330191-00-33-05-CN Bently Nevada 3300 XL 8 mm Proximity Probe

What Causes Premature Proximity Probe Failures in Harsh Machinery Environments?

Physical abuse and fluid ingress are common causes of proximity probe failure in industrial machinery. The Bently Nevada 330191-00-33-05-CN addresses these challenges through a robust 8 mm probe design. This probe is part of the 3300 XL series, known for engineering-grade precision in vibration and position measurement.

330191-00-33-05-CN Product Overview

The 330191-00-33-05-CN is a Bently Nevada 3300 XL 8 mm ETR (Extended Temperature Range) probe. It features a 3/8-24 UNF thread and is supplied without armor. The overall case length is 3.3 inches, and the total length is 0.5 metre (1.6 feet). This probe is designed for use with extension cables and Bently Nevada Proximitors. The patented TipLoc molding method provides a robust bond between the probe tip and body. Additionally, the CableLoc design ensures 330 N (75 lbf) pull strength, enhancing reliability.

Key Specifications of the 330191-00-33-05-CN

• Input Voltage: -17.5 Vdc to -26 Vdc (nonincendive, 12 mA max)
• Output Resistance: 50 Ω
• Nominal Probe DC Resistance: 7.45 ± 0.50 Ω at 0.5 m
• Probe Tip Material: Polyphenylene sulfide (PPS)
• Probe Case Material: AISI 303 or 304 stainless steel
• Cable Type: 75 Ω triaxial, FEP insulated
• Tensile Strength: 330 N (75 lbf) probe case to lead
• Connector Material: Gold-plated brass or beryllium copper
• Maximum Connector Torque: 0.565 N·m (5 in·lbf)
• Probe Weight: 323 g/m (11.4 oz)
• Temperature Range (Probe Only): -55°C to +232°C (T1)

Installation and Integration

Install the 330191-00-33-05-CN using the 3/8-24 UNF thread. The maximum thread engagement is 0.563 inches. Ensure the probe is mounted securely to prevent loosening. Connect the probe to a Bently Nevada extension cable and Proximitor. The system requires a supply voltage of -17.5 Vdc to -26 Vdc. Operation at a more positive voltage than -23.5 Vdc can reduce linear range. For nonincendive circuits, follow installation drawing 140979. The probe seals differential pressure with a Viton O-ring, but it is not pressure tested prior to shipment.

Applications and Use Cases

The 330191-00-33-05-CN is suitable for vibration and position monitoring in turbines, compressors, and other rotating machinery. Its extended temperature range makes it ideal for high-temperature applications. The 8 mm probe diameter offers robustness against physical abuse. Therefore, it is recommended for installations where mechanical stress is a concern. The FluidLoc cable option, available separately, prevents oil leakage through the cable interior.

Maintenance and Reliability

Periodic inspection of the probe tip and cable is recommended. Check for signs of wear, contamination, or physical damage. Ensure connectors are clean and properly torqued to 0.565 N·m (5 in·lbf). The probe's construction with PPS tip and stainless steel case provides durability. However, avoid excessive bending or pulling of the cable beyond rated tensile strength. For specific maintenance procedures, refer to official Bently Nevada documentation.