Bently Nevada 330878-90-00 Precision 50 mm Proximitor® Sensor

In the realm of industrial machinery protection, precise measurement is non-negotiable. The Bently Nevada 330878-90-00 is a high-performance 3300 XL 50 mm Proximitor® Sensor designed for critical differential expansion (DE) and rotor expansion (RX) monitoring in large rotating machinery . As part of the trusted 3300 XL series, this sensor provides the longest linear range in the eddy current transducer line, making it the industry standard for steam turbine generators and other heavy equipment .

Decoding the Part Number: 330878-90-00

Understanding the part number is key to ensuring you have the correct component for your system:

330878: Identifies this as a 3300 XL 50 mm Proximitor® Sensor .

-90: Specifies a 9.0 meter (29.5 feet) system length and a panel mount configuration for the Proximitor .

-00: Indicates the unit comes with no specific agency approvals, offering a standard, versatile option for global installations .

Unmatched Performance for Expansion Monitoring

The 330878-90-00 is purpose-built to measure the minute changes in position caused by the thermal growth of turbine rotors relative to their casings. Its defining feature is its exceptional 27.9 mm (1100 mils) linear range, which allows for accurate monitoring even during significant axial shaft movement .

Key Technical Specifications

System Linear Range: 27.9 mm (1100 mils), ideal for DE and RX applications .

Output Signal: 0.394 V/mm (10 mV/mil), ensuring backward compatibility with legacy 7200 and 50 mm DE systems for easy upgrades .

Temperature Tolerance: The probe can operate continuously up to 200 °C (392 °F) and withstand intermittent temperatures up to 250 °C (482 °F) .

Total System Length: 9.0 meters (29.5 feet) .

Built for the Harshest Environments

Steam turbine environments are unforgiving, but the 3300 XL 50 mm system is engineered to survive. The probe features a rugged design with both front and rear seals combined with a High-Temperature FluidLoc® cable to prevent moisture ingress . The special high-temperature ClickLoc® connectors ensure reliable signal transmission and feature a removable collar for easier cable routing through tight spaces .

Seamless Integration and Applications

Designed as a direct replacement for older systems, the 330878-90-00 allows facilities to upgrade their monitoring capabilities without changing their existing monitor configurations . It is primarily used for:

Differential Expansion (DE): Monitoring the expansion difference between the rotor and stator in large steam turbines .

Rotor Expansion (RX): Tracking the overall thermal growth of the rotor shaft.

For facilities relying on Bently Nevada 3500 monitoring systems, this sensor provides the critical, real-time data needed to prevent catastrophic contact between rotating and stationary parts.

Keywords: Bently Nevada 330878-90-00, 3300 XL Proximitor Sensor, 50 mm Proximity Transducer, Differential Expansion Sensor, Rotor Expansion Monitoring, Steam Turbine Protection, Bently Nevada 3300 Series, Industrial Vibration Sensor, Machinery Protection Systems, TSI Components.