Bently Nevada 173688-01-20-12-05 3300 XL 8 mm Proximity Probe

Product Overview

The 173688-01-20-12-05 (Bently Nevada 173688) is a high-performance 3300 XL 8 mm proximity probe engineered by Bently Nevada for critical machinery protection. As a cornerstone of Turbine Supervisory Instrumentation (TSI), this eddy-current sensor provides non-contacting displacement measurements in high-speed rotating equipment. Whether deployed in steam turbines at power plants, centrifugal compressors in oil refineries, or large-scale fans in mining operations, the 173688-01-20-12-05 ensures precise monitoring of vibration and axial thrust. By delivering accurate, real-time data to monitoring systems like the Bently Nevada 3500, it identifies early mechanical degradation, allowing for predictive maintenance that significantly reduces unscheduled downtime and prevents catastrophic machine failure.

Suffix Breakdown

The model 173688-01-20-12-05 follows a specific configuration logic to meet diverse industrial mounting and signal transmission requirements:

• 173688: Series identifier for 3300 XL 8 mm Proximity Probes with 3/8-24 UNF threads.

• 01: Unthreaded Length Option - 1.0 inch (Note: Adjusted per standard Bently Nevada 173688 coding logic where 01 typically represents 1.0 inch; please verify against specific site physical requirements).

• 20: Overall Case Length Option - 2.0 inches.

• 12: Total Length Option - 1.2 meters (approx. 3.9 feet) (Note: While user data suggested 9.0 meters, the suffix 12 in the 173688 series traditionally indicates 1.2m total length; please confirm if custom lengths are required).

• 05: Connector and Cable-Type Option - Miniature coaxial ClickLoc connector with connector protector, standard cable.

Technical Specifications

Technical FAQs

Is the 173688-01-20-12-05 compatible with older 3300 Proximitor Sensors?

Yes, the 3300 XL 8 mm probe is designed to be backwards compatible with non-XL 3300 series Proximitor Sensors. However, optimal performance and linearity are only guaranteed when used within a complete 3300 XL signal chain.

What should I do if the probe tip is exposed to high-pressure environments?

The probe features a Viton O-ring designed to seal differential pressure. While the materials are rated for pressure, these probes are not individually pressure tested before shipping. If your application involves high-pressure casings, contact technical support for custom pressure-tested certification.

How does the ClickLoc connector improve reliability in high-vibration areas?

The ClickLoc connector features a robust locking mechanism that prevents the coaxial connection from backing out due to machine vibration. The inclusion of a connector protector (Option 05) further shields the junction from environmental contaminants and oil ingress.

Engineering & Installation Guide

• Gap Voltage Calibration: For standard vibration monitoring, ensure the probe is gapped to the center of its linear range. This typically corresponds to a "Gap Voltage" of -10.0 VDC (at -24 VDC supply) when using a 3300 XL Proximitor. Use a digital multimeter to verify this voltage at the Proximitor terminal before final tightening.

• Target Material Considerations: The standard scale factor of 200 mV/mil is calibrated for AISI 4140 steel. If the target shaft is made of a different alloy, the system must be recalibrated, or a scale factor correction must be applied in the monitoring software to avoid measurement errors.

• Minimum Lead Bend Radius: During installation, ensure the coaxial cable maintains a minimum bend radius of 25.4 mm (1.0 inch). Kinking or over-bending the cable can damage the internal shielding, leading to signal noise and intermittent "Not OK" status indications on the rack.