330172-20-55-05-02-CN | Bently Nevada 5mm Probe with Armor

Product Overview

When unplanned downtime threatens your rotating machinery, the Bently Nevada 330172-20-55-05-02-CN delivers the precise vibration data you need to act before failure occurs. This 5mm proximity probe, part of the 3300 series, is engineered for reliable shaft displacement and eccentricity monitoring in critical applications like turbines, compressors, and pumps.

The 330172-20-55-05-02-CN features a rugged AISI 304 stainless steel case and a polyphenylene sulfide (PPS) tip, ensuring durability in harsh industrial environments. With a 1/4-28 UNF thread and a 0.5 meter (1.6 feet) total length, this probe integrates seamlessly into existing monitoring systems. The miniature coaxial ClickLoc connector simplifies installation and provides a secure connection.

Technical Specifications

Key parameters of the 330172-20-55-05-02-CN include:

Manufacturer: Bently Nevada

Product Type: 330172 3300 5mm Probe, 1/4-28 UNF thread, with armor

Unthreaded Length: 2.0 inches (20 option)

Overall Case Length: 5.5 inches (55 option)

Total Length: 0.5 meter (1.6 feet)

Connector: Miniature coaxial ClickLoc connector, standard cable

Probe Tip Material: Polyphenylene sulfide (PPS)

Probe Case Material: AISI 304 stainless steel (SST)

Weight: 0.323 kg

Probe Temperature Range: -35°C to +177°C (-31°F to +351°F)

Probe Case Thread: 1/4-28, maximum thread engagement 0.375 inches

Power Supply: Requires -17.5 Vdc to -26 Vdc at 12 mA maximum consumption

Output Resistance: 50 W

Probe DC Resistance (0.5m length): 7.45 ± 0.50 Ω

Probe Cable: 75 Ω triaxial, FEP insulated, available in 0.5, 1, 2, 5, or 9 meters

Tensile Strength: 222 N (50 lbf) probe case to probe lead, and probe lead to extension cable connectors

Probe Case Torque: 5.1 N·m (45 in·lb) recommended, 7.3 N·m (65 in·lb) maximum

Connector-to-Connector Torque: 0.565 N·m (0.42 ft·lbf) maximum

Minimum Cable Bend Radius: 25.4 mm (1.0 in)

Industry Applications

The 330172-20-55-05-02-CN excels in vibration monitoring for rotating equipment. In steam turbines, it provides critical shaft vibration data that helps operators avoid catastrophic failures. In centrifugal compressors, the probe’s accuracy supports efficient surge control and predictive maintenance strategies.

For large electric motors and generators, this sensor enables continuous health assessment, reducing unplanned outages. Its robust construction and wide temperature range make it suitable for demanding environments, from power generation to oil and gas facilities.

Installation and Setup

Proper installation is essential for accurate readings. When mounting the 330172-20-55-05-02-CN, drill and tap a hole using a #3 or larger tap drill for the 1/4-28 thread. Ensure the probe gap is set correctly—typically 1.27 mm (50 mils) for optimal linear range. Use the recommended torque values to avoid damaging the probe or the mounting surface.

The ClickLoc connector simplifies cable attachment, but verify the connection is secure to prevent signal loss. For best results, route the cable with a bend radius of at least 25.4 mm (1.0 in) to avoid stress on the internal conductors.

Maintenance and Reliability

Regular inspection of the probe and cable is recommended to maintain measurement integrity. Check for physical damage, especially at the probe tip and cable connections. Keep the probe clean and free of debris, as contamination can affect sensitivity.

Because the probe is exposed to process temperatures, monitor the ambient temperature to stay within the -35°C to +177°C range. Exposing the probe to temperatures below -34°C (-30°F) may cause premature failure of the pressure seal, so take precautions in cold environments.

Selection and Purchasing Guidance

When ordering the 330172-20-55-05-02-CN, verify the total length, connector type, and agency approval options match your system requirements. This model includes the "CN" agency approval, which is country-specific—confirm compatibility with your local regulations.

BluePLC Industrial offers genuine Bently Nevada parts with reliable availability. Contact our team to confirm current lifecycle status and ensure this probe meets your application needs. We provide expert support to help you select the right sensor for your machinery protection strategy.