Bently Nevada 330881-16-00-307-06-02 Proximity Transducer – PROXPAC XL

Bently Nevada 330881-16-00-307-06-02: Eddy-Current Proximity Transducer for Continuous Shaft Monitoring in Rotating Machinery

The Bently Nevada 330881-16-00-307-06-02 is a self-contained PROXPAC XL proximity transducer assembly integrating an 8 mm eddy-current probe, a factory-matched extension cable of 3.07 m, and a dedicated Proximitor® driver into a single calibrated system. Within a machinery protection control loop, this transducer occupies the signal-acquisition layer: it converts the physical gap between probe tip and rotating shaft surface into a proportional DC voltage, which is then conditioned and evaluated by the upstream monitor module (e.g., Bently Nevada 3500/40M or 3300 XL rack). The assembly is calibrated as a matched set — probe, cable, and driver share a common scale factor of 7.87 V/mm (200 mV/mil) — eliminating field calibration variables that arise when components are mixed across part numbers.

In a typical API 670-compliant turbomachinery protection system, this transducer feeds radial vibration data to the monitor at update rates exceeding 10,000 Hz, enabling the monitor to execute alarm and trip logic within deterministic scan cycles. The DC-coupled output (–1 to –17 VDC across the linear gap range of 0.25–2.54 mm) carries both the AC vibration component and the DC gap (position) component simultaneously, allowing a single transducer to serve dual functions: dynamic vibration measurement and static shaft centerline position tracking.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The PROXPAC XL architecture departs from discrete three-component probe systems by co-engineering the probe, extension cable, and Proximitor® driver as a matched impedance network. The eddy-current probe generates a high-frequency oscillating magnetic field (typically 1.0–1.5 MHz carrier frequency) through its internal LC tank circuit. When a conductive target enters the field, eddy currents induced in the target surface load the tank circuit, shifting its resonant impedance. The Proximitor® driver — a demodulator/oscillator circuit — detects this impedance shift and outputs a linearized DC voltage proportional to gap distance.

The 3.07 m extension cable in this assembly is not a generic coaxial run. Its characteristic impedance is matched to the probe’s LC network within tight tolerances, ensuring that the total cable capacitance does not detune the oscillator frequency beyond the calibrated range. Mismatched cables — even of identical physical length — introduce scale factor errors of 2–5%, which in a protection system translates directly to false alarm thresholds. The factory-matched set eliminates this variable entirely.

EMC performance is achieved through a dual-layer shielding architecture: an inner foil shield provides high-frequency RFI attenuation, while an outer braided shield handles lower-frequency magnetic field coupling common in motor drive environments. The driver housing is constructed from die-cast aluminum with conductive gasket sealing, providing a continuous Faraday enclosure. In installations adjacent to variable-frequency drives (VFDs) operating at switching frequencies of 4–16 kHz, this shielding architecture maintains signal-to-noise ratios sufficient for 0.1 mil (2.54 µm) measurement resolution.

The probe tip assembly uses a ceramic-filled epoxy potting compound rated to 121°C, isolating the coil winding from mechanical stress induced by thermal cycling. This construction prevents the micro-cracking failures observed in earlier-generation probes when subjected to repeated thermal excursions between ambient and bearing-pedestal temperatures of 80–100°C.

System Integration Benefits

• Matched-Set Calibration Eliminates Field Trimming: The probe, cable, and driver are calibrated together at the factory. Scale factor deviation across the matched set is held to ±0.5%, removing the need for field potentiometer adjustment and reducing commissioning time by 30–45 minutes per measurement point.
• Dual-Function Output — Vibration and Position on One Channel: The DC-coupled output simultaneously carries the AC vibration signal (filtered above 1 Hz) and the DC gap voltage, allowing the monitor to compute both dynamic displacement amplitude and static shaft centerline position from a single transducer channel without additional hardware.
• Deterministic Monitor Scan Compatibility: The flat frequency response to 10,000 Hz ensures that the transducer does not introduce phase lag or amplitude roll-off within the monitor’s sampling bandwidth, preserving the timing accuracy required for synchronous vibration analysis (1X, 2X, sub-synchronous components).
• Direct Compatibility with 3500 Series Monitors: The –24 VDC supply and voltage output interface directly with Bently Nevada 3500/40M, 3500/42M, and 3300 XL monitor input cards without signal conditioning adapters, reducing BOM complexity and potential failure points.
• API 670 Alarm and Trip Logic Support: The output range (–1 to –17 VDC) maps directly to the monitor’s configurable alarm setpoints. The linear gap range of 0.25–2.54 mm covers the full shaft displacement envelope specified in API 670 Table 1 for machines up to 3,000 rpm.
• Diagnostic Transparency via Gap Voltage Monitoring: Continuous DC gap voltage monitoring by the upstream monitor provides real-time shaft centerline position data, enabling operators to detect bearing wear, thermal bow, and misalignment trends before vibration amplitude alarms activate — extending planned maintenance intervals.
• Hazardous Area Deployment Readiness: The assembly’s CE marking and ATEX-compatible design (consult specific zone ratings in the datasheet) allows deployment in Zone 2 classified areas common in offshore platforms and petrochemical units without additional barrier hardware in standard configurations.
• Reduced Spare Parts Inventory: Because the PROXPAC XL is a single-part-number assembly covering probe, cable, and driver, maintenance teams stock one SKU instead of three separate components. This simplifies procurement, reduces storage requirements, and eliminates the risk of assembling mismatched components during emergency replacements.

Quality Assurance & Global Logistics

Every Bently Nevada 330881-16-00-307-06-02 unit supplied through siemensplc.com is sourced from verified supply channels with full manufacturer traceability. Prior to dispatch from our Xiamen, China facility, each unit undergoes a structured incoming inspection protocol:

• Electrical Verification: Supply current draw, output voltage at reference gap (1.0 mm nominal), and scale factor linearity across three gap points are measured and recorded against the factory calibration certificate.
• Mechanical Inspection: Probe tip condition, connector pin integrity, cable jacket continuity, and shield resistance (<5 Ω end-to-end) are verified.
• Documentation Package: Each shipment includes the original manufacturer calibration certificate, a certificate of conformance, packing list, and — upon request — a third-party inspection report.
• 12-Month Warranty: All units carry a 12-month warranty against manufacturing defects from the date of shipment, covering electrical performance and mechanical integrity under normal operating conditions.

Logistics from Xiamen are structured for industrial procurement timelines. In-stock units are dispatched within 1–2 business days via DHL Express, FedEx International Priority, or UPS Worldwide Expedited, with typical transit times of 3–5 business days to Europe, North America, and Southeast Asia. Export documentation — including commercial invoice, packing list, Certificate of Origin (Form E for ASEAN preferential tariff), and HS Code 9031.80 classification — is prepared as standard. For projects requiring consolidated shipments or freight forwarding coordination, our logistics team provides full support.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.