330191-00-08-05-CN Bently Nevada 3300 XL 8 mm ETR Probe | 0.5 m

What Is the Bently Nevada 330191-00-08-05-CN?

The 330191-00-08-05-CN is a Bently Nevada 3300 XL 8 mm ETR proximity probe. It is designed for precise, non-contact measurement in rotating machinery protection systems. This model uses a 3/8-24 UNF thread and comes without armor. Its 0.5 meter total length makes it suitable for installations with short reach requirements. The probe features a patented TipLoc molding method for a robust bond between tip and body. Additionally, the CableLoc design provides 330 N (75 lbf) pull strength. These engineering-grade details ensure reliable performance in demanding industrial environments.

Key Specifications of the 330191-00-08-05-CN

• Input Voltage: Requires -17.5 Vdc to -26 Vdc when installed with nonincendive circuit per drawing 140979.
• Output Resistance: 50 Ω.
• Nominal Probe DC Resistance: 7.45 ± 0.50 Ω at 0.5 m.
• Total Length: 0.5 meter (1.6 feet).
• Thread: 3/8-24 UNF, maximum thread engagement 0.563 in.
• Probe Case Material: AISI 303 or 304 stainless steel.
• Probe Tip Material: Polyphenylene sulfide (PPS).
• Connector Material: Gold-plated brass or gold-plated beryllium copper.
• Maximum Connector Torque: 0.565 N•m (5 in•lbf).
• Tensile Strength: 330 N (75 lbf) probe case to lead; 270 N (60 lbf) at extension cable connectors.

These precise electrical specifications ensure compatibility with Bently Nevada extension cables and Proximitors. The 8 mm probe diameter offers a thicker encapsulation of the probe coil, resulting in a more rugged design against physical abuse.

Applications and Use Cases

Because of its robust construction, the 330191-00-08-05-CN is ideal for continuous monitoring of critical rotating equipment. For instance, it can be used in steam turbines, compressors, and pumps where vibration and axial position must be tracked. The 0.5 meter length suits installations with limited space, such as bearing housings. Furthermore, the probe's ability to seal differential pressure between tip and case (via Viton® O-ring) makes it appropriate for environments with pressure variations. In high-temperature applications, the ETR (Extended Temperature Range) cable option allows operation up to +232°C for T1 classification. However, note that probes are not pressure tested prior to shipment. Therefore, always verify suitability for your specific process conditions.

Installation and Maintenance Guidance

Proper installation is critical for accurate measurements. First, ensure the probe is mounted with the correct thread engagement. The maximum thread engagement is 0.563 inches, so avoid over-tightening. Use a torque wrench to apply no more than 0.565 N•m (5 in•lbf) to the connector. Additionally, verify that the input voltage stays within -17.5 Vdc to -26 Vdc for nonincendive circuits. Operation at a more positive voltage than -23.5 Vdc can reduce linear range. For maintenance, inspect the probe tip and cable periodically for wear or damage. Since the probe uses a Viton® O-ring seal, check for leaks if used in differential pressure applications. Always follow the manufacturer's safety manual for any service. The 3300 XL series is known for engineering-grade precision, and this probe is no exception.