# 2 speed one winding motor



## John Valdes (May 17, 2007)

Sorry I did not see two speed as you used it in your title.


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## Soilentblue9 (Apr 11, 2014)

John Valdes said:


> Do you have a drive, or a two speed motor?




2 speed motor. 2 separate starters 3 pole for slow speed 5 pole for fast


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## John Valdes (May 17, 2007)

Check current at both speeds yet?
If yes, are they in line with nameplate current?

Did this motor run okay with the last batch of thick paint? 
An OL issue or a setup issue on the starter and OL relay.
This should be easy.
if you saw a red glow, you are having a serious OL issue. The OL should trip long before that would happen.


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## JRaef (Mar 23, 2009)

Has anyone worked on the motor recently? In my experience, it's very easy for an inexperienced electrician (or millwright who THINKS he's an electrician) to mis-connect a 2S1W motor. Plus there are 3 different TYPES of 2S1W connections: Constant Torque, Variable Torque and Constant HP. Get that wrong on a re-connect and you can get yourself in trouble.


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## Soilentblue9 (Apr 11, 2014)

JRaef said:


> Has anyone worked on the motor recently? In my experience, it's very easy for an inexperienced electrician (or millwright who THINKS he's an electrician) to mis-connect a 2S1W motor. Plus there are 3 different TYPES of 2S1W connections: Constant Torque, Variable Torque and Constant HP. Get that wrong on a re-connect and you can get yourself in trouble.




Yes maintenance had been working on it for a few weeks before I got involved. I believe it's a constant torque because of the way the windings are connected. If the motor wasn't put back the way it was taken apart, like for instance 2 phases were swapped so that it reversed rotation when moving to hi speed, could that cause the excessive current?


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## varmit (Apr 19, 2009)

Soilentblue9 said:


> Yes maintenance had been working on it for a few weeks before I got involved. I believe it's a constant torque because of the way the windings are connected. If the motor wasn't put back the way it was taken apart, like for instance 2 phases were swapped so that it reversed rotation when moving to hi speed, could that cause the excessive current?
> 
> 
> Sent from my iPhone using Tapatalk


Yes, and other bad things.

Meg the motor.

If "strange sounds are coming from the motor", there could be bearing or other mechanical problems.

I would check the motor connections. Never assume that others folks did their job correctly.


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## telsa (May 22, 2015)

Soilentblue9 said:


> 2 speed motor. 2 separate starters 3 pole for slow speed 5 pole for fast
> 
> 
> Sent from my iPhone using Tapatalk


I always associate more poles with slower rotation... and higher torque.

Straighten me out.


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## Soilentblue9 (Apr 11, 2014)

telsa said:


> I always associate more poles with slower rotation... and higher torque.
> 
> Straighten me out.




Sorry about that I could see how that would be confusing. How about sets of power contacts for each motor starter. 3 sets for slow 5 sets for fast. The 2 extra sets on the fast speed connect t1 t2 and t3 which leads me to believe it's constant torque. 


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## MDShunk (Jan 7, 2007)

I've seen 2-speed motors that were recently changed burned up far more often than any other type of motor. So many people see two starters and wire it like it's a 2-speed, 2-winding motor instead of a single winding motor. The starters actually "rearrange the wiring", so to speak, rather than simply pulling in three phases. Look at the drawing in the starter bucket and look at the drawing in the peckerhead cover and see where the issue is.


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## Soilentblue9 (Apr 11, 2014)

MDShunk said:


> I've seen 2-speed motors that were recently changed burned up far more often than any other type of motor. So many people see two starters and wire it like it's a 2-speed, 2-winding motor instead of a single winding motor. The starters actually "rearrange the wiring", so to speak, rather than simply pulling in three phases. Look at the drawing in the starter bucket and look at the drawing in the peckerhead cover and see where the issue is.




Good to know for the next time thanks for all the replies. Talked with maintenance Mgr earlier. They had pulled the belt off so the motor was isolated from the load. Slow speed measured around 26 amps on all 3 phases, fast speed stayed around 16-17 amps. Looks like they've just been putting to thick of batches in the mixer.


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## Bird dog (Oct 27, 2015)

Soilentblue9 said:


> Good to know for the next time thanks for all the replies. Talked with maintenance Mgr earlier. They had pulled the belt off so the motor was isolated from the load. Slow speed measured around 26 amps on all 3 phases, fast speed stayed around 16-17 amps. Looks like they've just been putting to thick of batches in the mixer.
> 
> 
> Sent from my iPhone using Tapatalk


May be they should start weighing the batches & establish a maximum load.


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## MDShunk (Jan 7, 2007)

or put the right gearbox on. It's not unusual to see tank mixer gearboxes in the 100:1 range and greater.


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## MDShunk (Jan 7, 2007)

Soilentblue9 said:


> Slow speed measured around 26 amps on all 3 phases, fast speed stayed around 16-17 amps.


That seems a little backwards, to me at least. I guess the paint gets momentum at the high speed and stirs the paint itself and helps the agitator move along?. A typical dataplate for full load amps on a typical 20/5hp 2-speed motor would be around 26 amps on high speed and 12 amps on low speed, but I have no idea how fluid in motion may or may not affect current measurements at each speed.


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## JRaef (Mar 23, 2009)

Do you have the nameplate on the motor still? Because you can tell the configuration by the nameplate data.

*Constant Torque:* The nameplate will show two different HP ratings, the low speed is always 1/2 of the high speed and despite it having two HP ratings, the FLC for each speed is roughly the same.

*Variable Torque:* the low speed HP is 1/4 of the high speed HP, so the 20/5HP is an example of that.

*Constant HP:* The speed difference can vary by design, but the HP stays the same at either speed, so the torque / current difference is the same ratio as the speed difference, but inverse. There will be only one HP shown on the nameplate, so if the speed ratio is 2:1, the low speed current is twice what the high speed current is (because HP = tq (in ft. lbs) x RPM/5250 so for the HP to be the same, there must be twice as much torque at half the speed, and current follows torque).

The three different connection patterns are shown in the top row of diagrams here.


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## frenchelectrican (Mar 15, 2007)

Soilentblue9 said:


> Good to know for the next time thanks for all the replies. Talked with maintenance Mgr earlier. They had pulled the belt off so the motor was isolated from the load. Slow speed measured around 26 amps on all 3 phases, fast speed stayed around 16-17 amps. Looks like they've just been putting to thick of batches in the mixer.
> 
> 
> Sent from my iPhone using Tapatalk


The numbers what you posted dont sound right to me.

something is messed up on connection.

Please look at the motor nameplate and read all the details if the nameplate is there.

And pay attetion to all the conductors comming out of the motor to the peckerhead. 

Look at JRaef's photo of motor connection diagram there is few differnt verison you can hook up with two speed single winding motor. 

You need to know which conferation you going to use it and follow the nameplate to get the referice on connection. 

Most 2 spd 1 winding motor useally have 6 leads but some come in 12 leads ( if dual voltage type )


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