Description
Providing reliable mechanical integration for harsh machine environments, the Bently Nevada 330880-28-30-056-01-02 is a specialized PROXPAC XL assembly that combines a proximity probe, standoff adapter, and rugged housing into a singular, field-ready unit. Engineered for continuous monitoring of shaft vibration, axial position, and speed, this assembly houses a 3300 XL 8 mm probe with multi-approval certifications, ensuring safe deployment in hazardous industrial areas. The mechanical package is optimized to protect the delicate sensor and cabling from physical damage, moisture ingress, and ambient contaminants common in heavy rotating machinery applications.
Features
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Integrated 3300 XL 8 mm Probe: Pre-configured with multiple hazardous area approvals (Option 28) for versatile global compliance.
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Rugged Standoff Adapter: Features a 3.0-inch (76 mm) standoff dimension to adjust the probe's clearance and protect it from mechanical interference.
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Precise Probe Penetration: Engineered with a 5.6-inch probe penetration depth (C Dimension) for accurate relative distance measurement.
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Industrial-Grade Fittings: Equipped with one 3/4-14 NPT fitting and two plugs to maintain conduit path integrity.
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Robust NPT Mounting: Features a secure 3/4-14 NPT mounting thread, ensuring rigid mechanical coupling to the machine casing.
Applications
- Steam and gas turbine shaft vibration and axial position monitoring.
- High-speed centrifugal and reciprocating compressor diagnostics.
- Large industrial pumps, fans, and gearbox bearing casing installations.
- Hazardous-area rotating machinery setups requiring certified, explosion-proof, or intrinsically safe proximity measurement systems.
Option Breakdown
| Option Code |
Parameter Category |
Configured Specification |
| 28 |
Probe and Approvals |
3300 XL 8 mm probe with multiple approvals |
| 30 |
Standoff Adapter Option (B Dimension) |
3.0 in (76 mm) |
| 056 |
Probe Penetration Option (C Dimension) |
5.6 in |
| 01 |
Fittings Option |
One 3/4-14 NPT fitting, two plugs |
| 02 |
Mounting Thread Option |
3/4-14 NPT |
Technical Specifications
| Manufacturer |
Bently Nevada |
| Model Series |
PROXPAC XL Proximity Transducer |
| Full Part Number |
330880-28-30-056-01-02 |
| Probe Diameter |
8 mm (3300 XL Series) |
| Standoff Length (B) |
3.0 inches (76 mm) |
| Penetration Depth (C) |
5.6 inches |
| Conduit Thread / Mount |
3/4-14 NPT |
| Country of Origin |
United States (USA) |
| Net Product Weight |
1.44 kg |
| Shipping Weight (Calculated) |
3.00 kg |
Connections and Interfaces
| Interface / Port |
Type |
Function / Connection Assignment |
| Mounting Thread |
3/4-14 NPT Male |
Direct mechanical casing insertion and environmental sealing |
| Fittings Port |
3/4-14 NPT Female |
Configured with one active NPT conduit fitting and two secure plugs |
| Internal Probe Cable |
Coaxial with Miniature ClickLoc Connector |
Connects the internal 3300 XL probe to the external Proximitor Sensor |
Empirical Engineering Insights
Alternative Models & Compatibility
The 330880 PROXPAC XL series utilizes standard 3300 XL 8 mm probes. While the probe core is standard, the mechanical sleeve dimensions (standoff and penetration) are fixed upon manufacturing. Ensure that the combination of your standoff (3.0 in) and penetration (5.6 in) perfectly matches the machine casing profile to achieve correct probe-to-target gap range (typically 50-80 mils/1.27-2.03 mm for standard calibration).
Application Pitfalls & Engineering Notes
Incorrect penetration measurements can lead to catastrophic physical probe contact with the target shaft during start-up or thermal growth phases. Always verify actual shaft clearance before final mechanical torque is applied. The housing must be grounded properly according to local safety codes to prevent electromagnetic noise from distorting the high-frequency RF signal generated by the matched Proximitor Sensor.
Commissioning & Wiring Tips
When routing the internal coaxial cable through the 3/4-14 NPT fitting, ensure you do not exceed the minimum bend radius of the coaxial cable. Always use high-quality thread sealant on the NPT fittings to prevent fluid migrates or moisture from accumulating inside the transducer housing, which can shift the loop capacitance and cause false vibration readings.
Installation Guidelines
CRITICAL WARNING: Ensure the rotating machinery is fully shut down, isolated, and completely stationary before attempting installation. Do not attempt to adjust the standoff adapter or insert the probe penetration assembly while the shaft is in motion. Verify hazardous area classification matches the Probe Option 28 specifications prior to installation in explosive atmospheres.
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1
Clean the machine mounting port and inspect the 3/4-14 NPT mounting threads for debris or damage.
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2
Apply an approved thread sealant to the mounting thread and thread the standoff adapter assembly into the casing port.
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3
Carefully insert the probe into the standoff housing, maintaining axial alignment to avoid bending the tip.
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4
Adjust and lock the penetration depth (5.6 in) while measuring probe gap using a calibrated voltmeter connected to the Proximitor Sensor.
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5
Tighten the conduit fitting and secure the plugs to isolate the internal electrical housing environment.