Bently Nevada 330850-00-03 | 3300 XL 25mm Proximitor Sensor

Ultra-large rotating machinery such as heavy industrial steam turbines, large-scale centrifugal compressors and reciprocating units features extremely large shaft runout, axial thrust displacement and complex vibration fluctuation characteristics. Conventional 8mm and 11mm proximitor sensors have limited linear stroke and cannot capture oversized displacement signals, resulting in monitoring failure and protection misoperation. The Bently Nevada 330850-00-03 is a professional signal conditioning unit exclusively developed for the 3300 XL 25mm super-large range eddy current probe system. Different from small and medium-size proximitor models, this device supports ultra-wide linear signal conversion, adapts to 3-meter short-distance compact wiring layout, and is dedicated to heavy-duty industrial core equipment condition monitoring. It stably converts large-stroke shaft displacement and vibration signals, serving as the core signal processing component for high-load TSI machinery protection systems.

Part Number Code Practical Field Interpretation

The suffix coding rules of the 330850 series are independently defined for 25mm ultra-large probe systems, covering system calibration length and application grade, which helps field engineering and maintenance personnel quickly complete model matching and wiring verification:

Core Electrical & Calibration Technical Parameters

Full Part Number：330850-00-03

Product Category：25mm ultra-large range eddy current proximitor signal conditioner

Matched Sensing Device：Full series 3300 XL 25mm proximity probes and supporting dedicated extension cables

Professional Calibration Sensitivity：0.787 V/mm (20 mV/mil), exclusive low-sensitivity high-range calibration for 25mm super-large probe system

Ultra-Wide Linear Monitoring Range：0mm to 12.7mm (0–500mils), covering ultra-large shaft swing and axial thrust displacement of heavy-duty main units

Optimal Installation Gap：6.35mm (250mils), the most stable linear working point for long-term continuous monitoring

Effective Frequency Response：0Hz–5kHz, fully adapting to low-frequency large displacement and medium-frequency vibration fault characteristics of heavy rotating machinery

Power Supply Requirements：-17.5Vdc ~ -26Vdc standard industrial DC power supply, stable startup without voltage drift

Operating Temperature Scope：-40℃ to +85℃, adapting to complex temperature changes in heavy industrial equipment rooms

Signal Output Form：High-stability linear DC voltage output, real-time synchronous response to large-stroke gap changes between probe and rotor surface

Anti-Interference Performance：Built-in EMI shielding circuit, resisting on-site high-power equipment electromagnetic crosstalk and signal noise

Complete System Matching Rules

The 330850-00-03 ultra-large range proximitor has exclusive matching standards, which cannot be replaced by 8mm or 11mm conventional models arbitrarily, so as to avoid linear range mismatch and monitoring data failure:

• Probe Matching：Strictly adapted to 330851 series 25mm super-large diameter proximity probes, supporting all standard thread and structural configurations

• Cable Length Limit：The total length of probe integrated cable and supporting extension cable must not exceed 3 meters, with built-in short-distance signal optimization circuit to ensure zero attenuation transmission

• Rear-End Module Adaptation：Seamlessly compatible with Bently Nevada 3500/42 vibration monitoring modules and 3500/45 position monitoring modules, realizing data collection, trend analysis and safety interlock output

• System Calibration Features：Factory unified one-time calibration, no need for on-site secondary debugging, plug-and-play installation improves commissioning efficiency

Unique On-Site Application Advantages

Different from medium and small range proximitors, the core advantage of 330850-00-03 lies in its ultra-large linear stroke capability. Heavy-duty main units often produce shaft displacement exceeding 5mm during startup, load switching and fault states, which far exceeds the monitoring range of 8mm and 11mm sensors, easily causing signal overload and monitoring blind spots. This 25mm dedicated proximitor perfectly solves this industry pain point, stably capturing ultra-large displacement changes of rotating shafts.

The 3-meter short-system calibration design is tailored for compact centralized cabinet layout of heavy industrial equipment rooms. The optimized internal circuit structure ensures ultra-stable signal transmission in short-distance wiring, without jitter or distortion. The industrial-grade anti-interference and anti-temperature-drift design enables long-term 7×24-hour stable operation, effectively reducing false alarms and equipment maintenance frequency of heavy unit protection systems.

Typical Industrial Deployment Scenarios

This 25mm ultra-large range proximitor is exclusively used for condition monitoring of heavy-load core industrial equipment. In thermal power industry, it is widely deployed for ultra-large steam turbine main shaft axial thrust displacement, large swing vibration and generator rotor operation monitoring, adapting to super-large displacement working characteristics of high-power units.

In petrochemical and heavy chemical fields, it serves large reciprocating compressors, ultra-large centrifugal compressors and turbo main units, accurately monitoring oversized shaft runout and bearing displacement. It is the preferred replacement accessory for renovation of old heavy-unit TSI systems, with high compatibility, no need to modify original system layout and parameters, and low renovation cost.