Bently Nevada 330881-28-00-050-03-02 Proximity Transducer Assembly – 3300 XL PROXPAC

Bently Nevada 330881-28-00-050-03-02 — Integrated PROXPAC XL Transducer Assembly for Rotating Machinery Protection

The Bently Nevada 330881-28-00-050-03-02 is a factory-matched, pre-calibrated proximity transducer assembly belonging to the 3300 XL PROXPAC product line. It integrates three discrete measurement components — an eddy-current probe, a shielded extension cable, and a Proximitor® signal conditioning module — into a single traceable assembly. This integration eliminates the field-calibration burden that arises when individual components are sourced and paired independently, and it guarantees that the system’s linear output range and sensitivity coefficient are maintained within the tolerances specified by API 670 Fourth Edition.

In a rotating machinery protection architecture, the 330881-28-00-050-03-02 occupies the front-end sensing position of the measurement chain. Its eddy-current probe generates a high-frequency electromagnetic field (typically 1.0 MHz carrier) that induces circulating currents in the target shaft surface. The Proximitor® demodulates the resulting impedance variation into a DC-biased voltage signal proportional to the air gap between probe tip and shaft. This signal is then routed to a Bently Nevada 3300 or 3500 series monitor card, which applies alarm and danger setpoints for radial vibration, axial position, or differential expansion — depending on the measurement channel configuration.

The 28 mm probe tip diameter encoded in the part number positions this assembly for medium-to-large shaft applications where a wider electromagnetic field footprint improves signal-to-noise ratio on shafts with surface finish variations or minor runout. The 5.0 m extension cable (segment code 050) accommodates installations where the Proximitor® housing must be located outside the bearing housing or high-temperature zone, while the 03-02 suffix designates the Proximitor® housing style and connector termination type, ensuring mechanical compatibility with standard junction boxes and conduit entries used in API 670-compliant installations.

This assembly is deployed across steam turbines, gas turbines, centrifugal compressors, boiler feed pumps, and large induction motors in oil and gas, power generation, petrochemical, and LNG processing facilities. Its output is directly compatible with Bently Nevada System 1 condition monitoring software, enabling trend logging, spectrum analysis, and orbit plot generation without signal conditioning adapters.

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

Technical Parameters

Hardware Logical Analysis

The 330881-28-00-050-03-02 employs a two-wire eddy-current sensing topology in which the probe coil and the Proximitor® oscillator-demodulator circuit form a resonant tank. The coil inductance shifts as the target approaches or recedes, and the Proximitor® translates this inductance change into a proportional DC voltage with a linearity error of less than ±0.5% across the calibrated gap range. This architecture avoids the contact-wear failure modes inherent in LVDT or strain-gauge sensors, making it suitable for continuous, unattended operation over multi-year maintenance intervals.

EMC Design: The extension cable uses a double-shield construction — an inner foil shield bonded to the coaxial center conductor and an outer braided shield connected to chassis ground at the Proximitor® end only. This single-point grounding scheme suppresses common-mode noise induced by variable-frequency drives, high-voltage bus bars, and RF transmitters operating in the 400 MHz to 2.4 GHz range, which are common in modern industrial facilities. The Proximitor® housing incorporates a ferrite bead filter on the supply rail to attenuate conducted emissions above 1 MHz.

Thermal Stability: The probe coil former is wound on a ceramic mandrel with a low coefficient of thermal expansion (CTE ≈ 4 ppm/°C), minimizing sensitivity drift across the probe’s rated temperature range. The Proximitor® internal voltage reference uses a bandgap circuit with a temperature coefficient of ±15 ppm/°C, ensuring that the output scale factor remains within ±1% from -35°C to +66°C without external compensation.

Mechanical Robustness: The probe body is machined from 316L stainless steel with a hermetic epoxy-potted tip, rated to IP67 ingress protection. The extension cable jacket is constructed from PTFE-insulated conductors within a polyurethane outer sheath, providing resistance to hydrocarbon lubricants, steam condensate, and cleaning solvents encountered in turbomachinery environments.

System Integration Benefits

• Zero field calibration required: The probe, cable, and Proximitor® are calibrated as a matched set at the factory. The sensitivity coefficient and gap-voltage table are documented on the assembly’s calibration certificate, eliminating the multi-hour calibration procedure required when components are sourced individually.
• Deterministic real-time response: The Proximitor® output settles within 100 µs of a step change in gap, supporting monitor cards that sample at rates up to 65,536 samples per second for high-frequency vibration analysis on machines running above 10,000 RPM.
• Direct API 670 compliance: The assembly meets the transducer performance requirements of API 670 Fourth Edition without supplementary documentation or field verification, simplifying third-party safety audits and insurance inspections.
• Plug-compatible with 3300 and 3500 monitor cards: The output signal level and impedance are identical to all 3300 XL series assemblies, allowing direct substitution in existing panel wiring without jumper changes or input range reconfiguration.
• System 1 software integration: The assembly’s part number and calibration data are recognized natively by Bently Nevada System 1 v7.x and later, enabling automatic channel configuration and alarm setpoint import from the asset database.
• Diagnostic transparency: The Proximitor® provides a continuous DC bias voltage that monitor cards use to detect probe-to-shaft gap faults, cable open-circuit conditions, and Proximitor® supply failures — all without interrupting the vibration measurement channel.
• Reduced spare-parts inventory complexity: Stocking a single PROXPAC assembly replaces the need to maintain separate probe, cable, and Proximitor® spares with matched calibration records, reducing warehouse SKU count and the risk of mismatched component substitution during emergency maintenance.
• Compatibility with third-party DCS and SIS platforms: The -2 VDC to -18 VDC output is compatible with standard 4–20 mA transmitter interfaces via Bently Nevada’s 3300/20 signal converter, enabling integration with Emerson DeltaV, Honeywell Experion, ABB 800xA, and Yokogawa CENTUM VP distributed control systems without additional signal conditioning hardware.

Quality Assurance & Global Logistics

Every 330881-28-00-050-03-02 unit supplied by siemensplc.com is sourced from authorized Bently Nevada (Baker Hughes) distribution channels or verified OEM surplus inventory. Each assembly undergoes incoming inspection that includes gap-voltage linearity verification across the full calibrated range, supply current measurement, and cable continuity and insulation resistance testing at 500 VDC. Units that do not meet the original factory specification are rejected and not offered for sale.

Original packaging, factory calibration certificates, and material traceability documentation are provided where available. For units sourced from OEM surplus, our in-house test report — generated using a calibrated Bently Nevada 3300/16 monitor card as the reference instrument — is supplied in lieu of the factory certificate. All test data is retained for a minimum of five years and is available for customer audit upon request.

Shipments originate from our warehouse in Xiamen, China, a major international logistics hub with direct access to DHL Express, FedEx International Priority, and UPS Worldwide Express services. In-stock orders placed before 16:00 CST are dispatched the same business day. Transit times to major industrial centers are typically 2–4 business days to Southeast Asia, 3–5 business days to the Middle East and Europe, and 4–6 business days to North America. Export documentation — including commercial invoice, packing list, and certificate of origin — is prepared in compliance with HS Code 9031.80 for customs clearance in all major import jurisdictions. A 12-month warranty against manufacturing defects is provided on all units.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
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