are wye only. (This is the internal connection of the motor, not the power source). 

If all 12 leads are brought out, the motor can be connected either wye or delta. This motor also has 6 coils. If this motor is rated 230/460, each coil is 230 volts. If this motor is connected in a series delta, it has two coils in series for each phase, so in order to produce its full rated HP it needs to see a supply of 460 volts phase to phase. 

This 12 lead motor can be connected wye as well, but the wye connection is used only for starting, not running. If this motor is connected series wye, it'd have 4 coils in series with each phase. In order to produce its rated HP in this configuration, the supply would need to be 796 volts. Each coil is designed for 230 volts but only 133 are applied; thus lower current and lower HP.

The reason for voltages like 133 and 796 is the same reason a wye supply connection is 120/208 and 277/480. A 120/240 or 240/480 wye cannot exist. 

Rob

P.S. Looking over this post, it seems somewhat confusing; I'd be surprised if anyone actually gets it. lol.

Maybe I should have paid more attention in high school english class!


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## John Valdes

mcclary's electrical said:


> Yes, but it makes me think that if the motor had been strictly WYE, I would not have been able to get it running.
> I always pay attention to your post about motors and drives, so what if this motor was not re-configurable? What then?


It would not matter as long as you have the correct voltage for the motor. Read Robs response as I could not make it more clear.


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## mrmike

John Valdes said:


> I agree with Rob. Completely. I have been connecting motors for over 35 years and never ever have given any thought to how the incoming power source is configured. Its a simple matter that you have a voltage source of three balanced legs. Connecting the motor to the source is determined in the pecker head, not the source.
> 
> Jerry. When you re-connected the motor for delta run configuration, all you did was connect it the right way. The person that wired it for "wye" was wrong. In this instance the current looks fine (very low) but the HP is almost cut in half.
> The power/voltage source had zero influence on the motor. Only the way the motor was connected.


 

I completly agree here also- as I have also wired up hundreds of 3 phase motors, and it makes me smile to hear someone call it a pecker head !!!:laughing: Ha Ha! That is what we always called em, but we had to call them a motor connection box in front of the "higher ups" :thumbsup:


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## BBQ

mcclary's electrical said:


> I dug up something to read because I knew you guys wouldn't just take my word for it. I've seen the problems, and CORRECTED the problems with my own eyes. If anybody's "guessing", I think it most of the posters in this thread, as I have witnessed it first hand.


Dude, there was more to it or you saw it wrong.


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## Motorwinder

You always need to check the name plate. 

Does it have only one voltage rating? If it does, then it's wye start, delta run.

If it has 2 voltages, like a lot of euro motors, then it's delta low voltage, wye high voltage.


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## McClary’s Electrical

Motorwinder said:


> You always need to check the name plate.
> 
> Does it have only one voltage rating? If it does, then it's wye start, delta run.
> 
> If it has 2 voltages, like a lot of euro motors, then it's delta low voltage, wye high voltage.


 

So are the graphs in post 17 just some garbage somebody made up?


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## BBQ

mcclary's electrical said:


> So are the graphs in post 17 just some garbage somebody made up?


I don't think they are what you think they are.


Here is a visual aid.








In the picture are three hots from a 3 phase source, using the meter can you tell me if the source is delta or wye?

Remember that motor coils are never intentionally connected to ground so the only tests you can do are line to line.


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## John Valdes

BBQ said:


> I don't think they are what you think they are.
> 
> 
> Here is a visual aid.
> 
> In the picture are three hots from a 3 phase source, using the meter can you tell me if the source is delta or wye?​
> Remember that motor coils are never intentionally connected to ground so the only tests you can do are line to line.


Excellent example. Very good! :thumbsup:


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## Motorwinder

BBQ said:


> I don't think they are what you think they are.
> 
> 
> Here is a visual aid.
> 
> 
> 
> 
> 
> 
> 
> 
> In the picture are three hots from a 3 phase source, using the meter can you tell me if the source is delta or wye?
> 
> Remember that motor coils are never intentionally connected to ground so the only tests you can do are line to line.


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## ropewalker1

Wye start Delta run Systems are sold for a reason !


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## John Valdes

ropewalker1 said:


> Wye start Delta run Systems are sold for a reason !


 But the smart consumer spends less money on a soft start. Wye/Start Delta/Run configurations are expensive, outdated, and very hard for MANY electricians to figure out. Anyone that ever had to reconnect a motor to this system knows exactly what I am talking about. And it does not matter if the leads are marked 1-6 either. :yes:


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