Configured for eddy-current displacement transduction in TSI networks, the Bently Nevada 330881-28-16-155-03-02 (330881 PROXPAC XL Proximity Transducer) provides direct physical execution of probe-to-target gap measurement via integrated 3300 XL 8 mm probe and Proximitor sensor.

Suffix Breakdown & Model Matrix

• 330881: Base model, PROXPAC XL Proximity Transducer Assembly
• -28-: 3300 XL 8 mm probe with Multiple Approvals
• -16-: Standoff Adapter Option 160 mm
• -155-: Probe Penetration Option 155 mm
• -03-: One M20 fitting, two plugs
• -02: Mounting Thread Option 3/4-14 NPT
• Metric: Metric specification variant

Physical & Electrical Data

Eddy-Current Probe Scaling & Gap Validation

Eddy-current probe scaling for the 3300 XL 8 mm system follows a linear range of 2 mm with sensitivity near 7.87 V/mm (200 mV/mil). Gap voltage validation targets -10 VDC at mid-scale to maintain rotor dynamics measurement linearity. Cross-talk suppression is achieved via shielded FluidLoc cabling and PPS housing conductivity to dissipate electrostatic charges in high-noise TSI environments.

Ordering info

• 1 x Bently Nevada 330881-28-16-155-03-02 PROXPAC XL Proximity Transducer Assembly (Metric)
• Note: Accessories, manuals, calibration data, separate extension cables, and Proximitor housings are not included unless explicitly listed.

Site Mounting Rules

• Engage 3/4-14 NPT threads with minimum 5 full thread engagements into the process connection.
• Secure housing cover to allow external probe tip gap adjustment without disassembly.
• Maintain minimum bend radius on 75 Ohm triaxial FluidLoc cable; protect with AISI 304 stainless steel armor in high-vibration zones.
• Terminate shield drain wire at monitor end only to prevent ground loops; do not short shield to PPS housing.

Technical Inquiries

• Does the PROXPAC XL 330881 support hot-swap replacement on live machinery?

  No. The integrated Proximitor sensor and probe assembly must be installed with power removed from the monitor loop to prevent transient overvoltage to the conditioning circuit and erroneous TSI trip signals.

• What is the backplane or loop current load of this transducer?

  The 3300 XL Proximitor sensor inside the housing draws excitation current from the connected monitor (e.g., 3500 series). Typical loop load is defined by the monitor's Proximitor interface; the transducer itself presents a fixed impedance probe coil (~50 to ~550 Ohm depending on gap).

• Is the PPS housing conductive for EMI shielding?

  Yes. The Polyphenylene Sulfide (PPS) incorporates conductive fibers to strengthen the structure and dissipate electrostatic charges, but it does not replace metallic Faraday shielding. Proper cable shielding termination is required.

• Can a standard 3300 XL extension cable be added between the probe and housing?

  No. The PROXPAC XL integrates the probe, extension cable, and Proximitor into a single housing. No separate extension cable is used or supported between the probe and sensor inside the assembly.

• What gap voltage range is valid for commissioning?

  Typical gap voltage validation uses -9 to -11 VDC at installed position. The -10 VDC nominal target corresponds to mid-linear range of the 8 mm probe (approx 1 mm gap). Field adjustment must follow the monitor's bias voltage verification procedure.

• Does the M20 fitting support conduit entry?

  Yes. The -03 option provides one M20 fitting with two plugs for cable entry or conduit adaptation. Use only metric glands rated for IP66/Type 4X to maintain enclosure integrity.

• Is the 160 mm standoff adapter fixed or removable?

  The standoff adapter option defines the assembly configuration. In 330881 PROXPAC XL, the housing and adapter are configured per order code; mechanical alteration in field is not supported and voids approval ratings.

• What happens if the probe penetration exceeds 155 mm specification?

  The -155- suffix defines probe penetration length. Exceeding or modifying this changes the effective probe tip position relative to the standoff and may result in loss of linear measurement range or mechanical interference with rotor/housing internals.