Product Overview

The Bently Nevada 330881-28-07-155-03-02 Proxpac XL Housing represents the gold standard in mechanical protection for proximity transducer systems. Specifically engineered for the 3300 XL series, this housing assembly integrates the probe and Proximitor sensor into a single, robust enclosure. It effectively shields sensitive instrumentation from harsh industrial environments, including oil mist, moisture, and mechanical impact. In critical turbomachinery applications—such as steam turbines, centrifugal compressors, and large motors—the Proxpac XL ensures signal integrity and extends the lifespan of vibration monitoring hardware. By consolidating components, it simplifies field wiring and reduces potential failure points in the Turbine Supervisory Instrumentation (TSI) loop.

Model Suffix Analysis

The 330881-28-07-155-03-02 configuration defines specific physical and environmental adaptations for demanding field installations.

Housing Option (-28)

Specifies a 3/4-14 NPT conduit fitting with a high-durability aluminum body, providing superior EMI/RFI shielding and corrosion resistance.

Probe Option (-07)

Designed for the 3300 XL 8mm Proximity Probe with a 3/8-24 UNF thread, optimized for standard displacement and vibration measurements.

Standoff Adapter Length (-155)

Indicates a 15.5-inch standoff length, allowing the probe to penetrate deep machine casings or insulation layers while maintaining a secure external mounting point.

Probe Penetration (-03)

Determines the internal reach of the probe tip, ensuring precise gap voltage settings relative to the target shaft surface.

Mounting Thread Option (-02)

Standardized mounting threads for secure mechanical anchoring to the machine bearing housing or casing.

Hardware Specifications

Field Installation Guidelines

Engineers must verify the Standoff Adapter length against the machine casing thickness before installation. Ensure the O-ring seals are lubricated with system-compatible oil to maintain the IP rating. During the gapping process, use a calibrated voltmeter to monitor the Proximitor output; typically, a -10.00 Vdc bias indicates the center of the linear range for 3300 XL 8mm probes. Maintain a minimum cable bend radius of 25.4mm (1 inch) within the housing to prevent signal attenuation or mechanical fatigue of the coaxial cable.

Operational Excellence

The Proxpac XL series eliminates the need for separate Proximitor housings, significantly reducing the footprint required for instrumentation. Its thermal stability ensures that expansion or contraction of the standoff adapter does not introduce artificial "DC shift" in vibration data. This housing is indispensable for plants operating under API 670 standards, providing the mechanical rigidity necessary for high-fidelity data acquisition in catastrophic failure prevention systems.

Logistics and Handling

Delivery time: 3-5 days when payment finish, BY DHL/FEDEX/UPS.

All units are shipped in original anti-static industrial packaging with factory-sealed moisture barriers. Heavy-duty outer boxing ensures the long standoff adapter remains perfectly straight during international transit.

Engineering Support FAQs

Q1: Can this housing be used with non-XL 3300 probes?

A1: While physically possible, it is optimized for the 3300 XL 8mm system. Using non-XL probes may require different cable adapters and could impact the total electrical length calibration.

Q2: How does the -155 suffix impact the installation depth?

A2: The 155 represents a 15.5-inch standoff. This must be matched with the probe's total length and the "Probe Penetration" suffix to ensure the tip reaches the target shaft within its linear range.

Q3: Is the housing explosion-proof?

A3: The 330881 series is designed to meet various North American (CSA) and International (ATEX/IECEx) standards for hazardous areas when installed with appropriate conduits and seals. Check the nameplate for specific certification codes.