Table of Contents

• 200350-02-00-CN Fault Diagnosis Entry
• Accelerometer Fault Symptoms
• Field Troubleshooting Logic
• Common Causes of IS Loop and Signal Fault
• Diagnostic Methods for 200350 Accelerometer
• Corrective Actions and Recovery
• Real Troubleshooting Case
• Troubleshooting FAQ
• Final Technical Summary

200350-02-00-CN Fault Diagnosis Entry

Bently Nevada 200350-02-00-CN accelerometer faults in hazardous environments are often linked to intrinsic safety loop issues rather than sensor failure. Incorrect barrier configuration or grounding errors frequently lead to unstable signals or false alarms.

Accelerometer Fault Symptoms

• Unstable vibration readings with random fluctuation
• Noise spikes during equipment startup
• Flatline signal due to loop interruption
• Signal drift over time

Field Troubleshooting Logic

Instead of immediate replacement, experienced engineers isolate faults using layered logic:

• Check intrinsic safety loop continuity
• Verify grounding scheme
• Evaluate environmental interference

  // IS Loop Diagnosis
  IF Signal_Fluctuation THEN
      Check_Grounding();
      Inspect_IS_Barrier();
  ELSE IF No_Signal THEN
      Verify_Loop_Continuity();
  ELSE
      Check_Mounting_Integrity();
  END_IF;
  

Common Causes of IS Loop and Signal Fault

• Improper intrinsic safety barrier wiring
• Ground loop caused by dual grounding points
• Shield connected at both ends
• EMI interference from nearby equipment
• Loose mounting affecting signal accuracy

Diagnostic Methods for 200350 Accelerometer

• Measure loop resistance and continuity
• Check bias voltage (-8V to -12V typical)
• Use oscilloscope to analyze waveform noise
• Temporarily bypass barrier (safe area test only)

Corrective Actions and Recovery

• Rewire intrinsic safety barrier correctly
• Implement single-point grounding
• Reconnect shielding at one end only
• Reinstall sensor if mounting is loose

Real Troubleshooting Case

In a petrochemical plant, persistent alarm occurred on a compressor:

• Reading fluctuated between 3–10 mm/s
• No mechanical fault detected

Root cause analysis:

• Barrier grounding connected to multiple points
• Shield grounded at both ends

After correction:

• Single-point grounding implemented
• Shield corrected

Result:

• Stable reading at 3.3 mm/s
• No further alarms

Troubleshooting FAQ

Why is my signal unstable in hazardous areas?

Most likely due to grounding or intrinsic safety barrier wiring issues rather than sensor failure.

Can I bypass the barrier for testing?

Only in safe area conditions and with proper safety procedures. Never bypass in hazardous zones.

How do I confirm grounding is correct?

Ensure only one grounding point exists for the signal loop and no parallel ground paths are present.

Final Technical Summary

The Bently Nevada 200350-02-00-CN Troubleshooting Guide highlights that most faults are related to intrinsic safety loop configuration and grounding. Proper diagnostic logic ensures accurate fault isolation and stable system operation.