The Bently Nevada 330878-51-05 is a 3300 XL 50 mm Proximitor Sensor engineered for high-precision, non-contacting displacement monitoring. As part of the 3300 XL transducer system, this sensor is specifically designed to measure differential expansion (DE) or rotor expansion (RX) in large steam turbine generators, where significant axial movement occurs between the rotor and the machine casing.

Features

• Maximum linear range of 27.9 mm (1100 mils), providing the longest linear measurement capability in the Bently Nevada eddy current transducer portfolio.
• Consists of a 50 mm probe, extension cable, and the 3300 XL 50 mm Proximitor Sensor.
• Designed for high-accuracy tracking of extreme displacement in large rotating machinery.
• Features a 5.0-meter total system length and DIN-rail mounting configuration.
• Constructed with a durable A380 aluminum housing.

Applications

• Power Generation: Monitoring steam turbine rotor-casing differential expansion during thermal transients.
• Oil & Gas: High-precision position monitoring for large compressors and pumps.
• Heavy Industrial: Integration with 3500 series monitoring racks for stability analysis of large shafts.

Technical Specifications

Installation Guidelines

• Ensure the system is powered down before connecting or disconnecting the Proximitor sensor.
• The 50 mm probe requires a target area of at least 102 mm in diameter to maintain calibrated accuracy.
• For differential expansion measurements, ensure proper alignment of the transducer relative to the target collar or ramp.
• When installing in high-EMI environments, ensure shielded cables are routed away from high-voltage power lines.
• Verify that the system length (5.0m) matches the calibrated extension cable to maintain signal integrity.

FAQ

What is the primary function of the 330878-51-05?

This sensor is used for measuring differential expansion in large steam turbines, tracking the axial growth difference between the rotor and the stator.

What is the typical gap voltage?

Under normal operating conditions with the shaft centered, the gap voltage is typically between -9 V and -11 V DC.

Can this be used with other probe sizes?

No, this sensor is specifically calibrated for the 3300 XL 50 mm proximity probe and its matched extension cable system.