330171-00-20-05-02-CN | Bently Nevada 5mm Probe 1/4-28 UNF

Solving the Challenge of Precision Vibration Monitoring

In rotating machinery, even a slight shaft displacement can signal developing faults. When you need reliable, repeatable vibration data in tight spaces, the Bently Nevada 330171-00-20-05-02-CN delivers. This 5mm proximity probe, part of the 3300 series, is engineered for accurate measurement of shaft vibration and position in critical turbomachinery, pumps, and compressors. Its compact 5mm tip and threaded 1/4-28 UNF mounting make it ideal for installations where space is limited but precision is non-negotiable.

What Makes This Probe Stand Out?

The 330171-00-20-05-02-CN is built for harsh industrial environments. The probe tip is made of polyphenylene sulfide (PPS), a rugged thermoplastic that resists chemicals and wear. The probe case is constructed from AISI 304 stainless steel (SST), offering excellent corrosion resistance and mechanical strength. With a weight of only 0.323 kg, it is lightweight yet durable, reducing stress on mounting points. The miniature coaxial ClickLoc connector ensures a secure, quick connection, while the standard cable length of 0.5 meters (1.6 feet) suits many installations.

Technical Specifications at a Glance

Product Type: 330171 3300 5mm Probe, 1/4-28 UNF thread, without armor

Unthreaded Length Option: 00 = 0 in

Overall Case Length Option: 20 = 2 in

Total Length Option: 0.5 meter (1.6 feet)

Connector Option: Miniature coaxial ClickLoc connector, standard cable

Agency Approval Option: CN (Country Specific)

Probe Tip Material: Polyphenylene sulfide (PPS)

Probe Case Material: AISI 304 stainless steel (SST)

Weight: 0.323 kg

Probe Case Thread: 1/4-28

Maximum Length of Thread Engagement: 0.375 in

Electrical and Mechanical Performance

The probe operates with a power supply of -17.5 Vdc to -26 Vdc, consuming a maximum of 12 mA. This low power draw makes it efficient for continuous monitoring. The output resistance is 50 W, and the probe DC resistance is 7.45 ± 0.50 Ω, ensuring stable signal transmission. The probe cable is a 75 Ω triaxial, fluoroethylene propylene (FEP) insulated cable, available in lengths of 0.5, 1, 2, 5, or 9 meters (1.6, 3.3, 16.4, or 29.5 feet). This flexibility allows you to choose the right cable length for your setup.

Built to Withstand Harsh Conditions

Temperature extremes can cripple standard sensors. The 330171-00-20-05-02-CN operates over a wide temperature range of -35°C to +177°C (-31°F to +351°F), making it suitable for demanding applications. The probe case torque is recommended at 5.1 N·m (45 in·lb), with a maximum of 7.3 N·m (65 in·lb), ensuring secure installation without damage. The connector-to-connector torque has a maximum of 0.565 N·m (0.42 ft·lbf), and the minimum cable bend radius is 25.4 mm (1.0 in), allowing for flexible routing in tight spaces.

Industry Applications

This probe excels in several critical applications:

Turbomachinery Monitoring: Measure shaft vibration in steam and gas turbines to detect imbalance, misalignment, or bearing wear early.

Pump and Compressor Protection: Monitor axial displacement and radial vibration in pumps and compressors to prevent catastrophic failures.

General Rotating Equipment: Ideal for any rotating shaft where precise proximity measurement is required, including motors, generators, and gearboxes.

Installation and Setup Guidance

Proper installation is key to accurate readings. When drilling and tapping a mounting hole for a 1/4-28 probe, a #3 or larger tap drill is recommended. Ensure the probe is gapped correctly—typically at 1.27 mm (50 mils) for optimal linear range. The probe case thread is 1/4-28, and the maximum length of thread engagement is 0.375 in. Use the recommended torque values to avoid over-tightening, which can distort the probe or damage the threads.

Maintenance and Reliability

Regular inspection of the probe and cable is essential for long-term reliability. Check for any signs of wear, corrosion, or damage to the cable insulation. The PPS tip and stainless steel case are designed to resist environmental degradation, but periodic cleaning with a soft cloth and mild solvent can help maintain performance. Avoid exposing the probe to temperatures below -34°C (-30°F), as this may cause premature failure of the pressure seal.

Selection Guide and Purchasing Advice

Before ordering, verify the total length option (0.5 meter in this case) and the connector type (miniature coaxial ClickLoc). If you need a different cable length, options include 1, 2, 5, or 9 meters. The agency approval option is CN (Country Specific), so confirm this matches your regional requirements. For expert advice and competitive pricing, contact BluePLC Industrial. We are a trusted supplier of industrial automation parts, ensuring genuine Bently Nevada products and fast delivery.

Why Choose BluePLC Industrial?

At BluePLC Industrial, we understand that downtime is costly. That's why we stock genuine Bently Nevada parts like the 330171-00-20-05-02-CN, ready to ship. Our team of automation specialists can help you select the right probe for your application, answer technical questions, and provide ongoing support. With our commitment to quality and customer service, you can trust us to keep your machinery running smoothly.

Final Thoughts

The Bently Nevada 330171-00-20-05-02-CN is a precision instrument designed for demanding vibration monitoring applications. Its robust construction, wide temperature range, and accurate performance make it a smart investment for any rotating equipment protection system. Contact BluePLC Industrial today to place your order or to learn more about how this probe can benefit your operations.