Product Overview
When machinery vibration threatens uptime, the Bently Nevada 21000-28-05-20-051-04-02 provides a robust, explosion-proof housing for 8 mm proximity probes. This Industrial Automation Module is engineered for continuous monitoring in demanding environments, ensuring accurate data transmission for predictive maintenance. As part of the 21000 series, this assembly combines an aluminum body with a 304 stainless steel sleeve, delivering both durability and corrosion resistance. The 21000-28-05-20-051-04-02 is factory-packed and comes with a 12-month warranty, making it a reliable choice for critical rotating machinery.
Technical Specifications
The table below lists the key specifications for the Bently Nevada 21000-28-05-20-051-04-02. These values are critical for ensuring proper fit and function in your monitoring system.
| Parameter |
Value |
| Probe Option |
3300 XL 8 mm probe, with connector (selectable hazardous area approvals) |
| Probe Cable Length |
0.5 m (20 in) |
| Standoff Adapter |
2 in |
| Probe Penetration |
5.1 in (051) |
| Fitting Option |
One 3/4-14 NPT plug only (04) |
| Mounting Thread Option |
3/4-14 NPT (02) – must be ordered when standoff adapter length is not 00 |
| Material |
Aluminum body with 304 stainless steel sleeve |
| Maximum (C) + (D) Dimension |
13.5 in (34.3 mm) – with 0.5 m probe cable length (visible probe P/N and S/N not visible) |
| Weight |
1.1 kg (2.4 lb) typical, without fittings |
Industry Applications
The 21000-28-05-20-051-04-02 is designed for externally mounted proximity probe housings, fully compliant with API 670 Standard. Typical applications include:
- Vibration monitoring on turbines, compressors, and pumps in oil & gas facilities.
- Hazardous area installations where explosion-proof certification is mandatory, such as chemical plants and refineries.
- Rotating machinery protection in power generation and heavy industry.
In each scenario, the housing ensures stable probe placement and protection, enabling accurate shaft displacement and eccentricity measurements that drive predictive maintenance programs.
Installation & Setup Guidance
Proper installation is crucial for accurate readings. Follow these steps:
- Verify that the mounting thread (3/4-14 NPT) matches your machine's tapping. The 21000-28-05-20-051-04-02 includes this thread option; ensure it is ordered if your standoff adapter length is not 00.
- Attach the optional standoff adapter (2 in) to position the probe at the correct distance from the shaft. The probe penetration is 5.1 in, so adjust accordingly.
- Connect the probe cable (0.5 m) to the reverse mount proximity probe, ensuring a secure connection to avoid signal loss.
- Seal all threaded ports with the provided plug (one 3/4-14 NPT plug) and use thread sealant to maintain the explosion-proof rating.
- For hazardous areas, follow the wiring diagram (drawing 140979) to maintain the non-incendive circuit rating.
Maintenance & Reliability
Regular inspection of the housing and probe is essential for long-term reliability. Check the O-rings and thread seal periodically for wear, especially in high-vibration environments. The aluminum body and stainless steel sleeve resist corrosion, but ensure the housing remains clean and free of debris. The CSA Type 4 enclosure rating ensures protection against dust and water, reducing maintenance frequency. By proactively inspecting the assembly, you can avoid unplanned downtime and extend the service life of your monitoring system.
Selection Guide & Purchasing Advice
When ordering the Bently Nevada 21000-28-05-20-051-04-02, verify the following:
- Confirm the probe cable length (0.5 m) meets your installation distance.
- Ensure the standoff adapter length (2 in) and probe penetration (5.1 in) match your machine's geometry.
- Check that the fitting option (one 3/4-14 NPT plug) is sufficient for your conduit connections.
- For North American end users, the CA21000 housing variant is available with additional CSA certifications; for all other regions, the standard 21000 housing is used.
PLC Source PRO is a trusted supplier of authentic Bently Nevada parts, offering new and original products with factory packaging and warranty. Contact us to confirm compatibility with your existing monitoring system.