Bently Nevada 330878-91-05 3300 XL 50 mm Proximitor Sensor

Signal Conditioning for Extended Range Proximity Probes

The Bently Nevada 330878-91-05 Proximitor sensor provides dedicated signal conditioning for 3300 XL 50 mm proximity probe systems. This robust module converts the probe’s eddy-current signal into a proportional voltage output for monitoring and protection applications. The unit measures 101.6 mm in height, 44.5 mm in width, and 120.7 mm in depth, with a weight of approximately 570 grams. It operates on a -24 Vdc negative supply and delivers a standard -3.94 V/mm sensitivity output. This sensor enables accurate displacement measurements for large rotating machinery with extended gap requirements.

Extended Range Input and Output Characteristics

This Proximitor sensor provides a linear measurement range from 2.54 mm to 25.4 mm with a sensitivity of 3.94 mV/µm. It supports frequency responses from 0 to 10 kHz, capturing both static gap voltages and dynamic vibration components. The device accepts a target gap range of 3.8 mm to 12.7 mm from the probe tip to the shaft surface. Its output impedance measures 50 Ω, driving loads up to 10 mA without signal degradation. Such specifications make this sensor ideal for applications requiring larger standoff distances.

Detailed Technical Specifications

Mounting and Interface Configuration

This Proximitor includes a DIN-rail mounting bracket for straightforward installation in control cabinets or junction boxes. The terminal block accepts standard 22 AWG wires for power, probe input, and signal output connections. A front-panel BNC connector provides additional interface capability for diagnostic equipment and calibration tools. The unit stores negligible internal energy, supporting intrinsic safety ratings for hazardous zone installations. Users can pair this sensor with 3300 XL 50 mm probes and the 3500 Monitoring System for complete vibration protection.

Installation Practices and Operational Benefits

Installing this Proximitor requires securing the DIN-rail bracket and connecting the probe and power cables per the terminal block layout. The front panel LED indicates proper power supply and probe gap status for quick diagnostics. Routine checks of the terminal screw torque will maintain reliable electrical connections over time. This sensor requires no periodic recalibration, though users should verify output using a calibrated target simulator annually. The extended range capability suits large turbines, generators, and thrust bearing monitoring where greater probe standoff is necessary.