330171-20-55-05-02-CN Bently Nevada 5mm Proximity Probe

Is Your Rotating Machinery Measurement Chain Introducing Signal Errors?

In turbomachinery condition monitoring, even minor inconsistencies in probe geometry or cable impedance can degrade measurement integrity. The Bently Nevada 330171-20-55-05-02-CN addresses this challenge through verified engineering-grade construction. This 3300 series 5mm probe delivers precise displacement measurement for critical rotating equipment.

330171-20-55-05-02-CN Technical Specifications

This probe operates within a -17.5 Vdc to -26 Vdc power supply range with 12 mA maximum consumption. The output resistance is 50 Ω, and the probe DC resistance from center conductor to outer conductor measures 7.45 ± 0.50 Ω at 0.5 meter length. Sensitivity remains below 2 mV output voltage change per volt input voltage change. The probe tip uses polyphenylene sulfide (PPS), while the case is AISI 304 stainless steel. The 1/4-28 UNF thread requires a #3 or larger tap drill for mounting. Maximum thread engagement is 0.375 in. The unthreaded length is 2.0 in, overall case length is 5.5 in, and total cable length is 0.5 meter (1.6 feet). The miniature coaxial ClickLoc connector ensures secure termination. Weight is 0.323 Kg.

Key Performance Characteristics

• Operates from -17.5 Vdc to -26 Vdc with 12 mA maximum current draw.
• Output resistance of 50 Ω supports stable signal transmission.
• Probe DC resistance: 7.45 ± 0.50 Ω at 0.5 m length.
• Supply sensitivity below 2 mV per volt ensures measurement stability.
• PPS probe tip and AISI 304 SST case provide chemical and mechanical durability.
• Temperature range: -35°C to +177°C (-31°F to +351°F).
• ClickLoc miniature coaxial connector enables reliable cable interface.
• Recommended probe case torque: 5.1 N·m (45 in·lb); maximum 7.3 N·m (65 in·lb).

Installation and Integration Notes

When drilling and tapping a mounting hole for this 1/4-28 probe, use a #3 or larger tap drill. Apply the recommended probe case torque of 5.1 N·m (45 in·lb) and never exceed 7.3 N·m (65 in·lb). The minimum cable bend radius is 25.4 mm (1.0 in). For connector-to-connector torque, refer to the official Bently Nevada documentation. This probe integrates with 3300 series monitoring systems. When wiring into fieldbus networks, confirm gateway or connection module requirements with the supplier.

Reliability and Environmental Considerations

The AISI 304 stainless steel case and PPS tip resist harsh industrial environments. However, exposing the probe to temperatures below -34°C (-30°F) may cause premature pressure seal failure. Therefore, verify process conditions remain within the -35°C to +177°C range. Periodic inspection of cable integrity and connector seating supports long-term measurement accuracy. The 222 N (50 lbf) tensile strength between probe case and lead, as well as lead to extension cable connectors, ensures mechanical robustness.