6 lead 2 speed motor

[bigmexican]

help !!!!!!!!!!!!!
troubleshooting 6 lead 2 speed motor 3 phase 480 volt.
I am not familiar with this motor and I would like to know if I have done the troubleshooting correctly. It is a 3 starter setup, high low speed, checked the all contactors, pulling all the wire off, and checked continuity between the starter and the overloads. Everything was good.
I checked the voltage at the pecker head and had good voltage. I also ohmed motor to case. It showed no ground. Checked ohmes on motor leads and it came out pretty close ranges between all leads. After all of this the motor is still not working properly. Low speed works fine. At high speeds it sounds like it is single phasing. Could there be a bad internal winding if everything checked out okay or can a winding be going bad? Or can you tell me if I am missing something? This is a 50 HP motor, when troubleshooted there was no load on the motor.

 

[edison123]

Please post all the motor name plate details.

* Women are like the police. They can have all the evidence in the world and yet they still want a confession - Chris Rock *

 

[Marke]

This is probably a Dahlander configuration where the motor is in delta connection for low speed and double star connection for high speed.

Do you have continuity between all six leads?

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[petronila]

Yes I am with Marke , this sounds like a dahlander motor so maybe you are wrong connected the motor, if you have 6 leads the high speed could be obtained in delta connection and the low speed in star this is true if the motor is constant horsepower but if the motor is constant torque the high speed be obtained in star and the low speed in delta.You could have another connection called Variable torque High (2 Wye) and Low (1 Wye)

Note:

Constant Horsepower the horsepower is the same in any speeds.

Constant Torque Low speed horsepower is the half of high speed power.

Variable Torque Low Speed horsepower is one fourth of high speed horsepower.

Regards

Petronila

 

[powerjunx]

You seem not familiar with this stuff, really. The fact some good boys out there rather mistakenly presume this as a simple wye-delta configuration,hence nothing the fact its 2 speed after a troubleshooting.
Marke has pointed out the great possibility of the machine's wiring configuration it's a dahlander motor connection. Try to find out the continuity of its lead in which the quickiest way to confirm.


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