The Bently Nevada 330881-28-00-125-07-02, also cataloged as the 330881 PROXPAC XL Proximity Transducer, operates as a dedicated hardware component for integrated eddy-current displacement sensing and signal conditioning within turbine monitoring (TSI) platforms.

Suffix Breakdown & Model Matrix

The 330881-28-00-125-07-02 follows the standard PROXPAC XL system configuration nomenclature:

• 330881: PROXPAC XL integrated proximity transducer.

• 28: Probe diameter/thread specification.

• 00: Unthreaded length (0 mm).

• 125: Total case length (125 mm).

• 07: Total system length (7.0 meters).

• 02: Agency approval and accessory option.

Hardware Specifications

Mechanical Monitoring Characteristics

The PROXPAC XL system integrates probe and Proximitor electronics, requiring precise eddy-current probe scaling to ensure linear output. During setup, gap voltage validation is mandatory; a target of -10 VDC at the monitor input is required to center the transducer in its linear operating region. The internal design features cross-talk suppression circuitry to prevent signal noise in high-density sensor arrays. This integration supports rotor dynamics monitoring, shaft centerline position, and radial vibration detection where simplified cabling and reduced installation complexity are required.

Ordering info

• One (1) 330881-28-00-125-07-02 PROXPAC XL Transducer.

• Mounting hardware (nuts and lock washers).

• Technical compliance and installation instruction sheet.

• Note: A stable -24 VDC power supply is required for signal accuracy.

Field Installation Guidelines

• Mechanical Interface: Mount the transducer through the machine case; use a rigid bracket to prevent mechanical resonance from affecting vibration data.

• Gap Setting: Utilize a depth micrometer to establish the mechanical gap; verify the output voltage at the signal terminal (Target: -10 VDC).

• Cabling: Install cabling in shielded conduit or cable trays; maintain physical separation from high-voltage AC lines to prevent induced electrical noise.

• Grounding: Establish a low-impedance machine ground for the transducer housing to ensure effective shielding of the internal signal circuitry.

• Thread Management: Apply torque to jam nuts as specified; verify that lock washers are correctly installed to prevent loosening caused by machine-induced harmonic vibration.

Frequently Asked Questions

• What is the primary benefit of the PROXPAC XL integrated design?

  Integration eliminates the need for separate external extension cables and remote Proximitor mounting, reducing installation footprint and cabling complexity.

• Does this transducer require an external Proximitor?

  No. The Proximitor electronics are permanently integrated within the transducer housing, allowing for a direct signal path to the monitoring system.

• What is the target gap voltage for this model?

  The nominal operating gap is centered at -10 VDC, ensuring the transducer functions within its specified linear sensing range for vibration measurement.

• Is the 7.0 meter system length field-adjustable?

  No. The system is calibrated as a single unit at the factory for the 7.0 meter length; any modification will invalidate the calibration.

• Can I replace the internal probe if damaged?

  No. The PROXPAC XL is a factory-sealed, integrated unit; failure of any component requires the replacement of the entire transducer assembly.

• How is the operational status verified?

  Status is verified by monitoring the DC output voltage; drifts or deviations from the nominal -10 VDC gap voltage may indicate probe or electronic failure.

• Is this transducer rated for hazardous area installation?

  The unit carries specific agency approvals; verify that the "02" suffix and system ratings align with your site's hazardous area classification requirements.

• Does this transducer require a specific target material?

  Yes. Factory calibration is based on 4140 steel. Using other shaft materials requires an adjustment to the scale factor to maintain measurement accuracy.