330191-00-16-50-CN | Bently Nevada 8 mm ETR Probe, 5 m

What Is the 330191-00-16-50-CN?

The Bently Nevada 330191-00-16-50-CN is an 8 mm extended temperature range (ETR) proximity probe from the 3300 XL series. It measures shaft displacement in rotating machinery with engineering-grade precision. Specifically, this probe uses a 3/8-24 UNF thread and ships without armor. Its 5.0 m total length suits long cable runs between the machine casing and the Proximitor sensor. Because the 3300 XL design incorporates patented TipLoc and CableLoc technologies, the probe resists mechanical abuse and cable pull forces up to 330 N (75 lbf).

Key Specifications of the 330191-00-16-50-CN

• Input voltage: Requires -17.5 Vdc to -26 Vdc when installed with a nonincendive circuit per drawing 140979.
• Current consumption: 12 mA maximum.
• Output resistance: 50 Ω.
• Nominal probe DC resistance: 8.73 ± 0.50 Ω at 5.0 m.
• Probe tip material: Polyphenylene sulfide (PPS).
• Probe case material: AISI 303 or 304 stainless steel.
• Cable: 75 Ω triaxial, FEP insulated.
• Thread: 3/8-24 UNF, maximum thread engagement 0.563 in.
• Total length: 5.0 meters (16.4 feet).
• Overall case length: 1.6 in.
• Agency approval: CN (Country Specific Approval).

Notably, the 8 mm probe body provides a thicker encapsulation of the probe coil in molded PPS plastic. This results in a more rugged probe than smaller-diameter alternatives. Therefore, Bently Nevada recommends 8 mm probes whenever possible for optimal robustness against physical abuse.

Installation and Compatibility

The 330191-00-16-50-CN requires a 5-meter Proximitor sensor for proper operation. One-meter systems do not use an extension cable; however, this 5.0 m probe is designed for use with the 5-meter Proximitor sensor only. When routing the cable, maintain the specified bend radius and secure the probe lead to prevent strain. The maximum connector torque is 0.565 N·m (5 in·lbf). Additionally, the probe case thread is 3/8-24 UNF with a maximum thread engagement of 0.563 in. For hazardous areas, the probe entity parameters are met when used with Bently Nevada extension cables and connected to a Bently Nevada Proximitor. Always follow the installation drawing 140979 for nonincendive circuits.

Maintenance and Reliability

Inspect the probe tip and cable periodically for abrasion, chemical exposure, or mechanical damage. The Viton O-ring seals differential pressure between the probe tip and case. However, probes are not pressure tested prior to shipment. Therefore, verify sealing integrity during scheduled maintenance. The ETR cable option uses PFA insulation for extended temperature range. The standard cable uses FEP insulation. Both cable types maintain 75 Ω triaxial impedance. Because the probe operates from -17.5 Vdc to -26 Vdc, confirm supply voltage stability. Operation at a more positive voltage than -23.5 Vdc can result in reduced linear range.