330708-00-20-50-02-00 | Bently Nevada | 3300 XL 11 mm Probe

Technical Overview

The Bently Nevada 330708-00-20-50-02-00 is a high-stability, 11 mm diameter eddy-current proximity probe designed for continuous shaft vibration and position monitoring. It processes AC voltage signals generated by electromagnetic coupling with rotating ferromagnetic targets, converting target displacement into a proportional DC voltage output (−2 to −18 VDC). The probe integrates directly with the 3300 XL 8 mm/11 mm sensor system architecture and connects to 3500 rack-mounted monitors via shielded coaxial cable. It protects the backplane bus by maintaining galvanic isolation (>100 MΩ @ 500 VDC) between probe tip and monitor chassis ground — critical when deployed across multiple zones in Experion PKS or SIMATIC S7-400-based machinery protection systems. Its fixed sensitivity (4.0 V/mm) and linear range (2.0 mm) ensure repeatable calibration traceability per ISO 10816 and API 670.

Detailed Specifications

Operational Capabilities

This probe monitors radial vibration, axial position, and differential expansion on centrifugal compressors, steam turbines, and large electric motors. In Oil & Gas, it operates continuously in offshore compressor trains (API RP 14C Zone 2 environments), supported by G3 conformal coating per IPC-CC-830B. In Power Generation, units meet SIL 2 requirements per IEC 61508 when paired with 3500/22M monitors. Hot-swap capability allows field replacement without rack power-down in Experion PKS Distributed Control Systems. Aerospace test stands use its thermal stability (±0.05% FS/°C drift) for transient rotor dynamics validation. MTBF exceeds 120,000 hours under rated load per Bently Nevada reliability testing protocol Rev. 9.1.

Technical FAQ

Q1: Does this probe support backward compatibility with legacy 3300 Series monitors (e.g., 3300/20, 3300/25)?

A: Yes. The 330708-00-20-50-02-00 maintains full electrical and mechanical compatibility with all 3300-series monitors released after 2003. It uses the same 3300 XL cable interface, 10–50 VDC excitation range, and standard −2 to −18 VDC output scaling. No firmware update is required on 3300/20 or 3300/25 racks. Calibration coefficients remain identical to 3300 XL 11 mm probes shipped since 2007.

Q2: How do I verify correct probe-to-monitor channel matching during installation on a 3500/42M rack?

A: Confirm probe part number matches the channel’s configured sensor type in Monitor Configuration Software (MCS) v6.2+. Use the 3500 Rack Diagnostics menu to validate loop resistance (standard: 4.5–6.5 Ω at 25 °C) and DC bias voltage (−12.0 ± 0.2 VDC at monitor output). Cross-check gap voltage: at 1.0 mm nominal gap, expect −10.0 ± 0.1 VDC output. Deviations >±0.3 VDC indicate mismatched sensitivity setting, damaged cable shield, or grounding fault on the 3300 XL extension cable.

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SEO Title: 330708-00-20-50-02-00 | Bently Nevada | 3300 XL 11 mm Probe

Meta Description: Genuine Bently Nevada 330708-00-20-50-02-00 3300 XL 11 mm proximity probe. In stock. 2.0 mm linear range, −40 to +125°C, 4.0 V/mm sensitivity, G3 coated.