Product Overview

The Bently Nevada 330702-20-30-10-01-05 3300 XL 11mm Proximity Probe delivers superior performance for applications requiring an extended linear measurement range. As a critical evolution of the 3300 XL transducer family, the 11mm system provides a wider linear range of 4.0 mm (160 mils), making it the definitive choice for monitoring axial position and thrust on large-scale rotating machinery.

This probe excels in high-stakes industrial environments such as utility-scale steam turbines and heavy-duty compressors. It accurately tracks shaft movement in real-time, feeding high-fidelity signals to the Bently Nevada 3500 monitoring rack or DCS. By utilizing a larger 11mm tip, this sensor significantly reduces the "side-viewing" effects often encountered with smaller probes, ensuring absolute measurement stability and preventing false trips in complex Turbine Supervisory Instrumentation (TSI) setups.

Model Configuration & Hardware Logic

330702-20-30-10-01-05 Suffix Decoding

Each parameter in this model number specifies the physical build and regulatory compliance required for heavy-industrial deployment.

Unthreaded Length (-20)

This indicates an unthreaded length of 2.0 inches. This configuration allows the probe to be deeply seated within a mounting bracket while maintaining a rigid, vibration-resistant profile.

Overall Case Length (-30)

The -30 suffix designates a 3.0-inch total case length. This dimension ensures the probe body can penetrate standard bearing housings to reach the target shaft surface effectively.

Total Length (-10)

This represents a 1.0-meter (3.3 feet) integral cable length. This lead must be paired with the correct 3300 XL 11mm extension cable to maintain the precise electrical resonance of the 5.0m or 9.0m system.

Connector Option (-01)

Equipped with a miniature coaxial connector without a protector. This option is typically chosen for installations within dry, protected conduits or specialized enclosures where secondary shielding is already present.

Agency Approvals (-05)

The -05 code confirms Multiple Approvals (ATEX, IECEx, CSA). This enables worldwide deployment in Zone 0 and Class I, Division 1 hazardous areas when installed with the appropriate intrinsic safety barriers.

Technical Performance Profile

Engineering Installation Best Practices

Gap Voltage and Calibration

For 11mm systems, the nominal center of the linear range is typically set to -10.00 VDC. However, because the scale factor is 100 mV/mil (half that of the 8mm system), ensure your 3500/40M or 3500/42M monitor is correctly configured for the 11mm probe type to avoid a 50% measurement error.

Mounting and Target Area

The 11mm probe requires a larger target area than the standard 8mm probe. Ensure the flat surface of the shaft (the target) is at least 30.5 mm (1.2 inches) in diameter. Inadequate target size will lead to non-linear readings and compromised machinery protection.

Cable Integrity

Maintain a minimum bend radius of 25.4 mm (1.0 inch). Avoid routing the probe lead near high-current AC lines. For metric M14 installations, verify thread clearance to prevent seizing during high-temperature operation.

Integrated System Superiority

Unrivaled Thermal Performance

The 3300 XL 11mm series features an advanced polyphenylene sulfide (PPS) tip that resists chemical degradation and thermal expansion. This ensures that DC gap voltage remains consistent even as the turbine housing reaches full operating temperature, eliminating drift-related alarms.

Seamless TSI Connectivity

This probe integrates perfectly with Honeywell Experion PKS or Siemens S7-400 systems via the Bently Nevada 3500 rack. The extended range makes it the ideal sensor for "Differential Expansion" measurements, providing the control room with critical data during machine startup and ramp-up phases.

Robust Mechanical Build

The stainless steel case and internal potting compound protect the sensing coil from high-frequency vibrations and high-pressure oil environments. The gold-plated connectors ensure a low-impedance signal path for decades of service life.

Global Shipping & Logistics

Rapid Project Fulfillment

We guarantee dispatch within 2-7 days when payment finish. Our team coordinates with DHL, FEDEX, and UPS to ensure your critical spares reach the site before scheduled outages or during emergency maintenance windows.

Premium Protective Packaging

Every 330702 probe arrives in New Original Pack condition. We utilize high-density anti-static industrial packaging and reinforced shock-absorbing layers to protect the precision-tuned 11mm tip and coaxial lead during international air transit.

Technical Support FAQ

Q1: Can I use this 11mm probe with an 8mm Proximitor?

A1: No. The 11mm probe must be used with a 3300 XL 11mm Proximitor. The sensing coils have different impedances and resonant frequencies; mixing them will result in a non-functional system.

Q2: What is the main advantage of the 11mm probe over the 8mm?

A2: The 11mm probe provides double the linear range (160 mils vs 80 mils). This is essential for axial thrust monitoring where the shaft may move significantly during different load conditions.

Q3: How do I verify the probe's health in the field?

A3: Using a multimeter, measure the resistance between the center conductor and the shield of the coaxial connector. A healthy 11mm probe usually measures between 5.0 and 12.0 ohms. An open circuit indicates a failed sensor.

Q4: Is the -05 approval necessary for onshore plants?

A4: If the installation area is classified as hazardous (explosive atmosphere), the -05 Multiple Approvals are mandatory for safety and insurance compliance.