To identify the root cause of the increasing G levels at the Motor Drive End (DE) bearing, here’s a concise analysis:

Key Observations:

1. Motor RPM: 1500
2. Motor Type: Inverter driven, Variable Speed Drive
3. Machine Type: Hammer Mill
4. Bearing: SKF 6322
5. Peak-to-Peak G levels: Increased to 69 G’s at Motor DE bearing.
6. Spectral Data: Increased activity at both DE and NDE bearings, harmonics at 3.05 orders of motor turning speed frequency.
7. Direction: Radial (Vertical and Horizontal), Axial

Analysis:

Potential Faults:

1. Bearing Faults (SKF 6322):

   • Non-synchronous frequencies.
   • Increased activity at both DE and NDE bearings.

2. Electrical Faults:

   • Inverter-driven motor.
   • Harmonics at 3.05 orders suggest potential electrical issues.

Next Steps:

1. Inspect Bearings:

   • Check SKF 6322 bearings for wear, spalling, or defects.

2. Electrical Analysis:

   • Inspect the inverter drive and electrical connections for faults.

Conclusion:

The likely causes are bearing faults or electrical issues. Inspect the bearings and electrical components to confirm.

Would you like to proceed with these inspections, or do you have additional data to provide?

The fault is likely with the Outer Race of the SKF 6322 bearing (BPFO).

Recommendations:

1. Inspect the Outer Race of the SKF 6322 Bearing:
   • Look for signs of wear, spalling, or other defects.
2. Replace the Bearing if Necessary:
   • If defects are found, replace the bearing to prevent further damage and reduce vibration levels.
3. Monitor Vibration Levels:
   • Continue to monitor after replacing the bearing to ensure the issue is resolved.

Would you like to proceed with these steps?

The periodic grooves or ridges on the bearing outer race indicate fluting, caused by electrical discharge. This happens due to stray electrical currents passing through the bearing, often from:

1. Poor grounding.
2. Faulty insulation in motor windings.
3. Variable Frequency Drives (VFDs) or Inverter Drives.

Recommendations:

1. Inspect and Repair Grounding:

   • Ensure proper grounding of the motor and electrical system.

2. Install Insulated Bearings:

   • Consider insulated or hybrid ceramic bearings to prevent electrical currents from passing through.

3. Use Shaft Grounding Devices:

   • Install shaft grounding rings to divert electrical currents away from the bearings.

4. Regular Monitoring:

   • Implement a monitoring program to detect early signs of bearing damage.

Would you like to proceed with these recommendations?

You're welcome! Installing insulated bearings is a great step. Here are a few additional steps to ensure longevity and reliability:

Key Steps:

1. Verify Installation:

   • Ensure insulated bearings are installed correctly per manufacturer guidelines.

2. Check Grounding:

   • Verify proper grounding and bonding of the motor and electrical system.

3. Install Shaft Grounding Devices:

   • Consider shaft grounding devices to provide a safe path for electrical currents.

4. Regular Monitoring:

   • Implement a monitoring program using vibration analysis and other tools to detect early signs of wear or damage.
   • Schedule regular maintenance for inspections and servicing.

5. Review VFD Settings:

   • Optimize VFD settings to reduce high-frequency switching that can cause electrical discharge issues.

6. Lubrication:

   • Ensure proper lubrication according to manufacturer recommendations.

Follow-Up:

1. Monitor Performance:

   • Closely monitor motor and bearing performance for any changes in vibration, noise, or temperature.

2. Document Changes:

   • Keep detailed records of installation, maintenance, and monitoring activities.

By following these steps, you can enhance the reliability and performance of your machinery. If you need further assistance, feel free to reach out.