The Bently Nevada 330881-28-05-080-00-02, also cataloged as the 330881 Proximity Transducer, serves as the primary PROXPAC XL Proximity Transducer utilized to execute non-contacting shaft displacement and vibration monitoring across machinery protection platforms.

Model Suffix Matrix

The 330881-28-05-080-00-02 identifier specifies the following physical and electrical configuration parameters: an 8 mm probe tip diameter, 3/8-24 UNF thread pitch, 8.0 meter cable length, and standard industrial termination. This unit integrates the Proximitor sensing electronics directly with the probe, eliminating the need for a separate signal conditioning housing.

Hardware Specifications

Mechanical Monitoring & Eddy-Current Transduction

Optimal system performance is defined by the precise scaling of eddy-current probes against rotating shafts. To ensure accurate rotor dynamics data, the transducer must be mounted to achieve a nominal gap voltage of -10 VDC. Deviation from this target influences the linearity of the output signal. Furthermore, cross-talk suppression must be implemented by maintaining minimum physical spacing between neighboring probes to avoid interference between high-frequency electromagnetic fields.

## Ordering info

• 1x 330881-28-05-080-00-02 PROXPAC XL Transducer

• 1x Protective connector cover

• 1x Installation technical manual

• 1x Calibration verification data sheet

Field Installation Guidelines

• Mechanical Interface: Ensure the mounting boss is drilled and tapped square to the shaft centerline to prevent angular alignment errors.

• Torque Protocol: Tighten the lock nut to 5.1 N-m (45 in-lb) to ensure mechanical stability. Excessive torque may cause thread deformation.

• Cable Protection: Protect the integral coaxial cable from mechanical abrasion and maintain a minimum bend radius of 25 mm to prevent center conductor fatigue.

• Grounding: Secure the probe case to the machine structure. Ensure the signal shield remains isolated from the machine ground at the termination point to prevent noise injection.

Frequently Asked Questions

• Can the integral cable be field-shortened? No, the system is calibrated for the specific cable length; cutting or extending the cable permanently alters impedance and accuracy.

• What is the target material requirement? Calibration is optimized for AISI 4140 steel; measuring other conductive materials will introduce measurement errors.

• How is the probe protected from impact? The PPS tip is chemically resistant but sensitive to mechanical force; ensure the probe is fully retracted during maintenance.

• Can this transducer be hot-swapped? No, system power must be disconnected at the terminal block before removing the device to prevent circuit damage.

• What occurs if the probe tip contacts the target? Potential destruction of the tip and permanent loss of signal linearity due to mechanical deformation.

• Is the device suitable for explosive atmospheres? Yes, when installed according to the Bently Nevada control drawings for intrinsically safe operation.

• How is signal clipping handled? If the gap exceeds the linear range, the output signal will saturate at the power supply rail.

• Why is the -10 VDC gap necessary? It centers the operating point within the transducer's linear response region for maximum dynamic range.