Bently Nevada 330881-28-04-110-06-02 PROXPAC XL Replacement

Product Overview

Bently Nevada 330881-28-04-110-06-02 PROXPAC XL: Seamless Replacement & Upgrade Solution

The Bently Nevada 330881-28-04-110-06-02 is a PROXPAC XL Proximity Transducer Assembly engineered for continuous shaft vibration and position monitoring in rotating machinery protection systems. As legacy 3300 Series and 7200 Series field installations age and OEM support windows close, plant engineers and reliability teams are actively sourcing verified replacement units to maintain uninterrupted machinery protection coverage. This listing provides a fully tested, ready-to-ship replacement for the 330881-28-04-110-06-02, backed by a 12-month warranty and pre-shipment functional verification.

The PROXPAC XL assembly integrates the proximity probe, extension cable, and Proximitor® sensor into a single pre-configured package, eliminating field calibration variables that arise when individual components are sourced separately. The 28 mm probe tip diameter, 4 mm nominal gap, 110 mV/mil (4.33 V/mm) scale factor, and -24 VDC supply voltage are factory-set and verified, ensuring direct compatibility with Bently Nevada 3500 Series rack-mounted monitors — including the 3500/42M Proximitor/Seismic Monitor and the 3500/40M Proximitor Monitor — without requiring reconfiguration of the monitor’s transducer input parameters.

For facilities migrating from older 7200 Series proximity systems or decommissioning standalone Proximitor® sensor assemblies such as the 330180 or 330130 series, the 330881-28-04-110-06-02 PROXPAC XL provides a consolidated replacement path. The integrated cable assembly (110 cm armored extension) preserves existing conduit routing in most installations, and the standard 5/8-28 UNF probe thread is compatible with existing probe holders and brackets, minimizing mechanical rework during a planned outage window.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration from a legacy proximity system to the 330881-28-04-110-06-02 PROXPAC XL typically involves more than a single transducer swap. In most 3500 Series rack installations, the transducer connects to an input terminal block on the 3500/20 Rack Interface Module, which manages power distribution and I/O routing for the entire protection rack. Verifying the terminal block wiring pinout against the PROXPAC XL’s signal, common, and power leads is the first step before energizing the replacement unit.

Where the existing installation uses a 3500/42M Proximitor/Seismic Monitor with dual-channel configuration, both channels should be inspected simultaneously — replacing only the failed channel while leaving an aged companion transducer (such as a 330730 or 330780 series probe) in service introduces asymmetric measurement uncertainty that can mask early-warning vibration trends. Pairing the new 330881-28-04-110-06-02 with a matched replacement on the companion channel ensures consistent scale factor and gap characteristics across both measurement planes.

For facilities upgrading from standalone 330180 Proximitor® Sensor assemblies, the transition to the integrated PROXPAC XL format eliminates the separate Proximitor housing and its associated field wiring junction. This reduces the number of potential failure points in the signal chain and simplifies the cable routing inside the machinery protection enclosure or junction box. In installations where the existing conduit run exceeds the 110 cm integrated cable length, a 330130 Series Extension Cable can be added between the PROXPAC XL output connector and the monitor rack terminal, maintaining signal integrity without introducing additional active components.

Communication between the 3500 rack and the plant DCS or safety system typically passes through a 3500/92 Communication Gateway Module using Modbus RTU, FOUNDATION Fieldbus, or Profibus DP, depending on the plant’s control architecture. The replacement of a transducer assembly does not require reconfiguration of the gateway module, but a channel reset and OK relay verification on the 3500/32 4-Channel Relay Module is recommended after installation to confirm that the new transducer’s output is within the monitor’s OK band before returning the machine to service.

In turbomachinery applications where the 330881-28-04-110-06-02 is used for axial position monitoring alongside radial vibration channels, the associated 3500/45 Position Monitor should be checked for correct gap voltage setpoints after installation. The PROXPAC XL’s factory-set 1.0 mm nominal gap corresponds to approximately -10.4 VDC at the Proximitor output; confirming this reading at the monitor’s front-panel display before closing the machine confirms correct assembly and eliminates the most common source of post-maintenance nuisance trips.

Retrofit Guidance FAQ

Q: Can the 330881-28-04-110-06-02 replace a 7200 Series proximity assembly directly?
A: Not without verifying the monitor’s scale factor setting. The 7200 Series typically uses a 100 mV/mil scale factor, while the PROXPAC XL uses 110 mV/mil. The 3500 Series monitor must be reconfigured to 110 mV/mil (or the equivalent 4.33 V/mm) before the replacement unit is placed in service. Failure to update this setting will result in incorrect vibration amplitude readings and may cause spurious alarms or missed trips.

Q: Is field gap calibration required after installation?
A: No. The PROXPAC XL is factory pre-calibrated. However, the physical air gap between the probe tip and the target shaft must still be set mechanically to the 1.0 mm nominal value using a feeler gauge or gap voltage measurement (-10.4 VDC ±0.5 VDC) before the machine is started. The factory calibration ensures the electrical scale factor is correct; the mechanical gap must be set on-site.

Q: What is the wiring configuration for the 330881-28-04-110-06-02?
A: The PROXPAC XL output connector uses a standard Bently Nevada 3-pin configuration: Pin 1 = Signal (–), Pin 2 = Common, Pin 3 = Power (–24 VDC). This is identical to the 3300 Series PROXPAC wiring convention and is directly compatible with 3500 Series rack terminal blocks without rewiring.

Q: Can this unit be used in a SIL-rated safety instrumented system?
A: The 330881-28-04-110-06-02 is a standard machinery protection transducer and is not independently SIL-certified. For SIL 1 or SIL 2 applications, the complete measurement loop — including the 3500 Series monitor and voting logic — must be assessed as a system. Consult the 3500 Series SIL documentation and your functional safety engineer before deploying in a SIS application.

Q: What communication protocols are supported for remote monitoring?
A: The transducer itself is an analog device; protocol support is determined by the 3500 rack’s communication gateway. The 3500/92 Communication Gateway supports Modbus RTU (RS-485), FOUNDATION Fieldbus H1, and Profibus DP. The replacement of the transducer assembly has no impact on the gateway’s protocol configuration.

Q: How much physical space is required for installation?
A: The 330881-28-04-110-06-02 uses the standard 28 mm PROXPAC XL probe body with a 5/8-28 UNF thread. The probe body length and armored cable routing are identical to the 3300 Series PROXPAC, so no additional clearance or bracket modification is required in most installations. Verify the available axial clearance at the probe tip location before installation if the machine casing has been modified since the original installation.

Warranty Assurance

Every 330881-28-04-110-06-02 PROXPAC XL Proximity Transducer Assembly shipped by TOPNLMS undergoes a pre-shipment functional verification that includes output voltage linearity check across the full gap range, scale factor confirmation at nominal gap, OK relay output verification, and cable continuity and insulation resistance testing. Units that do not meet Bently Nevada’s published specification are quarantined and not shipped.

All units are covered by a 12-month warranty from the date of shipment. Warranty coverage includes replacement or full refund for units that fail under normal operating conditions within the warranty period. Warranty claims are processed within 3 business days of receipt of the returned unit, and replacement units are shipped within 5 business days of claim approval. Expedited replacement is available for critical machinery protection applications — contact our team to arrange advance replacement shipment.

TOPNLMS maintains stock of the 330881-28-04-110-06-02 and related PROXPAC XL assemblies to support urgent replacement requirements. Standard lead time for in-stock units is 3–5 business days to most destinations. Express air freight options are available for critical shutdowns. All units are shipped in original or equivalent protective packaging with full documentation including test records and certificate of conformance.

For procurement inquiries, technical compatibility questions, or urgent replacement support, contact our industrial automation team directly:

📧 [email protected]
📞 +86 18359293191