Bently Nevada 330800-16-00-039-03-02 Proximity Transducer Assembly – 3300 XL Series

Bently Nevada 330800-16-00-039-03-02 PROXPAC XL: Eddy-Current Transducer Assembly for Turbomachinery Protection

The Bently Nevada 330800-16-00-039-03-02 is a factory-calibrated PROXPAC XL proximity transducer assembly belonging to the 3300 XL Series platform. It integrates a 16 mm eddy-current probe, a 1000 mm (39 in) armored extension cable, and a dedicated proximitor/oscillator into a single matched assembly. This configuration eliminates the measurement uncertainty introduced by field-assembled component combinations and is the preferred procurement format for reliability engineers operating under API 670 machinery protection mandates.

The assembly is engineered for continuous, non-contact shaft displacement measurement on rotating machinery — including steam turbines, gas turbines, centrifugal compressors, and multistage pumps — where shaft radial vibration, axial position, and differential expansion must be monitored with sub-micron resolution and deterministic signal latency. The output scale factor of −3 VDC/mil (−118 mV/µm) is directly compatible with all Bently Nevada 3500 Series monitor cards without signal conditioning adapters.

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

Technical Parameters

Hardware Logical Analysis

The 330800-16-00-039-03-02 operates on the eddy-current induction principle. The proximitor’s internal oscillator generates a high-frequency RF carrier — nominally 1 MHz — which is transmitted through the coaxial extension cable to the probe coil wound at the tip. When a conductive target (shaft) enters the probe’s electromagnetic field, eddy currents are induced on the target surface. These eddy currents extract energy from the oscillator circuit, causing a measurable change in oscillator amplitude and impedance. The demodulator stage within the proximitor converts this amplitude variation into a proportional DC voltage output at −3 VDC/mil.

EMC Design Architecture: The 3300 XL proximitor housing incorporates a fully shielded aluminum enclosure with continuous ground bonding between the probe body, cable shield braid, and proximitor chassis. This three-point shield topology suppresses common-mode noise injection from adjacent power cables and variable-frequency drives (VFDs), which are prevalent in compressor train environments. The coaxial cable geometry maintains a controlled characteristic impedance of 50 Ω across the full 1000 mm run, preventing standing-wave reflections that would introduce measurement nonlinearity at high shaft rotational frequencies.

Thermal Stability: The probe coil is wound on a ceramic bobbin with a low thermal coefficient of expansion. This construction maintains gap sensitivity within ±0.5% across the full −35 °C to +177 °C probe operating range — a critical requirement for steam turbine bearing housings where metal temperatures can exceed 150 °C during sustained load operation. The proximitor’s internal voltage reference is temperature-compensated to hold output offset drift below ±10 mV over its −35 °C to +85 °C range.

Factory Calibration Traceability: Each PROXPAC XL assembly is calibrated as a matched set on a Bently Nevada calibration bench using a precision micrometer-driven target fixture. The calibration data — including scale factor, zero-gap voltage, and linearity deviation — is recorded against the assembly serial number. This eliminates the ±5% scale factor tolerance stack-up that occurs when probe, cable, and proximitor are sourced and assembled independently in the field.

System Integration Benefits

• Direct 3500 Series Compatibility: The −3 VDC/mil output maps directly to the input range of Bently Nevada 3500/40M, 3500/42M, and 3500/45 monitor cards. No signal conditioning, range adapters, or firmware parameter changes are required at the monitor level.
• Deterministic Signal Latency: The DC-coupled output path from probe tip to monitor input introduces no phase shift below 10 kHz, preserving the temporal integrity of vibration waveforms used for orbit plot construction and sub-synchronous instability detection.
• Plug-and-Play Field Replacement: The MIL-C-5015 connector and standardized cable length allow direct swap-out of a failed assembly without re-routing cables or re-terminating field wiring. Mean time to restore (MTTR) is reduced to under 30 minutes for a trained technician.
• Diagnostic Transparency: The proximitor’s OK output relay de-energizes when the probe gap falls outside the linear range (gap too close or too far), providing a discrete fault signal to the 3500 rack’s system OK chain. This enables the monitor to distinguish a genuine vibration alarm from a transducer fault condition.
• Multi-Parameter Measurement: A single assembly can simultaneously provide radial vibration (AC component), average shaft centerline position (DC component), and slow-roll runout data to the monitor — three independent diagnostic parameters from one transducer channel.
• Hazardous Area Deployment: ATEX and FM certifications (suffix-dependent) permit installation in Zone 1/Division 1 classified areas without additional intrinsic safety barriers, simplifying the loop design for offshore and petrochemical applications.
• Reduced Commissioning Risk: Factory-matched calibration eliminates the need for on-site scale factor verification using a calibration fixture — a step that is frequently skipped under schedule pressure and is a known source of protection system errors.
• Long-Term Spare Parts Standardization: The PROXPAC XL format allows maintenance planners to stock a single part number that covers probe, cable, and proximitor as a unit, reducing spare parts inventory complexity and eliminating the risk of stocking mismatched component combinations.

Quality Assurance & Global Logistics

Every Bently Nevada 330800-16-00-039-03-02 unit dispatched from our Xiamen, China facility is sourced through verified industrial distribution channels and undergoes a structured pre-shipment inspection protocol:

• Visual inspection of probe tip, cable jacket integrity, and MIL-C-5015 connector pin condition
• Electrical continuity check across the full coaxial signal path from probe coil to proximitor output terminals
• Insulation resistance measurement between signal conductors and cable shield (minimum 100 MΩ at 500 VDC)
• Output voltage spot-check at a known gap distance to verify scale factor within ±2% of nominal −3 VDC/mil
• Serialization and traceability documentation retained on file; Certificate of Conformance (CoC) provided upon request

Packaging uses anti-static foam-lined cartons with desiccant packs to protect the probe coil and proximitor electronics during transit. Export documentation — including commercial invoice, packing list, and ECCN classification — is prepared for all international shipments. Standard delivery from Xiamen to major industrial hubs: 3–5 business days (DHL/FedEx Express); economy freight options available for non-urgent orders. All shipments are fully insured and tracked from dispatch to delivery confirmation.

Contact Information

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