Bently Nevada 21000-30-10-00-078-04-02 Proximity Probe Housing Assembly

Product Overview

The 21000-30-10-00-078-04-02 is a specialized Proximity Probe Housing Assembly from Bently Nevada, designed to provide robust mechanical protection and environmental sealing for vibration monitoring sensors. This assembly is specifically configured for the 3300 XL 11 mm proximity probe, a high-performance sensor used for measuring fluid-film bearing clearances, shaft vibration, and axial position in large rotating machinery such as turbines, compressors, and pumps.

Product Status Note: This specific part number has been superseded by 21000-29-10-00-078-04-02. While the 21000-30 configuration remains a common sight in legacy installations, new projects and replacements typically transition to the updated 21000-29 series to maintain compliance with the latest global certification standards.

Technical Configuration

The part number breakdown reveals the specific mechanical and electrical interface of this assembly:

• Probe Option (30): Integrated with a 3300 XL 11 mm probe, featuring multiple global approvals (ATEX, CSA, etc.) for use in hazardous areas.

• Cable Length (10): Includes a 1.0 metre (39 in) probe cable, intended for connection to a Proximitor sensor or extension cable.

• Probe Penetration (078): A penetration depth of 7.8 inches (198 mm) into the machine casing, allowing the probe tip to be accurately positioned relative to the target shaft.

• Mounting & Fittings (04/02): Utilizes a standard 3/4-14 NPT mounting thread and includes a single 3/4-14 NPT plug for sealing the housing conduit entry.

• Housing Protection: The aluminum or stainless steel housing protects the probe's delicate cable connection from moisture, oil, and mechanical damage common in industrial environments.

Technical Specifications

Technical FAQs

Why was the 21000-30 replaced by the 21000-29?

Bently Nevada often updates part numbers to reflect changes in manufacturing processes or to consolidate global certifications. The 21000-29 version typically provides identical mechanical fit and form but ensures compliance with current hazardous area directives and material standards.

What is the purpose of the "No Standoff Adapter" (00) option?

The "00" option means the housing mounts directly to the machine casing or a threaded boss without an intermediate spacer. This is used when the 7.8-inch penetration depth is sufficient to reach the target without needing extra clearance for the housing body.

Can I use a 3300 XL 8 mm probe in this housing?

This specific assembly is bored and tapped for the 11 mm probe. While the housing bodies look similar, the internal mounting and cable management are optimized for the 11 mm diameter probe head and its specific connector size.

Engineering & Installation Guide

• Gap Setting: Before final tightening, use a voltmeter or a Bently Nevada TK-3 calibration tool to set the probe gap (typically -9.0 VDC for the 3300 XL 11 mm system). Accurate gapping is critical for linear measurement range.

• Thread Sealing: Use appropriate thread sealant on the 3/4-14 NPT mounting threads to prevent oil leaks from the machine casing. Ensure the sealant is compatible with the machine's lubrication oil.

• Cable Management: When installing the probe into the housing, ensure the cable is not twisted or pinched. Use the internal cable transition to provide strain relief for the 1.0-metre lead.

• Conduit Connection: Always ensure the NPT plug or the connected conduit is tightened to maintain the NEMA 4X or IP66 rating of the housing, protecting the internal electronics from the elements.