Bently Nevada 3300 Series Modules - 330101-00-48-10-02-00

Technical Dossier

Product Details And Specifications

Bently Nevada 3300 Series Technical Notes

The Bently Nevada 3300 Series is one of the most widely deployed eddy-current proximity measurement systems in global heavy industry. Installed across petrochemical refineries, nuclear power stations, LNG terminals, steel mills, and rotating machinery platforms, the 3300 Series provides continuous, non-contact measurement of shaft radial vibration, axial position, differential expansion, and eccentricity. Its modular architecture — separating the probe, extension cable, and proximitor into discrete, field-replaceable components — has made it the de facto standard for turbomachinery protection systems operating under API 670 requirements.

The Evolution of 3300 Series Architecture

The 3300 Series was designed around the eddy-current measurement principle: a high-frequency oscillator drives a coil in the probe tip, and the resulting electromagnetic field interacts with the conductive target shaft. Changes in gap distance alter the field impedance, producing a voltage output linear to displacement. This analog signal chain — probe → extension cable → proximitor — has remained architecturally consistent across the series lifetime, which is both its strength (backward compatibility) and its procurement challenge (aging components, discontinued part numbers).

Early Generation (3300/5mm, 3300/8mm, 3300/11mm): Defined by probe tip diameter and gap range. The 5mm probe targets gaps of 0.25–2.25 mm; the 8mm probe covers 0.25–2.54 mm; the 11mm probe extends to 0.25–2.79 mm. These variants were designed for different shaft diameters and machine frame geometries.

Mid-Generation (3300 XL Series): Introduced extended temperature ratings and improved EMI shielding. The XL designation indicates compatibility with higher ambient temperature environments (up to 177°C at the probe tip), making them suitable for hot-section turbine applications.

Extension Cable Standardization: The 3300 Series uses armored coaxial extension cables in standard lengths of 1m, 2m, 3m, 5m, and 9m. Cable length directly affects the system scale factor (mV/mil or mV/mm), and mismatched cable lengths are a documented source of measurement error during maintenance replacement.

Proximitor Evolution: Early proximitors (3300/05, 3300/08, 3300/11) were panel-mount units. Later variants introduced DIN-rail mounting and dual-channel configurations. The proximitor contains the oscillator-demodulator circuit and outputs a DC voltage proportional to gap. It is the most failure-prone component in the signal chain due to internal oscillator drift over time.

Transition to 3500 Series: Bently Nevada introduced the 3500 Series rack-based monitoring system as the digital successor. The 3500 Series supports the same probe/cable hardware but replaces the analog proximitor with a digital I/O module, enabling integration with DCS/SCADA via Modbus, Profibus, and Ethernet. Facilities running 3300 Series proximitors that cannot justify a full 3500 upgrade often pursue a hybrid strategy: retaining 3300 probes and cables while upgrading the monitoring rack.

3300 Series Full Catalog & Functionalities (SKU List)

Proximity Probes (by tip diameter):

• 330101-00-48-10-02-00: 8mm proximity probe, 48-inch armored cable, standard temperature, 200 mV/mil scale factor, reverse mount configuration — the most common general-purpose radial vibration probe in the 3300 family.
• 330101-00-24-10-02-00: 8mm proximity probe, 24-inch integral cable, standard temperature, suitable for compact machine frames with limited cable routing space.
• 330101-00-36-10-02-00: 8mm proximity probe, 36-inch integral cable, standard temperature, intermediate cable length for mid-size turbine bearing housings.
• 330104-00-48-10-02-00: 8mm XL proximity probe, 48-inch cable, extended temperature rating to 177°C, designed for hot-section gas turbine and steam turbine applications.
• 330105-02-12-10-02-00: 5mm proximity probe, 12-inch integral cable, standard temperature, used in smaller rotating equipment where shaft diameter limits probe tip size.
• 330130-080-01-00: 11mm proximity probe, standard temperature, 80-inch cable, used for large-bore shaft applications in compressors and generators.

Extension Cables:

• 330130-045-01-00: 3300 Series extension cable, 45-inch (approx. 1.14m), armored coaxial, compatible with all 3300 8mm probes. Must be matched to proximitor calibration.
• 330130-080-00-00: 3300 Series extension cable, 80-inch, armored coaxial, standard for longer cable runs between bearing housing and junction box.
• 330130-045-00-00: 3300 Series extension cable, 45-inch, non-armored, for protected indoor installations.
• 330180-X1-05: 3300 Series extension cable assembly, 5-meter, with field-installable connectors, used in retrofit and replacement scenarios.

Proximitors / Signal Conditioners:

Accessories & Mounting Hardware:

• 21747-01: Probe mounting bracket, adjustable, stainless steel, compatible with 8mm and 11mm probe bodies. Standard for field installation on bearing housings.
• 02-262610-01: Proximitor mounting plate, panel-mount, for 3300/08 and 3300/11 units. Required for installations in older relay-logic panels without DIN rail.

Sourcing Hard-to-Find & Obsolete 3300 Series Parts

For facilities evaluating migration to the 3500 Series, DriveKNMS can supply both legacy 3300 components for interim maintenance and 3500 I/O modules for phased upgrade programs, allowing procurement teams to manage transition costs across multiple budget cycles.

Quality Control for the 3300 Series Range

The 3300 Series signal chain is sensitive to component-level degradation that does not always manifest as a hard failure. A proximitor with a drifted oscillator frequency will produce a shifted scale factor, causing the monitoring system to under-read or over-read vibration amplitude — a condition that can mask developing machinery faults or trigger false alarms. Standard continuity testing is insufficient to detect this failure mode.

DriveKNMS applies the following test protocol to all 3300 Series units prior to shipment:

• Proximitor oscillator frequency verification: Measured against OEM specification (typically 1.0 MHz ± 5% for 8mm systems). Units outside tolerance are rejected.
• Scale factor calibration check: Each proximitor is tested with a calibrated target at known gap distances (0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm) to verify output linearity and mV/mil accuracy.
• Bias voltage output test: Confirmed at –24 VDC ± 1V under load conditions.
• Probe coil impedance measurement: Verifies coil integrity and absence of internal shorts or open circuits in the probe tip assembly.
• Extension cable continuity and insulation resistance: Tested at 500 VDC to confirm cable jacket integrity and absence of moisture ingress — a common failure mode in armored cables installed in wet or chemically aggressive environments.
• System-level functional test: Where possible, probe, cable, and proximitor are tested as a matched set to verify end-to-end signal chain performance.

Q: How are RFQ terms confirmed?
A: Quantity, required condition, documentation needs, destination and sourcing route are confirmed during RFQ review before quotation.