# low voltage running of High voltage induction motor

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### #1 saraswat

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Posted 16 October 2005 - 08:45 PM

Res Sir
I wanted to connect a 6.6 kv 360 KW 50Hz ind motor to 415 V source to heat the motor to improve its IR value, is it a correct method, if yes, what should br=e the source selection . pl guide.
saraswat

### #2 jraef

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Posted 18 October 2005 - 04:41 PM

Are you refering to heating the motor up prior to starting it on 6.6kV?

Why would you want to do that?
"He's not dead, he's just pinin' for the fjords!"

### #3 johnbose

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Posted 29 November 2005 - 11:13 AM

Yes you can apply 415V with locked rotor to a 6.6KV induction motor to improve its megger value as long as you do not exceed the locked rotor withstand current and time. If u can get hold of the factory test certificate for locked rotor current you can get the information on what voltage gives locked rotor current. From this you can find out what will be the current for 415 Volts. If this is within the full load current of the motor you are safe to do this. But before trying this why dont you use a hot air blower after opening one side.

### #4 petronila

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Posted 01 December 2005 - 07:49 PM

Hello Saraswat,

I think the better and safe way is using space heaters, the heaters could keep warm the windings once are de energized in order to avoid humidity. you can take inside stator sizes and make some calculations.

You can find this heaters to 440 Volts, you need to calculate the proper watt, the flat type can be installed on both Winding heads glued with silicon or fixed with cord.

For Large motors you can use this formula: W= 2DL . W= Watts, D= Outside Stator diameter in Inches and L= Core Lenght in Inches. Please take account the units due to maybe you need to perform some changes.

Regards

Petronila

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### #5 petronila

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Posted 01 December 2005 - 07:50 PM

Hello Saraswat,

I think the better and safe way is using space heaters, the heaters could keep warm the windings once are de energized in order to avoid humidity. you can take inside stator sizes and make some calculations.

You can find this heaters to 440 Volts, you need to calculate the proper watt, the flat type can be installed on both Winding heads glued with silicone or fixed with cord.

For Large motors you can use this formula: W= 2DL . W= Watts, D= Outside Stator diameter in Inches and L= Core Lenght in Inches. Please take account the units due to maybe you need to perform some changes.

Regards

Petronila

Take acount

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