Table of Contents

• 200350-02-00-00 Accelerometer Fault Entry
• 200350 Accelerometer Fault Symptoms
• Fault Analysis Method (Field Logic)
• Common Causes of Accelerometer Fault
• Diagnostic Techniques and Measurements
• Corrective Actions and Repair Strategy
• Real Troubleshooting Case
• Troubleshooting FAQ
• Final Technical Summary

200350-02-00-00 Accelerometer Fault Entry

Bently Nevada 200350-02-00-00 accelerometer abnormal readings are often misinterpreted as machine faults. In practice, most issues originate from installation errors, grounding problems, or signal interference rather than real mechanical vibration.

200350 Accelerometer Fault Symptoms

• Unexpected high vibration values without mechanical change
• Irregular spikes in waveform
• Constant bias voltage with no dynamic signal
• Different readings between identical machines

Fault Analysis Method (Field Logic)

Experienced engineers do not replace the sensor first. Instead, they isolate the problem step by step:

• Check electrical signal → is bias stable?
• Check mechanical installation → is mounting rigid?
• Check environment → is EMI present?

  // Fault Isolation Logic
  IF Signal_Stable_But_High THEN
      Inspect_Mounting_And_Orientation();
  ELSE IF Signal_Noise THEN
      Check_Cable_Shielding();
  ELSE IF No_Output THEN
      Verify_Power_And_Continuity();
  END_IF;
  

Common Causes of Accelerometer Fault

• Loose or incorrect mounting direction
• Improper grounding causing noise pickup
• Damaged cable or connector
• EMI from variable frequency drives (VFD)
• Wrong system scaling or configuration

Diagnostic Techniques and Measurements

• Measure bias voltage (-8V to -12V typical)
• Use oscilloscope for waveform inspection
• Perform tap test to validate sensor response
• Swap channel input to isolate sensor vs system issue

Corrective Actions and Repair Strategy

• Reinstall sensor with proper orientation
• Improve mounting rigidity
• Replace or reroute cable
• Enhance grounding and shielding
• Reconfigure monitoring system parameters

Real Troubleshooting Case

In a compressor monitoring system, abnormal alarms occurred after maintenance:

• Reading increased from 3 mm/s to 8.7 mm/s
• No mechanical change observed

Diagnosis steps:

• Signal check: OK
• Mounting inspection: sensor slightly loose

After tightening and re-torquing:

• Reading returned to 3.2 mm/s
• System stable without alarms

Troubleshooting FAQ

Why does vibration increase after maintenance?

Often due to improper reinstallation of the accelerometer rather than actual machine issues.

How do I confirm EMI interference?

Observe waveform for high-frequency noise correlated with motor operation or inverter switching.

Should I replace the sensor immediately?

No. Always verify installation and signal path first. Sensor failure rate is relatively low.

Final Technical Summary

The Bently Nevada 200350-02-00-00 Troubleshooting Guide shows that structured fault diagnosis is essential. Most issues can be resolved through installation correction, not component replacement, ensuring reliable vibration monitoring in industrial systems.