# Delta or Wye



## Jay Freeman (Aug 2, 2017)

The motor is a Siemens 1LE0001-2DB0 84 KW, FLA 123 A, 480v line and will be on a softstart.

The application is a huge mixer for dry ingredients... mostly powders. After the initial mixing, the mixer will be switched on every few minutes for about 5 or 10 seconds at a time.

Efficiency isn't that important but not destroying the mixing ribbon would be.

I'm thinking Wye config but I just figured I'd get some feedback here.

Thanks,
Jay


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## Navyguy (Mar 15, 2010)

My first question would be what is supplied?

Don't remember where I got this years ago (I would like to give credit)...

• Delta-Wye: Delta-Wye transformers are commonly found in industrial facilities. From an economical perspective, this setup is advantageous, since Delta configurations are associated with lesser amps (and less heat generation). Because of this, less insulation on the primary side is required. Smaller wiring on the primary coils can be utilized. On the secondary side, a neutral is provided.

• Wye-Delta: A Wye-Delta connection is found in three-wire transformer applications requiring a neutral and service of loads the secondary side. This type of configuration may promote harmonic disturbances. Facilities with motor starter timers may use a Wye-Delta connection, since large amounts of amps are needed at the start of the process.

• Wye-Wye: A Wye-wye connection is suitable for transformer applications that need a neutral on the primary side. The three-wire configuration can be used on three-phase and single-phase circuits. In the event one of the transformers fails prematurely or gets damaged, the entire system could become compromised.

• Delta-Delta: A Delta-Delta configuration is recommended for projects that does not need a neutral on the secondary side. Though one can be provided, which is called a high leg. This type of wiring may also be beneficial for operations that require a minor single-phase component. Should one of the three transformer components fail, the other two can continue to function at a lower output.

Cheers
John


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## Jay Freeman (Aug 2, 2017)

I'm talking about motor winding configuration.


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## gpop (May 14, 2018)

Jay Freeman said:


> I'm talking about motor winding configuration.


Depending on the motor but if its a standard whe-start delta-run motor then you need to wire it to run which would be delta as you are using a softstart.

I would probably contact siemens and tell that what you need the motor to do. Short runs like this could be a problem and you may need a motor driven fan to help get rid of the heat while its shut down.


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## paulengr (Oct 8, 2017)

Agreed with previous...you need delta (run) configuration. Also since it's starting under load you will be probably using current limit starting at say 350-450% of FLA. You can also torque limit but thats almost the same as current limiting. Either wauy, it will increase starting times way beyond typical 2-10 seconds. At 5-10 seconds it's never going to even reach full.speed so it will run at roughly 10 to 20 times rated heat load (i-squared x R) for every "pulse" and then try to cool down in between with no fan turning. The fan's air flow is proportional to the square of RPM so basically doing nothing at all to cool the motor since it never sees full speed. No way you're getting a fanless (TENV) motor at that size so plan on blower cooled or burn up a lot of motors learning this lesson. A VFD won't fix this either.



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## micromind (Aug 11, 2007)

If you connect a Y start - Delta run motor for Y, you'll get roughly 1/3 of its nameplate HP at full voltage. The Delta connection will give full HP. 

The Y connection is for starting only.


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## Navyguy (Mar 15, 2010)

Jay Freeman said:


> I'm talking about motor winding configuration.


Sorry... I totally misread that post...

Yes definitely WYE - DELTA start - run set-up. I am thinking you might be better off with a couple or three smaller motors if possible based on the previous comments. That motor won't even ramp-up to full speed in that time and depending on how thick the mixtures is still might be coasting to a stop when it starts again.

If you used two or three smaller motors you could alternate them to allow for faster on-off times while allowing for cooling. I have worked in food previously and perhaps the approach is wrong also. Perhaps you need to be rotating the drum. In a place where I worked previously where we had to mix dry ingredients we had basically what looked like a cement mixer drum. It constantly rotated and had a special configuration of flutes on the inside to make sure the heavier ingredients did not sink to the bottom. The drum lifted and dumped into a measuring type of injector machine every few minutes to keep it full. The drum rotated all day and was only stopped for sanitation at the end of the day.

Cheers
John


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## JRaef (Mar 23, 2009)

Are you referring to the connection options given for the Soft Starter, i.e. "Inside the Delta" or "Direct On Line" perhaps? That has to do with taking advantage of a motor DESIGNED for Y-Delta starting and using the fact that it has 6 leads coming out to the starter in order to reduce the size of the soft starter to save money. That is the ONLY benefit to doing that, all other aspects of it are risks. I NEVER recommend it, it's not worth it.


For those unfamiliar with the concept, you take all 6 leads of the motor, then using the Delta configuration, you wire the soft starter poles to be in SERIES with the windings, which means the soft starter only carries 58% of the motor current and can thereby be sized smaller / cheaper.












The main risk is that if even ONE of the SCRs shorts, current will flow in that winding and there is no way to stop it unless you have a way of detecting it AND a contactor (as shown above, which is optional). In a standard configuration, you would need for TWO SCRs in opposing phases to short before that would happen, and that is a rare occurrence.


Another detrimental aspect of this is the general unfamiliarity everyone has with it. If you understand it and can hook it up correctly, that's fine, but what about the next guy called out in the middle of the night to fix it who has never seen this done before? One wire error and the SCRs short, so more down time and whatever perceived savings go right out the window.


My advice, don't do it.


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## Jay Freeman (Aug 2, 2017)

Thanks for all the input.

I really appreciate it.


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## Naman Verma (Mar 22, 2018)

Basically the Y connections are used for Starting the motor as the staring current of motor is very high which is provided by the the Y connections and when motor attains its full speed then it starts running in Delta connection .So according to me the motor will be in Delta Connection...
Good Luck


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## tmessner (Apr 1, 2013)

Make sure the soft start is rated for the duty cycle. I think they are rated in starts per hour to dissipate heat. We also had to install a drive instead of a soft start on a 200 hp centrifugal fan because we could not get the fan up to speed before the timer ran out and dropped out the soft start.


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## Southeast Power (Jan 18, 2009)

Jay Freeman said:


> The motor is a Siemens 1LE0001-2DB0 84 KW, FLA 123 A, 480v line and will be on a softstart.
> 
> The application is a huge mixer for dry ingredients... mostly powders. After the initial mixing, the mixer will be switched on every few minutes for about 5 or 10 seconds at a time.
> 
> ...


Pardon my ignorance of the industry but,

Would it be at all possible to run the motor during the process and use a clutch to engage the mixer for the pulsing part of the mixing?


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## Jay Freeman (Aug 2, 2017)

Southeast Power said:


> Pardon my ignorance of the industry but,
> 
> Would it be at all possible to run the motor during the process and use a clutch to engage the mixer for the pulsing part of the mixing?


Not in this situation... as it is, the motor is run by a soft start and working fine.

As an experiment, I wired the motor in Wye config and tried it but the Soft Start didn't like that at all, so I put the motor back to Delta.


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## gpop (May 14, 2018)

Jay Freeman said:


> Not in this situation... as it is, the motor is run by a soft start and working fine.
> 
> As an experiment, I wired the motor in Wye config and tried it but the Soft Start didn't like that at all, so I put the motor back to Delta.


You kinda need to understand that a motor was designed to run at a certain voltage and speed.(volts per hertz) By wiring to wye you effectively sent half the voltage to each coil pack but you kept the speed. As nothing is free is life (full speed @ half voltage) the motor can not produce full power and as the load wasn't reduced its being overloaded.


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## Jay Freeman (Aug 2, 2017)

Well in this application, the motor will be started frequently and ran for about 10 seconds and stopped for about 5 to 10 minutes and started again etc... so I was wondering if Wye might be better but nope.


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## gpop (May 14, 2018)

Jay Freeman said:


> Well in this application, the motor will be started frequently and ran for about 10 seconds and stopped for about 5 to 10 minutes and started again etc... so I was wondering if Wye might be better but nope.


Out of interest how hot is the motor getting. Can you keep you hand on it for 30 seconds?


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