Bently Nevada 2789-204 7200 Series Proximity Probe Extension Cable

Description

Designed specifically for integration within industrial machinery protection systems, the Bently Nevada 2789-204 provides critical low-loss coaxial signal transmission between proximity probes and proximitor sensors. This high-reliability extension cable features a 17-foot (5.2-meter) length with an engineered 95-ohm characteristic impedance to prevent signal attenuation and phase distortion. Constructed with a fluid-resistant outer jacket, the cable is built to withstand continuous exposure to industrial lubricants, synthetic oils, and moisture in harsh turbine and compressor environments.

Key Features

• Matched 95-Ohm Impedance: Specifically tuned for legacy 7200 Series 5mm and 8mm proximity transducer systems to ensure system-wide calibration accuracy.
• Chemical-Resistant Jacket: Extruded fluoropolymer insulation protects internal conductors against chemical breakdown from hydraulic fluids and industrial solvents.
• Gold-Plated Connectors: High-performance miniature coaxial connectors ensure corrosion resistance and minimal contact resistance over decades of operation.
• Robust Environmental Protection: Designed to maintain physical and electrical integrity across extreme temperature gradients.

Industrial Applications

• Steam turbine radial vibration and axial thrust monitoring.
• Centrifugal compressor shaft displacement sensing.
• High-speed industrial pump shaft relative vibration analysis.
• Hydroelectric generator air gap and shaft runout detection.

Technical Specifications

Connections and Interfaces

Alternative Models & Compatibility

The 2789-204 extension cable is specifically designed for the legacy 7200 Series proximity systems. Note that it is electrically and physically incompatible with newer 3300 XL systems, which require 75-ohm impedance cables. Attempting to cross-connect 7200 and 3300 series transducers will disrupt the proximitor linear output curve, resulting in incorrect measurement readings.

Application Pitfalls & Engineering Notes

When laying out your vibration loop, always verify that the total physical length of the system (probe lead plus extension cable) matches the exact calibration profile of the Proximitor (typically 5.0 meters or 9.0 meters). Using a 17-foot (approx. 5.2m) cable inside a system calibrated for a different overall length will lead to significant voltage-to-distance conversion offsets.

Commissioning & Wiring Tips

Prior to mating, ensure the miniature coaxial connectors are completely clean and dry. Use dedicated connector protector sleeves (silicone or heat-shrink tubing) over mated connections inside junction boxes to prevent moisture ingress, which can create ground loops and skew dynamic vibration signals.

Installation Guidelines