Bently Nevada 330878-90-00 is a proximitor sensor belonging to the Bently Nevada 3300 series, a core component for non-contact measurement in industrial automation. Adopting the well-established eddy current measurement principle, it forms a complete sensor system when paired with probes and extension cables of the same series, enabling accurate monitoring of key parameters of rotating machinery such as shaft displacement, vibration, speed and key phase. It provides reliable data support for the safe and stable operation of large rotating equipment including steam turbines, compressors and pumps, and is widely used in heavy industries such as power generation, petroleum and chemical engineering. Compliant with industrial safety standards, it features excellent compatibility and environmental adaptability, making it one of the widely applied classic proximitor products in the Bently brand.
1. Core Product Positioning & Applications
Bently Nevada 330878-90-00 is essentially a proximitor module for the 3300 series eddy current sensor system. As the signal processing core of the entire measurement system, it converts high-frequency electrical signals collected by the probe into standard identifiable voltage signals for transmission to monitors for display, alarm or linkage control. Its core applications focus on non-contact condition monitoring of rotating machinery, specifically:
- Radial shaft vibration measurement
- Axial (thrust) displacement measurement
- Speed detection
- Key phase signal acquisition
Suitable for various large rotating equipment such as oil-film bearing machinery, it provides accurate data support for equipment fault early warning, condition diagnosis and maintenance, ensuring long-term stable operation, reducing downtime risks and maintenance costs.
This product is brand new and original, usually packaged in a box with a 12-month warranty and fast delivery. It is widely supplied as spare parts for replacement or new system construction in industrial automation PLC, DCS and TSI systems, serving as an indispensable supporting component of the Bently 3300 series sensor system.
2. Operating Principle
This proximitor sensor realizes non-contact measurement based on the eddy current effect, consistent with the operating logic of the Bently 3300 series sensor system:A coil carrying a high-frequency signal is wound inside the probe. When the relative position between the probe and the measured metal shaft surface (typically AISI 4140 steel target) changes, eddy currents are induced on the metal surface. The intensity of these eddy currents varies with the gap between the probe and the target, which in turn alters the energy loss of the high-frequency signal within the probe coil.
The Bently Nevada 330878-90-00 proximitor receives the high-frequency signal from the probe, processes it through filtering, amplification and conversion, and finally outputs a voltage signal proportional to the change in the probe-target gap. This signal can be directly connected to the Bently monitoring system or other compatible industrial monitoring devices for real-time equipment condition monitoring and data feedback. The entire measurement process requires no contact with the measured component, causing no interference to equipment operation. Measurement accuracy is not significantly affected by environmental dust, oil and other contaminants, ensuring exceptional stability.
3. Key Technical Specifications (Under Official Standard Conditions)
Specifications are tested under standard conditions: ambient temperature 18–27°C (64–80°F), -24VDC power supply, 10kΩ load, AISI 4140 steel target, probe gap 1.27 mm (50 mils).
Electrical Parameters
- Supply voltage: -24VDC, compliant with industrial standards for stable operation in complex industrial power environments
- Output signal: Voltage signal proportional to gap variation, compatible with signal input requirements of various industrial monitoring systems
Measurement Parameters
- Minimum target size (flat target): 15.2 mm (0.6 in) diameter
- Minimum measured shaft diameter: 50.8 mm (2 in)
- Recommended measured shaft diameter: 76.2 mm (3 in) to ensure measurement accuracy and stability
Cable Parameters
- Typical capacitance of extension cable: 69.9 pF/m (21.3 pF/ft)
- Recommended cable: 3-core shielded triaxial cable
- Maximum field wiring length between proximitor and monitor: 305 meters (1000 ft). For longer wiring or external safety barriers, refer to performance specification 155687 for high-frequency signal attenuation.
Safety & Certification
- Compliant with CSA/NRTL/C safety standards
- Explosion-proof rating: Exia, suitable for Class I, Zone 1 hazardous environments for safe use in flammable and explosive industrial scenarios
Compatibility
- Fully compatible with Bently 3300 series probes and extension cables
- Interchangeable with non-XL 3300 series 5 mm and 8 mm sensor system components, providing excellent backward compatibility for system upgrades and spare part replacement
4. Product Structure & Installation Requirements
Product Structure
Bently Nevada 330878-90-00 features a compact design, supporting both 35 mm standard DIN rail mounting (IEC 60715 compliant) and traditional panel mounting. Its panel mounting holes align with legacy 4-hole 3300 proximitors, enabling replacement and upgrade without modifying mounting positions. Constructed with high-strength materials, it offers superior mechanical stability and corrosion resistance. Optimized internal circuitry delivers strong resistance to radio frequency interference (RFI/EMI), meeting European EMC standards without special shielded conduits or metal enclosures, reducing installation costs and complexity.
Equipped with corrosion-resistant ClickLoc gold-plated copper connectors with mechanical locking, the connectors can be finger-tightened without special tools, effectively preventing loose connections and ensuring stable signal transmission. Connector protectors are optional for extended service life in humid and oily environments.
Installation Requirements
- Installation Environment: The proximitor shall be installed floating (electrically insulated from the unit) in a well-ventilated, low-vibration location with temperature below 65°C, avoiding high temperatures, strong vibration and electromagnetic interference. A dedicated protection box is recommended, with the proximitor floating-mounted on an insulating plate inside the box, which is then fixed to a frame or railing to prevent damage.
- Wiring Requirements: Use 3-core shielded cables with the shield grounded at the control room end only to reduce signal interference. Maintain proper cable bending radius to avoid damage. For wiring exceeding 305 meters, consult official performance specifications to assess signal attenuation and implement corrective measures.
- Installation Steps: For rail mounting, snap the rail clip onto 35 mm DIN rail, align and press the proximitor into the clip, then connect the sensor cable and power supply. Installation is tool-free for rapid deployment and maintenance. Verify secure connections after installation.
5. Product Advantages & Features
- High Reliability: As a genuine Bently product, it undergoes strict factory calibration and quality testing. Featuring mature eddy current measurement technology, it delivers high accuracy and stability for long-term operation in harsh industrial environments. Backed by a 12-month warranty, it reduces maintenance costs and failure risks.
- Strong Compatibility: Fully compatible with Bently 3300 series sensor components, freely combinable with 3300 series probes and extension cables, and interchangeable with legacy non-XL 3300 series parts. No major modifications to existing monitoring systems are required, facilitating system upgrades and spare part replacement to improve versatility and flexibility.
- Easy Installation: Supports rail and panel mounting with tool-free, quick installation and removal. Strong anti-interference performance eliminates the need for additional shielding, reducing installation complexity and cost to adapt to various industrial control cabinet layouts.
- Safety & Compliance: Meets CSA/NRTL/C safety and explosion-proof standards for safe use in hazardous industrial environments including flammable, explosive, high-temperature and dusty conditions. Designed in accordance with API 670 (4th Edition), satisfying stringent heavy industry requirements.
- Convenient Maintenance: Rational structural design with SpringLoc terminal blocks for screw-free wiring, preventing loosening from vibration and ensuring robust connections. Rapid disassembly and replacement in case of failure, with interchangeable same-series components, significantly shortening maintenance downtime and improving operational efficiency.
6. Application Scenarios & Supporting Components
Application Scenarios
Primarily used for non-contact condition monitoring of rotating machinery in industrial fields, especially:
- Steam turbines, generators in power generation
- Compressors, pumps, fans in petrochemical industry
- Rolling mills in metallurgy
It enables real-time monitoring of shaft displacement, vibration, speed and other parameters, providing accurate data for fault early warning and condition diagnosis to ensure safe equipment operation and avoid production interruptions and economic losses from failures.
Supporting Components
As a proximitor, Bently Nevada 330878-90-00 must be paired with the following components to form a complete eddy current sensor system:
- 3300 Series Probes: Recommended 3300 XL 8 mm or 5 mm probes with patented TipLoc technology for secure tip-to-body connection and CableLoc design for withstanding 330 N (75 lbf) tension. FluidLoc cables are optional to prevent oil leakage along the cable.
- 3300 Series Extension Cables: Used with probes to extend the distance between the probe and proximitor. Extended Temperature Range (ETR) extension cables are optional for probe lead or extension cable temperatures exceeding 177°C (350°F), withstanding up to 260°C (500°F).
- Monitoring Systems: Compatible with Bently 3500 series monitoring systems or other industrial monitoring devices for signal display, alarm and data storage/analysis to support equipment maintenance.
- Auxiliary Accessories: Including rail clips, protection boxes and connector protectors for installation assistance and enhanced durability in complex environments.
3005319639