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Two Speed Motor

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debco99

Industrial
Mar 21, 2002
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Is it possible to use a vfd on a two speed motor? Can the motor be rewound or wired different to allow this.
 
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Hi Debco 99
In theory, if you have a two speed motor with two completely seperate windings, there is no reason that I can think that a vfd couldnt be used.
But I am not entirely sure about a motor with tapped windings.....I think that, as long as your vfd output voltage tallied up with the motor, that you should be able to run the motor OK..but,dont forget that, if you do try it, kaap tabs on the current draw, and make sure that you dont try to run the motor way too slow, as there will be little or no cooling effect!!

Jeff
 
Im in the process of retrofitting an old machine tool that had a two-speed motor and we decided to go ahad and use a vfd and was waiting fot this customer to ask "Why cant we use the old motor?" We have decided to replace it with a proper motor with encoder feedback. Thanks
 
debco99,

likewise, there isnt a way that the old machine couldnt be used for VFD's..

1.) If the motor is a dual winding dual speed, vfd is applicable.

2.) If the motor is a tapped winding dual speed, vfd is also applicable. This is used mostly in batching plant for agitation and mixing purposes.

it is noteworthy, that you must take all the neccesary data from the motor to match with your VFD like; voltage, current, rpm, frequency, etc. By using dual speed application of the machine, all VFD's have preset speeds ranging from 1 to 6 preset speeds.




 
The only problem I see is damage to the winding insulation and bearings, since the motor you have was not intended for VFD application. I guess your chances of success at 60%.
 
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