Bently Nevada 330104-00-25-10-01-CN Proximity Transducer System – 3300 XL Series

Bently Nevada 330104-00-25-10-01-CN: 25mm Eddy-Current Proximity Transducer System for Critical Rotating Machinery Protection

The 330104-00-25-10-01-CN is a factory-matched, three-component eddy-current proximity transducer system from Bently Nevada’s 3300 XL Series — the most widely deployed non-contact shaft measurement platform in turbomachinery protection. This assembly integrates a 25 mm diameter probe, a 1.0-meter armored extension cable, and a dedicated proximitor/oscillator module, all calibrated as a matched set at the factory. The result is a measurement chain with traceable sensitivity and zero field-matching ambiguity, which is the primary failure mode in mixed-lot transducer replacements.

In rotating machinery protection, the proximity transducer is the first link in the signal chain. Its accuracy, bandwidth, and mechanical integrity determine whether a protection system can distinguish a genuine shaft displacement event from electrical noise — and whether it can do so fast enough to trigger a trip before bearing damage becomes irreversible. The 330104-00-25-10-01-CN is engineered to meet that requirement under API 670 machinery protection standards, making it the reference choice for steam turbines, gas turbines, centrifugal compressors, and large pump trains operating in power generation, oil & gas, and petrochemical facilities.

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Technical Parameters

Hardware Logical Analysis

The 330104-00-25-10-01-CN operates on the eddy-current induction principle. The proximitor drives a high-frequency oscillator signal — typically in the 1–2 MHz range — through the coaxial cable to the probe tip coil. When a conductive target enters the probe’s electromagnetic field, eddy currents are induced on the target surface. These currents load the oscillator circuit, reducing its amplitude in proportion to the gap distance between probe tip and target. The proximitor demodulates this amplitude-modulated RF signal into a DC-proportional voltage output (–1 to –21 VDC), where the DC component represents average gap (position) and the AC component represents dynamic shaft displacement (vibration).

25 mm Probe Geometry and Field Depth: The 25 mm tip diameter produces a broader electromagnetic field footprint compared to 8 mm or 11 mm variants. This geometry extends the usable linear range to 2.54 mm (100 mil), which is critical for axial position and differential expansion measurements where shaft travel distances exceed the range of smaller probes. The wider field also reduces sensitivity to minor surface irregularities on the target, improving signal-to-noise ratio in applications with shaft runout or surface finish variation.

Factory-Matched Calibration Chain: The sensitivity specification of 7.87 V/mm is only valid when the probe, extension cable, and proximitor are used as the matched set defined by the part number. The extension cable’s electrical length and impedance characteristics are factored into the proximitor’s oscillator tuning at the factory. Substituting a cable of different length or construction — even within the same product family — shifts the resonant frequency of the measurement circuit and introduces a sensitivity error that cannot be corrected by field adjustment. This is why the part number encodes cable length (1.0 m in this case) as a fixed parameter.

EMC Design and Signal Integrity: The stainless steel armored braid on the extension cable serves dual functions: mechanical protection against abrasion and vibration fatigue, and electromagnetic shielding of the coaxial signal conductor. In machine environments with variable-frequency drives, high-current bus bars, and switching power supplies, radiated EMI can couple into unshielded signal cables and introduce noise floors that mask low-amplitude vibration signals. The armored coaxial construction maintains shield continuity from probe body to proximitor housing, providing a low-impedance return path that suppresses common-mode interference without requiring additional conduit or shielding measures.

Output Signal Architecture and Built-in Fault Detection: The –1 to –21 VDC output range is intentionally asymmetric. The –1 VDC floor (probe too close to target or open circuit) and –21 VDC ceiling (probe too far from target or cable fault) serve as built-in diagnostic indicators. Monitor cards in the Bently Nevada 3500 series interpret voltages outside the –2 to –18 VDC operating window as transducer fault conditions, triggering a not-OK relay output without requiring a separate fault detection circuit. This architecture reduces the component count in the protection system and eliminates a class of single-point failures where a faulty transducer could produce a plausible but incorrect measurement.

System Integration Benefits

• Direct rack compatibility with 3500 series monitors: The output signal specification is electrically identical to the input requirements of Bently Nevada 3500/40M, 3500/42M, and 3500/45 monitor cards. No signal conditioning, impedance matching, or adapter modules are required between the proximitor output and the monitor card terminal block.
• Deterministic trip response: The DC-coupled output path from proximitor to monitor card eliminates the phase lag introduced by AC-coupled measurement chains. For overspeed and high-vibration trip functions, this means the monitor card receives a real-time representation of shaft position with no filtering delay in the DC signal path — critical for trip response times in the 1–20 ms range required by API 670.
• Dual-use measurement (vibration + position): A single 330104-00-25-10-01-CN installation simultaneously provides the AC vibration signal (dynamic shaft displacement) and the DC gap signal (average shaft position or axial location). This eliminates the need for separate vibration and position transducers on the same measurement plane, reducing installation hardware and cable routing complexity.
• System 1 software integration: The output signal is natively compatible with Bently Nevada System 1 Evolution condition monitoring software. Trend data, alarm setpoints, and transducer health status are accessible through the software’s asset management interface without custom signal mapping or driver configuration.
• Diagnostic transparency via not-OK logic: The transducer’s built-in fault detection propagates directly to the monitor card’s not-OK relay, which can be wired to the plant DCS or safety system. Maintenance teams receive a discrete fault signal without polling the monitor card or interpreting analog values — reducing diagnostic time during plant upsets.
• Consistent sensitivity across replacement cycles: Because sensitivity is factory-calibrated for the matched set, replacement of a failed transducer system with a new 330104-00-25-10-01-CN restores the original calibration without field recalibration. This is particularly valuable in facilities operating under IEC 61511 functional safety requirements, where calibration records must be maintained for each safety instrumented function.
• Wide bandwidth for advanced diagnostics: The DC–10,000 Hz frequency response captures sub-synchronous instability (oil whirl, surge precursors), synchronous 1X and 2X components, and high-frequency structural resonances within a single measurement channel. This bandwidth supports both protection (trip on high vibration) and condition monitoring (trend analysis, spectrum comparison) from the same transducer output.
• Reduced installation risk on replacement projects: The CN connector configuration and 1.0 m cable length are encoded in the part number, ensuring that a replacement order matches the mechanical and electrical configuration of the original installation. This eliminates the most common procurement error in transducer replacement projects — ordering a probe with the correct tip diameter but incorrect cable length or connector type.

Quality Assurance & Global Logistics

Every unit of the 330104-00-25-10-01-CN supplied through siemensplc.com is sourced from verified, traceable supply channels. Incoming inspection covers label authenticity, connector mechanical integrity, cable continuity, and armored braid condition. Units with any indication of field use, connector damage, or label inconsistency are rejected at intake and not offered for sale. Original manufacturer documentation — including datasheet revision, calibration certificate where available, and country of origin declaration — is provided with each shipment.

Shipments originate from our Xiamen, China operations center, which holds active export registration with Xiamen Customs. All Bently Nevada components are classified under the correct HS tariff codes, and export documentation (commercial invoice, packing list, certificate of origin) is prepared to the import requirements of the destination country. This eliminates customs clearance delays that frequently affect industrial component shipments from suppliers without formal export compliance procedures.

Logistics partners include DHL Express, FedEx International Priority, and UPS Worldwide Express. For most destinations in North America, Europe, Southeast Asia, and the Middle East, transit time is 3–5 business days from dispatch. For urgent plant shutdown requirements, same-day dispatch is available on confirmed in-stock units — contact us via WhatsApp for real-time stock confirmation before placing an order.

A 12-month operational warranty covers manufacturing defects and factory calibration integrity. Warranty claims are processed with a replacement-first policy: a replacement unit is dispatched upon receipt of the failed unit and completion of incoming inspection, minimizing the time the customer’s machine train operates without a spare.

Contact Information

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