Bently Nevada 10026-02-12-05-02 Proximity Probe Extension Cable – 3300/3500 Series

Bently Nevada 10026-02-12-05-02 — Impedance-Matched Coaxial Extension Cable for API 670 Eddy-Current Probe Loops

The 10026-02-12-05-02 is a factory-specified coaxial extension cable manufactured by Bently Nevada (a Baker Hughes company) for use within 3300 Series and 3500 Series eddy-current proximity probe systems. In an eddy-current displacement measurement loop, the extension cable is not a passive interconnect — it is an active electrical element whose distributed capacitance, characteristic impedance, and conductor resistance are integral to the oscillator circuit housed inside the proximitor driver. Bently Nevada specifies the 10026-02-12-05-02 to defined electrical tolerances so that the complete three-component assembly — probe, extension cable, proximitor — operates on the factory-calibrated gap voltage curve without field adjustment. Any deviation in cable capacitance-per-unit-length shifts the oscillator’s operating point, introducing a systematic scale-factor error that the monitor’s internal diagnostics cannot detect, because the monitor measures output voltage, not cable impedance.

This part number is widely deployed across gas turbine trains, steam turbine-generator sets, centrifugal compressors, and large motor-driven pump trains in power generation, LNG, refining, and petrochemical facilities. Its consistent availability in the global aftermarket makes it a practical choice for both scheduled maintenance kits and unplanned emergency replacements. siemensplc.com maintains verified sourcing channels across multiple supply regions, enabling rapid fulfillment independent of OEM factory lead times.

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

Technical Parameters

Hardware Logical Analysis

The eddy-current proximity measurement principle relies on a resonant LC oscillator within the proximitor. The probe coil, energized at a fixed carrier frequency, generates an alternating magnetic field. When a conductive target surface enters this field, eddy currents are induced in the target, loading the probe coil and reducing the oscillator’s amplitude. The proximitor converts this amplitude change into a DC gap voltage output — typically –24 VDC at maximum gap, scaling linearly toward 0 VDC as the target approaches. The extension cable’s distributed capacitance appears in parallel with the probe coil from the oscillator’s perspective. If this capacitance deviates from the OEM-specified value, the oscillator’s resonant frequency shifts, altering the sensitivity (mV/mil or mV/µm) of the entire assembly. The 10026-02-12-05-02 is manufactured to a defined capacitance-per-unit-length specification, ensuring that the total cable capacitance — probe integral cable plus extension cable — remains within the oscillator’s linear operating window.

From an electromagnetic compatibility standpoint, the coaxial construction provides continuous 360° electrostatic shielding along the full cable length. In turbine hall environments, the cable routinely runs parallel to high-current motor feeders, variable-frequency drive output cables, and bus bars carrying hundreds of amperes. These conductors generate strong alternating magnetic fields at fundamental and harmonic frequencies. The coaxial shield intercepts capacitively coupled interference before it reaches the center conductor. The single-point grounding scheme — shield terminated at the proximitor chassis, floating at the probe end — prevents the formation of a ground loop between the probe mounting structure and the control room ground reference. A ground loop would allow power-frequency currents to flow through the shield, inducing a common-mode voltage on the center conductor that the proximitor’s differential input stage cannot fully reject, resulting in a 50/60 Hz ripple superimposed on the gap voltage output.

Connector contact resistance is the primary long-term degradation mechanism for extension cables in service. The OEM connector plating specification on the 10026-02-12-05-02 uses materials selected for stable contact resistance over multi-year service intervals in atmospheres containing hydrogen sulfide, ammonia, and hydrocarbon vapors — conditions common in refinery and gas processing environments. Intermittent contact resistance — caused by connector oxidation or mechanical fretting — produces transient open-circuit conditions on the center conductor. The proximitor interprets an open-circuit probe input as a maximum-gap condition, generating a voltage spike toward –24 VDC. Depending on the monitor’s alert and danger setpoint configuration, this transient can trigger a false machinery trip, with direct operational cost implications in continuous-process plants where an unplanned shutdown of a critical compressor train may cost tens of thousands of dollars per hour.

System Integration Benefits

• Calibration curve preservation: The OEM-specified cable capacitance keeps the probe-cable-proximitor assembly on the factory calibration curve, maintaining displacement measurement accuracy within ±1% of full scale across the rated temperature range — no field recalibration required after a like-for-like replacement.
• Zero setpoint adjustment on swap: Because the electrical characteristics are matched to the original assembly, gap voltage zero references and alert/danger setpoints remain valid after cable replacement, reducing maintenance window duration and eliminating the risk of setpoint entry errors during re-commissioning.
• Deterministic signal propagation: The cable’s electrical length is consistent with OEM design intent, ensuring signal propagation delay remains within the 3500 monitor’s sampling window — relevant for high-speed machinery where shaft orbital events occur at frequencies above 100 Hz and sub-millisecond timing accuracy is required for accurate Keyphasor-referenced vector measurements.
• Monitor self-diagnostic compatibility: Bently Nevada 3500 Series monitors perform continuous loop impedance verification. An extension cable with correct impedance characteristics allows these diagnostics to operate as designed, providing early detection of cable degradation — broken shield, center conductor damage, or connector deterioration — before a measurement failure occurs.
• Intrinsic safety boundary compliance: When the 10026-02-12-05-02 is used within a certified IS assembly incorporating ATEX/IECEx-rated probes and approved Zener barriers or galvanic isolators, the cable’s capacitance remains within the IS certification’s maximum cable capacitance limit. Non-OEM cables with higher capacitance-per-unit-length may exceed this limit, invalidating the IS certification and creating a regulatory compliance exposure in Zone 1 or Zone 2 classified areas.
• False trip probability reduction: Stable connector contact resistance and correct single-point shield grounding eliminate the two primary sources of transient signal artifacts — connector intermittency and shield ground loop currents — that generate spurious gap voltage excursions capable of triggering unwarranted machinery trips.
• Cross-platform spare parts consolidation: The 10026-02-12-05-02 is electrically compatible with both the legacy 3300 Series and the current 3500 Series monitoring racks, allowing a single part number to serve multiple machine trains within a facility and simplifying spare parts inventory management.
• Documentation alignment: Specifying the OEM part number maintains alignment with Bently Nevada system documentation, P&ID cable schedules, and maintenance management system (CMMS) records, reducing the administrative burden of non-conformance documentation that arises when non-OEM substitutes are used.

Quality Assurance & Global Logistics

Each unit of the 10026-02-12-05-02 dispatched from siemensplc.com undergoes a structured pre-shipment inspection covering connector body mechanical integrity, cable jacket condition, OEM label and part number verification, and — where test equipment permits — center conductor continuity and shield resistance measurement. Sourcing chain-of-custody documentation is retained per batch and provided to customers upon request, supporting traceability requirements under ISO 9001-aligned maintenance programs.

All shipments originate from Xiamen, China. Xiamen Gaoqi International Airport operates direct cargo routes to major freight hubs in Europe, the Middle East, Southeast Asia, and North America. Xiamen Port, ranked among China’s top-ten container ports by annual throughput, provides sea freight options for volume orders. Standard express air freight via DHL, FedEx, and UPS achieves door-to-door transit times of 3–7 business days to most industrial destinations globally. Export documentation — commercial invoice, packing list, certificate of conformance, and country of origin declaration — is prepared in compliance with Xiamen Customs requirements, ensuring efficient clearance at destination ports. Payment is accepted in USD, EUR, CNY, and other currencies by arrangement; T/T and L/C terms are supported for B2B transactions.

Contact Information

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Location: Xiamen, China
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