Fault Zone Analysis ROTOR

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Fault Zone Analysis ROTOR

• Luis Leon
• PdMA Corporation
• Motor Reliability Technical Conference
• May 15-17, 2007 St. Petersburg, FL

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Objectives

• Discuss Rotor Fault Mechanisms
• Analysis Methods
• Case Studies

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Rotor Fault Mechanisms

• Thermal
• Magnetic
• Dynamic
• Environmental
• Mechanical
• Residual

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Thermal Damage
5
Excessive Load Cycling
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Broken Bars
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Broken Bars
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Mechanical Stress
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Several Motors to Examine

• In the following slides we will examine data from
  several different motors.
• The data collected includes EMAX and MCE data for
  rotor problems.

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Motor No. 1
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Demod
Fp
Speed Frequency
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Pole Pass Sidebands
50-49.341 0.659Hz
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Swirl Effect
.659Hz
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Motor No. 2
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In-Rush
Motor No. 2
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Pole Pass Sidebands
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Swirl Effect
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Motor No. 3
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Rotor Influence Check
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Demod
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Pole Pass Sidebands
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Swirl Effect
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Low Influence Rotor
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Inductance Trending
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Low Influence
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2 Years Later
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1 Month Later
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Healthy Rotor
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Use All Resources

• Take pictures of the motor with a digital camera
• Perform motor testing with MCEMAX
• Perform infrared imaging
• Perform vibration testing

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Summary

• Identify Fault Mechanism Before the Actual Fault
  Occurs
• Correlate Test Data
• Minimize Additional Damage