Configured for eddy-current displacement transduction in TSI networks, the Bently Nevada 330800-28-00-085-03-02 (330800 PROXPAC Proximity Transducer) provides direct physical execution of shaft gap measurement via an integrated 3300 XL 8 mm probe and Proximitor sensor.

Suffix Decoding

• 330800: Base model, PROXPAC Proximity Transducer Assembly (legacy series, English units)
• -28-: 3300 XL 8 mm probe with Multiple Approvals
• -00-: No standoff adapter
• -085-: Probe penetration 8.5 in
• -03-: One 3/4-14 NPT fitting, one 3/4-14 NPT to 1/2-14 NPT SST reducer, two plugs
• -02: Mounting thread 3/4-14 NPT

Hardware Specifications

Eddy-Current Scaling and Gap Validation

The 3300 XL 8 mm probe exhibits 7.87 V/mm (200 mV/mil) sensitivity over a 2 mm linear range. Gap voltage validation targets -10 VDC at mid-scale to preserve rotor dynamics linearity. Cross-talk suppression is enforced by shielded FluidLoc cabling and conductive-fiber housing dissipation; probe coil impedance varies approximately 50 to 550 Ohm across the air gap.

Ordering info

• 1 x Bently Nevada 330800-28-00-085-03-02 PROXPAC Proximity Transducer Assembly (English units, no standoff)
• Note: Calibration sheet, manual, separate extension cable, and standalone Proximitor housing not included unless explicitly listed.

Field Mounting Notes

• Engage 3/4-14 NPT with minimum 5 full thread turns into machine bracket or junction adapter.
• Install SST reducer only when transitioning to 1/2-14 NPT conduit or cable gland.
• Keep 75 Ohm triaxial FluidLoc bend radius within BN 3300 XL limits; use AISI 304 armor in vibrating runs.
• Drain shield at monitor end only; do not bond shield to PPS housing.
• Verify -10 VDC gap bias with power off insertion sequence; do not hot-insert.

Frequently Asked Questions

• Is the 330800-28-00-085-03-02 hot-swappable on a live 3500 monitor?

  No. Integrated Proximitor and probe must be wired with monitor loop de-energized. Live insertion induces transient loop current and can force false gap voltage into the TSI rack.

• What is the electrical load presented to the monitor?

  The assembly draws excitation from the connected Proximitor input (e.g., 3500/42M). Probe coil impedance scales with gap; typical DC resistance spans 50 to 550 Ohm. No separate power terminal exists on the housing.

• Does omitting the standoff adapter change probe linearity?

  No. The -00- option removes the mechanical spacer only. Electrical linear range stays 2 mm at 7.87 V/mm. Penetration length 8.5 in sets tip position relative to machine surface, not scaling.

• Can an external 3300 XL extension cable be spliced in?

  No. PROXPAC integrates probe, FluidLoc cable, and Proximitor in one housing. Adding external extension breaks the calibrated 75 Ohm path and voids gap linearity.

• Are the internal O-rings pressure-rated?

  No. Viton and Neoprene O-rings seal differential humidity and hose water per Type 4X/IP66. They are not rated for internal/external pressure containment. Probes are not pressure-tested at factory.

• What gap voltage is valid during commissioning?

  Acceptable bias is -9 to -11 VDC. -10 VDC marks mid-linear range (~1 mm gap for 8 mm probe). Adjust tip via external access screw on housing cover with monitor in bias-check mode.

• Does the -28- approval option affect electrical performance?

  No. -28- (Multiple Approvals) and -16- (no approvals) share identical eddy-current scaling. Approval variant changes label/certification only, not sensitivity, range, or gap target.

• Is 330800 functionally interchangeable with 330880?

  Yes when suffix options match. 330880 is the current PROXPAC XL catalog number; 330800 is legacy English-unit equivalent. Same 3300 XL 8 mm probe and integrated Proximitor architecture.