Table of Contents

• 200350 Accelerometer Fault Entry
• 200350 Accelerometer Fault Symptoms
• Fault Diagnosis Thinking Process
• Common Causes of 200350 Signal Fault
• Advanced Diagnostic Methods
• Corrective Actions and Repair
• Real Troubleshooting Case
• Troubleshooting FAQ
• Final Technical Summary

200350 Accelerometer Fault Entry

Bently Nevada 200350-00-00-01 accelerometer signal problems are rarely caused by the sensor itself. In over 80% of field cases, faults originate from installation issues, grounding errors, or external interference.

200350 Accelerometer Fault Symptoms

• Constant high vibration reading with no mechanical issue
• Signal noise or unstable waveform
• Sudden spikes during motor startup
• Flatline signal (0 output or constant bias)

Fault Diagnosis Thinking Process

Instead of replacing the accelerometer immediately, follow a layered diagnostic approach:

• Step 1: Verify signal (electrical)
• Step 2: Verify mounting (mechanical)
• Step 3: Verify environment (EMI / grounding)

  // Diagnosis Logic
  IF Output = Constant THEN
      Check_Power_And_Bias();
  ELSE IF Noise_Level_High THEN
      Check_Shielding_And_Routing();
  ELSE IF Value_Too_High THEN
      Inspect_Mounting_Stiffness();
  END_IF;
  

Common Causes of 200350 Signal Fault

• Poor mechanical mounting (loose or soft surface)
• Ground loop or improper shielding
• Cable damage or connector oxidation
• Electromagnetic interference from VFD or motors
• Incorrect system configuration (wrong sensitivity)

Advanced Diagnostic Methods

• Measure bias voltage (typically -8V to -12V)
• Use oscilloscope to check waveform stability
• Perform tap test to verify sensor response
• Swap channel to isolate system vs sensor issue

Corrective Actions and Repair

• Reinstall sensor with proper stud mounting
• Improve cable shielding and grounding
• Replace damaged connectors or cables
• Reconfigure system input parameters

Real Troubleshooting Case

In a turbine monitoring system, persistent alarm was triggered despite stable operation:

• Reading: 9.5 mm/s RMS (normal should be ~3 mm/s)
• Waveform showed random spikes

We traced the issue step-by-step:

• Electrical check: OK
• Mounting: sensor installed on thin cover plate

After relocating sensor to bearing housing:

• Reading dropped to 3.1 mm/s
• Noise eliminated

Troubleshooting FAQ

Why is my signal flat at a constant voltage?

This usually indicates power supply or wiring issue. Check bias voltage and cable continuity.

Can EMI really affect accelerometer signals?

Yes. Especially near VFD drives, EMI can introduce high-frequency noise into low-level vibration signals.

How do I confirm the sensor is working?

Perform a tap test and observe waveform response. A healthy sensor will produce clear transient spikes.

Final Technical Summary

The Bently Nevada 200350-00-00-01 Troubleshooting Guide shows that accurate fault diagnosis depends on structured thinking rather than component replacement. Most issues can be resolved by correcting installation and signal path problems.