Product Overview

The Bently Nevada 330104-15-25-10-02-05 is a highly specialized 3300 XL 8 mm Proximity Probe designed for critical machinery protection systems (MPS) and continuous turbomachinery condition monitoring. Operating on non-contacting eddy current principles, this transducer delivers high-precision displacement data to track radial shaft vibration, axial thrust position, and speed/phase reference (Keyphasor) telemetry. It is engineered to monitor high-speed rotor dynamics inside fluid-film bearing housings across a wide range of industrial processing environments.

The 3300 XL 8 mm sensor system offers a dependable linear operating range of 2.0 mm (80 mils). It excels at maintaining an exceptionally flat thermal response across fluctuating internal machinery temperatures, providing excellent repeatability where minor deviations could trip a multi-megawatt asset. By minimizing thermal drift, this sensor helps prevent false trips while ensuring absolute machine protection.

This specific configuration features an English fractional 3/8-24 UNF threaded body with a 1.5-inch unthreaded section, a 2.5-inch overall case length, a 1.0-meter (3.3 feet) integrated unarmored coaxial cable, and a gold-plated miniature coaxial ClickLoc connector. Equipped with the comprehensive 05 Multiple Approvals package, it complies with global intrinsic safety (IS) and non-incendive design rules, making it suitable for deployment across hazardous industrial locations worldwide.

Technical Specifications

Model Configuration Explanation

The model string 330104-15-25-10-02-05 represents a precise selection from the Bently Nevada 3300 XL 8 mm catalog, mapping out the physical parameters required for exact mechanical field drop-ins:

• 330104: The foundational base model number for the 3300 XL 8 mm Proximity Probe configured with an English fractional thread profile (3/8-24 UNF).
• 15: Unthreaded Length Option. Specifies a 1.5-inch unthreaded sleeve behind the probe tip. This design provides clean clearance inside deep mounting blocks or specialized sleeve adaptors.
• 25: Overall Case Length Option. Designates a 2.5-inch total case length, giving the sensor structural body depth to pass through average machinery housing interfaces.
• 10: Total Length Option. Dictates a 1.0-meter (3.3 feet) integrated cable lead, bringing the delicate connection out of direct exposure to the bearing housing core.
• 02: Connector and Cable Type Option. Selects a standard unarmored flexible coaxial cable terminated with a miniature coaxial ClickLoc connector. This configuration provides a tight bend radius and easy routing within dedicated protective field conduits.
• 05: Agency Approval Option. Multiple Approvals certification package, covering international intrinsic safety (IS) and non-incendive rules under ATEX, IECEx, and North American CSA frameworks for Zone 0, Zone 1, Zone 2, and Class I Division 1/2 environments.

Typical Applications

The 330104-15-25-10-02-05 proximity probe is critical for assessing machine health across continuous process industries, particularly where unarmored leads are routed through internal brackets or protective conduit sleeves:

• Radial Shaft Vibration: Installed in dual X-Y orthogonal arrangements on fluid-film (journal) bearings to map shaft dynamic behavior, centerline orbital profiles, and structural instabilities like oil whip or oil whirl.
• Axial Thrust Position: Deployed in dual-redundant or triple-modular redundant (TMR) configurations targeting shaft thrust collars to detect axial drift and prevent rotor-to-stator collisions within steam or gas turbines.
• Keyphasor Phase Reference: Monitors an intentional notch or keyway on the shaft to establish an accurate once-per-revolution phase mark, critical for tracking synchronous phase angles and variable machine RPM.
• Machinery Categories Covered: High-pressure boiler feed pumps, multi-stage centrifugal compressors, gas turbine generators, process air fans, and heavy turbo-expanders within power generation, refining, and chemical processing complexes.

System Compatibility

To satisfy rigorous API 670 operational design parameters, the 330104 proximity probe must be matched with its complementary signal conditioning components to complete the circuit loop:

• Extension Cable Selection: Must be paired with a 3300 XL 8 mm Extension Cable (such as the 330130 series). Because the integrated probe cable length is 1.0 meter, it must be paired with either a 4.0-meter or 8.0-meter extension cable to establish a true 5.0-meter or 9.0-meter total system tuning loop.
• Proximitor Sensor Integration: Connects directly into a matching 3300 XL Proximitor Sensor (Model 330180). The Proximitor supplies the radio frequency (RF) excitation to the probe tip and translates the return eddy current impedance changes into a linear -24 Vdc voltage representation.
• Protection Monitors: Links via terminal blocks directly to the backplane inputs of the Bently Nevada 3500/42M Proximitor Seismic Monitor module, the 3500/25 Keyphasor card, or legacy standalone 3300 vibration controllers.

Mechanical Position & Gapping Guidelines

• Shaft Surface Treatment: Ensure the shaft measurement path is completely free of grinding patterns, score marks, or metallurgic variations. A surface finish of 0.8 micrometers (32 microinches) Ra or better prevents artificial electrical runout signals.
• Setting the Operating Gap: Thread the probe into its mounting bracket while checking the DC bias voltage at the Proximitor Sensor's terminal strip or buffered output port. Turn the body until the meter shows -10.0 Vdc, marking the precise midpoint of the 2.0 mm linear tracking envelope.
• Radial Clearance Requirements: Provide a minimum counterbore diameter of 30 mm (1.2 inches) surrounding the 8 mm tip to prevent side-view interference from the mounting bracket structure.
• Preventing Sensor Cross-Talk: When installing two sensors in an X-Y configuration on the same bearing face, separate the probe tips by a minimum of 40 mm (1.6 inches). This prevents overlapping RF fields from causing cross-talk noise interference.
• Torque and Locking Safety: Once the -10.0 Vdc gap voltage is confirmed, secure the position by tightening the 3/8-24 UNF hex locknut. Do not exceed the structural limit of 11.2 N·m (100 in·lb). Run lockwire through the predrilled nut holes to secure the assembly against continuous shaft frequency vibration.

Product Advantages

• Excellent Thermal Performance: Designed to exhibit minimal scale factor drift across its full temperature operating profile, ensuring true measurements during extreme turbine startups.
• Tool-Less ClickLoc Connectors: Features gold-plated brass coaxial connectors that engage with a positive click. This design resists terminal corrosion and vibration detachment without requiring special crimping tools.
• Robust Mechanical Design: Built using proprietary TipLoc molding to chemically fuse the ceramic tip to the stainless steel body casing, complemented by CableLoc design offering 330 N of continuous wire pull-strength relief.
• Maximum Routing Flexibility: The unarmored cable option provides a tight bend radius, allowing for smooth, zero-resistance routing paths inside tight internal machine cavities or dedicated external conduit junctions.
• Hot-Swap Capability: Manufacturing standards allow the probe, cable, or Proximitor sensor to be replaced independently without requiring any field calibration.

Ordering Information

Procurement Note: For new installation drop-ins, verify your required total loop length (5.0m or 9.0m) to ensure the matching 3300 XL Extension Cable and Proximitor Sensor are requested concurrently with this probe.

Logistics and Shipping

To preserve precision hardware calibration during global transport, all products are handled with industry-standard instrument packing steps:

Professional Packaging Protocol:

Every Bently Nevada 330104 probe is sealed inside an anti-static industrial packaging shield to isolate the internal eddy-current components from static discharge hazards. The sensor head and its flexible unarmored cable are cradled within custom-cut, high-density shock protection foam liners inside a heavy-walled corrugated structural shell. This eliminates the risk of impact crimping, connector flattening, or drop damage during long-distance international air or sea cargo shipping.

Frequently Asked Questions

• Can a 3300 XL 8 mm probe be connected directly to a legacy 7200 series Proximitor sensor?

  No. The 3300 XL 8 mm system operates on a different electrical design, utilizing a standard scale factor of 7.87 V/mm (200 mV/mil). Attempting to mix it with a 7200 series sensor will corrupt the linear range and destabilize the calibration. Always match the probe with a corresponding 3300 XL Proximitor.

• What is the maximum allowable physical distance between the proximity probe and the Proximitor sensor?

  The total system electrical length must be strictly maintained at either 5.0 meters or 9.0 meters (determined by your Proximitor model). This total includes both the integrated probe cable and the extension cable. Altering this total length shifts the tuning frequency and introduces major measurement errors.

• How does crosstalk affect closely mounted 330104 proximity probes, and how can it be avoided?

  When two probe tips are mounted too close together, their radio frequency (RF) fields intersect, causing signal modulation interference (crosstalk). To prevent this in radial vibration setups, maintain a minimum physical separation of 74 mm (2.9 in) between probe tips, or 40 mm (1.6 in) for axial position arrangements.

• Does the cable construction on the 330104 series restrict its minimum bend radius?

  Yes. While this unarmored variant offers higher flexibility than armored versions, you must still maintain a strict minimum bend radius of 25.4 mm (1.0 in) during installation routing. Bending or kinking the coaxial cable past this threshold damages the internal coaxial shielding layers, altering system impedance and destroying accuracy.

• How do you verify if a 330104 probe has suffered an internal short or open circuit in the field?

  You can diagnose the probe's health using a standard digital multimeter to check resistance across the center conductor and the outer shield of the coaxial connector. A normal, uninstalled 3300 XL 8 mm probe typically reads between 5.0 Ω and 11.0 Ω (depending on the integrated cable length). A reading near 0 Ω indicates a short, while an infinite reading indicates an open circuit.