The Bently Nevada 330881-16-05-150-00-02 PROXPAC XL represents a highly specialized, integrated solution for machinery protection. This unit combines a 3300 XL proximity probe, an extension cable, and a Proximitor sensor into a single, environmentally hardened assembly. Designed specifically for critical assets like steam turbines and centrifugal compressors, the PROXPAC XL simplifies installation by housing the sensitive electronics directly at the measurement point within a rugged, weather-proof enclosure.
By utilizing non-contact eddy current technology, this transducer captures shaft vibration and axial position with microscopic precision. The integrated design eliminates the need for external Proximitor housings and long, unprotected coaxial runs, significantly reducing signal interference and installation costs. Whether monitoring fluid-film bearings or high-speed rotors, the 330881-16-05-150-00-02 ensures maximum uptime by delivering high-fidelity data to your Turbine Supervisory Instrumentation (TSI) system.
The model 330881-16-05-150-00-02 utilizes a modular engineering code to define its mechanical dimensions and electrical calibration:
The -16 specifies a probe with a 1.6-inch (approx. 41mm) total case length. This length determines how far the probe tip extends into the machine housing to reach the target shaft.
The -05 designation indicates a 0.5-inch standoff adapter. This mechanical component adjusts the mounting depth and provides the necessary clearance between the housing and the machine casing.
The -150 signifies a 5.0-meter (16.4 feet) total system length. The internal probe and extension cable are electrically matched to this 5.0m calibration to maintain the industry-standard 200 mV/mil scale factor.
The -00 specifies standard 3/4-14 NPT mounting threads for the conduit port. The -02 option confirms ATEX/IECEx/CSA hazardous area approvals, certifying the unit for safe operation in explosive atmospheres (Class I, Div 2 or Zone 2).
| Feature | Specification Details |
| Transducer Type | Integrated 3300 XL Proximity System |
| Linear Range | 2.0 mm (80 mils) |
| Nominal Sensitivity | 7.87 V/mm (200 mV/mil) |
| Enclosure Rating | Type 4X / IP66 (Weatherproof) |
| O-ring Material | Viton (Probe Tip) / Neoprene (Housing) |
| Input Power | -17.5 VDC to -26 VDC |
| Output Impedance | 50 $\Omega$ |
| Operating Temperature | -35 °C to +85 °C (-31 °F to +185 °F) |
Precision gapping is critical for the integrated PROXPAC XL system:
Connect a digital multimeter to the "OUT" and "COM" terminals within the housing. Rotate the entire assembly to adjust the probe depth until the bias voltage reads -10.0 VDC. This voltage indicates the center of the 80-mil linear range. Once achieved, tighten the locknuts to secure the assembly.
The 330881-16-05-150-00-02 relies on specialized O-rings to maintain housing integrity. Before installation, inspect the Viton O-ring at the probe tip. Lubricate O-rings sparingly with a compatible silicone grease to ensure a pressure-tight seal against moisture and oil.
Use liquid-tight flexible conduit for the wiring exit. Ensure the 3/4-14 NPT threads are sealed with Teflon tape or pipe sealant. This prevents internal condensation, which is the leading cause of electronic failure in outdoor or high-humidity turbine decks.
Integrated Design: By housing the Proximitor sensor inside the probe enclosure, the PROXPAC XL eliminates the vulnerability of external coaxial connections and simplifies the wiring architecture.
Corrosion Resistance: The Type 4X rated housing resists salt spray and corrosive chemicals, making it ideal for offshore platforms and hydrocarbon processing plants.
TSI Compatibility: This unit integrates natively with Bently Nevada 3500/42M monitors, providing immediate access to Orbit plots and time-base waveforms via System 1 software.
API 670 Compliance: The system meets the rigorous standards of the American Petroleum Institute for machinery protection, ensuring global interoperability and safety.
Q1: Does this unit support Ethernet communication?
A1: No. Similar to other proximity sensors, the 330881 provides a raw analog voltage signal. Digital communication (Ethernet/Modbus) occurs only at the 3500 Monitoring Rack level. The "Ethernet router" mention in some databases is a clerical error.
Q2: Can I replace just the probe inside the PROXPAC XL?
A2: While the internal components are technically 3300 XL parts, the PROXPAC XL is factory-assembled as a calibrated system. We recommend replacing the entire assembly to ensure the environmental seals and electrical calibration remain intact.
Q3: How do I verify the sensor is "Gapped" correctly?
A3: Using a voltmeter, measure the DC voltage between the Signal and Common terminals. A reading of -10 VDC represents the ideal mechanical gap. If the voltage is near -1.0 VDC, the probe is too far from the shaft; if it is near -18 VDC, the probe is likely touching the shaft.
Q4: Is the -02 approval option suitable for hazardous areas?
A4: Yes. The -02 option provides multi-agency certifications (ATEX, IECEx, CSA), allowing for installation in Zone 2 or Division 2 hazardous locations without requiring additional explosion-proof housings.
