Bently Nevada 330881-28-05-035-01-02 Proximity Transducer – PROXPAC XL

Bently Nevada 330881-28-05-035-01-02 PROXPAC XL — Integrated Eddy-Current Transducer Assembly for Rotating Machinery Protection

The Bently Nevada 330881-28-05-035-01-02 is a factory-matched, integrated proximity transducer assembly belonging to the PROXPAC XL product family. It combines an 8 mm eddy-current probe, a 28-inch armored probe cable, a 5-meter extension cable, and a proximitor driver into a single calibrated loop. This architecture eliminates the sensitivity tolerance stack-up that occurs when mixing independently sourced probe, extension, and driver components — a critical requirement in API 670 5th Edition machinery protection systems where loop sensitivity must be verified as a complete assembly rather than as individual elements.

The assembly operates on a –24 VDC supply and delivers a linear output voltage of –1 to –21 VDC across a measurement gap range of 0.25 to 2.54 mm (10 to 100 mil), with a nominal sensitivity of 7.87 V/mm (200 mV/mil). The flat frequency response from DC to 10,000 Hz (–3 dB) makes this transducer suitable for both static position measurement and dynamic vibration analysis up to the 10th harmonic of a 1,000 RPM machine — covering the full diagnostic bandwidth required for steam turbines, gas turbines, centrifugal compressors, and large rotating equipment in power generation and hydrocarbon processing.

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

Technical Parameters

Hardware Logical Analysis

The eddy-current measurement principle in the 330881-28-05-035-01-02 relies on a high-frequency oscillator circuit embedded in the proximitor driver, which drives an alternating magnetic field through the probe coil at a carrier frequency typically in the range of 1.0 to 1.5 MHz. When a conductive target enters the probe’s electromagnetic field, eddy currents are induced on the target surface, loading the oscillator and reducing its amplitude. The driver demodulates this amplitude change into a DC-proportional output voltage, producing the 200 mV/mil transfer function.

The PROXPAC XL integrated design addresses a fundamental calibration problem in modular eddy-current systems: the cable capacitance between the probe and driver is a direct variable in the oscillator’s resonant tank circuit. Any deviation in cable length or dielectric constant from the factory-calibrated value shifts the resonant frequency and alters the sensitivity. By fixing the probe cable at 28 inches and the extension at 5 metres as a matched set, Bently Nevada eliminates this variable entirely. The result is a factory-guaranteed sensitivity of 200 mV/mil ± 1% across the full linear range — a tolerance that cannot be reliably achieved with field-assembled modular components.

The probe body is constructed with a hermetically sealed ceramic-filled epoxy tip, which provides both mechanical protection and thermal stability. The PTFE-jacketed probe cable maintains consistent dielectric properties from –35 °C to +177 °C, preventing sensitivity drift in high-temperature bearing housing environments. The driver module incorporates internal EMC filtering on both the supply and output lines, attenuating conducted interference from variable-frequency drives, switchgear, and other industrial noise sources that are common in turbine hall environments. The MIL-C-5015 style connector provides a positive locking mechanism rated for repeated mating cycles, maintaining contact resistance below 10 mΩ throughout the service life of the assembly.

System Integration Benefits

• API 670 Loop Validation Without Field Calibration: The assembly ships with factory calibration data traceable to NIST standards. No field sensitivity verification is required prior to commissioning, reducing outage time during turbine overhauls.
• Direct Compatibility with Bently Nevada 3300 XL Monitor Rack: Plug-and-play interface with 3300/16 (radial vibration), 3300/20 (thrust position), and 3300/25 (eccentricity) monitor cards. No signal conditioning adapters required.
• Deterministic Signal Latency: The DC-coupled output path from probe to monitor card introduces no phase shift below 1,000 Hz, preserving the temporal accuracy of 1X and 2X vibration vectors used in rotor dynamic diagnostics.
• Broad Thermal Operating Envelope: Probe rated to +177 °C allows direct installation in bearing housings on HP turbine stages without thermal standoff brackets, simplifying mechanical installation and reducing potential leak paths.
• High Ingress Protection: IP67-rated probe body withstands wash-down, oil mist, and condensation in turbine bearing pedestals and compressor seal areas without signal degradation.
• Reduced Wiring Complexity: Single-assembly construction eliminates the three-connector junction (probe-to-extension, extension-to-driver) present in modular systems, reducing the number of potential high-impedance fault points in the signal path from three to one.
• Bently Nevada System 1 Integration: Output signal is fully compatible with System 1 condition monitoring software for trend logging, alarm management, and rotor dynamic analysis without additional signal scaling.
• Non-Contact Measurement Eliminates Mechanical Wear: Eddy-current sensing imposes zero mechanical load on the rotating shaft, providing indefinite sensor service life independent of machine speed or shaft surface condition, subject only to environmental degradation of the probe body.

Quality Assurance & Global Logistics

Every 330881-28-05-035-01-02 unit dispatched from our Xiamen, China facility undergoes a structured incoming inspection protocol before it is allocated to any order. This includes visual verification against Bently Nevada OEM labeling and cosmetic standards, continuity and insulation resistance measurement on the probe cable and extension, sensitivity verification against the factory calibration record (200 mV/mil ± 5% acceptance criterion), and serialization with a five-year traceability record retained in our quality management system.

Units are sourced exclusively from authorized distribution channels and verified surplus inventories with full chain-of-custody documentation. Each shipment is accompanied by the original factory calibration data sheet and, where available, a third-party calibration certificate. Packaging follows anti-static and mechanical protection standards appropriate for precision instrumentation: individual foam-lined boxes, moisture barrier bags, and outer cartons rated for international air freight handling.

From Xiamen, we dispatch via DHL Express, FedEx International Priority, and UPS Worldwide Expedited, with typical transit times of 3–5 business days to Europe, North America, the Middle East, and Southeast Asia. In-stock units are processed and handed to the carrier within 24 hours of order confirmation. Export documentation — including commercial invoice, packing list, and certificate of origin — is prepared to comply with customs requirements in the destination country. HS Code 9026.80 applies to this product category for most jurisdictions.

All units carry a 12-month warranty from the date of shipment, covering defects in materials and workmanship under normal operating conditions as defined by Bently Nevada’s published installation and maintenance guidelines.

Contact Information

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