Product Overview

The Bently Nevada 21000-28-05-00-076-04-02 is a specialized proximity probe housing assembly engineered for external mounting on rotating machinery. This high-precision sensor solution provides a stable environment for the integrated 3300 XL 8 mm probe, allowing for the continuous tracking of radial vibration and axial shaft displacement. By utilizing an externally accessible housing, maintenance personnel can adjust or replace probes without disassembling the machine casing. This assembly is a fundamental component of Turbine Supervisory Instrumentation (TSI) systems, ensuring that critical mechanical data is transmitted with high fidelity even under intense thermal and mechanical stress.

Critical Engineering Parameters

• Model Designation: 21000-28-05-00-076-04-02

• Integrated Sensor: 3300 XL 8 mm Proximity Probe

• Probe Lead Length: 0.5 Meters

• Mounting Thread Specification: 3/4-14 NPT

• Penetration Depth: 76 mm (approx. 3.0 inches)

• Thermal Tolerance: -51°C to +177°C (-60°F to +351°F)

• Weight: 0.06 kg

• External Dimensions: 1.8 x 1.6 x 123 cm

• Origin: United States

• Target Material: Ferromagnetic alloys (typically AISI 4140 steel)

Field Deployment and Machinery Integration

This housing assembly is specifically designed for large-scale industrial assets where internal sensor mounting is impractical or impossible. It is frequently applied to monitor the health of centrifugal compressors, steam turbines, and industrial gearboxes. In the power generation and oil and gas sectors, the 21000 series housing allows for precise "gapping" of the probe relative to the shaft surface, which is vital for detecting early signs of bearing wear or rotor instability. Its robust 3/4-14 NPT connection provides a pressure-tight seal, making it suitable for machines with pressurized oil systems or specialized internal atmospheres.

FAQ

Q: Can the 76 mm penetration depth be adjusted after installation?

A: The penetration depth of 76 mm is a fixed physical specification of this specific model (option 076). While minor adjustments can be made via the mounting threads, significant changes in depth require selecting a different model within the 21000 series.

Q: Is this assembly compatible with hazardous area requirements?

A: Yes, the integrated 3300 XL 8 mm probe within the 21000-28-05-00-076-04-02 assembly typically carries multiple international approvals (ATEX, IECEx, CSA) for use in intrinsically safe environments when paired with the appropriate Proximitor sensor.

Q: What is the benefit of using an external housing instead of a standard probe?

A: The external housing protects the probe from environmental contaminants and allows for "hot-swapping" or gapping adjustments while the machine is stationary but pressurized, or during short windows of downtime, without removing the main machine cover.

Q: Does this unit include the Proximitor sensor?

A: No, this model number refers specifically to the housing assembly, the internal probe, and the lead cable. The Proximitor sensor must be purchased separately to match the total system length (typically 5m or 9m).

Q: How does the 0.5-meter cable connect to the rest of the system?

A: The 0.5-meter probe lead terminates in a coaxial ClickLoc connector, which is designed to be joined with a standard 3300 XL extension cable to reach the Proximitor sensor located in a nearby junction box.