Product Core Brief
- Model: 330851-02-000-070-50-01-05
- Brand: Bently Nevada
- Series: 3300 XL 25 mm Proximity Transducer System
- Core Function: 25 mm eddy-current proximity probe for differential expansion, axial/thrust position, and large-range displacement measurement when paired with a compatible 3300 XL 25 mm extension cable and proximitor.
- Product Type: 3300 XL 25 mm Probe
- Key Specs: 25 mm probe | 7.0 m cable | 1-1/2 in NPT | ClickLoc | multi-license approval
- Condition: New Original / New Surplus
Product Introduction
The Bently Nevada 330851-02-000-070-50-01-05 is a 3300 XL 25 mm proximity probe designed for large-range displacement measurement on rotating machinery. With a 12.7 mm (500 mil) linear range and approximately 0.787 V/mm (20 mV/mil) sensitivity, it is primarily used for differential expansion and axial/thrust position monitoring on medium to large steam turbine-generators.
This variant features a 7.0 m integrated probe cable (code 070), 1-1/2 in NPT mounting thread (code 02), ClickLoc connector (code 01), and multi-license agency approval (code 05). The 3300 XL 25 mm system is backward compatible with legacy 7200 25 mm and 25 mm DE systems, allowing upgrades without monitor reconfiguration. The exact mechanical configuration—such as thread length, unthreaded length, and cable exit orientation—must be confirmed from the physical label before installation.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Bently Nevada |
| Part Number | 330851-02-000-070-50-01-05 |
| Product Family | 3300 XL 25 mm Proximity Transducer System |
| Probe Diameter | 25 mm |
| Probe Cable Length | 7.0 m (code 070) |
| Mounting Thread | 1-1/2 in NPT (code 02) |
| Connector | ClickLoc (code 01) |
| Agency Approval | 05 – Multi-License Approval |
| Linear Range | 12.7 mm (500 mils) typical |
| Sensitivity | 0.787 V/mm (20 mV/mil) typical |
| System Power | −17.5 to −26 Vdc via proximitor |
| Frequency Response | 0 to 10 kHz typical (system-dependent) |
| Compatible Proximitor | 3300 XL 25 mm proximitor (verify system length) |
| Compatible Monitor | 3500/40M, 3500/42M, 3500/44M, 3500/25, 1900/65A, etc. |
Key Selling Points & Differentiators
- 12.7 mm linear range. The largest linear range in the 3300 XL family, essential for differential expansion measurement on large steam turbines.
- 7.0 m probe cable. Longer integrated cable reduces the required extension cable length, simplifying routing in large turbine installations.
- 1-1/2 in NPT thread. Matches standard DE probe mounting holes on turbine casings—critical for direct replacement without adapter fittings.
- ClickLoc connector. Tool-assisted, lockable coaxial connection that resists vibration loosening.
- Multi-license approval. The “05” code supports installations requiring certified agency compliance, subject to label verification.
- Backward compatible. Replaces legacy 7200 25 mm and 25 mm DE probes without monitor reconfiguration.
Quality Transparency SOP
- Part number verification. We confirm the label reads 330851-02-000-070-50-01-05 and matches the 3300 XL 25 mm probe family.
- Cable and connector inspection. The 7.0 m cable jacket, ClickLoc connector, and probe tip are checked for cracks, corrosion, or pin damage.
- Continuity and insulation check. Using a Fluke multimeter, we verify center conductor continuity and shield integrity from probe end to connector.
- Thread and tip inspection. The 1-1/2 in NPT threads and sensing face are checked for damage, galling, or contamination.
- ESD-safe packing. The probe is coiled to the recommended bend radius, sealed in an anti-static bag, and foam-packed to prevent connector stress.
Technical Risk Avoidance
❗ Confirm total system length before installation. This probe has a 7.0 m cable. The extension cable length must be selected so that probe cable + extension cable equals the proximitor system length—commonly 9.0 m for 25 mm systems. Verify the proximitor calibration matches the total length.
❗ Confirm mechanical configuration before installation. The 330851 family can be configured for different mounting arrangements. Verify the thread length, unthreaded length, and cable exit orientation against the physical label and your bracket geometry.
❗ Verify proximitor compatibility. The probe must be paired with a 3300 XL 25 mm proximitor calibrated for AISI 4140 steel and the correct system length. Using an 8 mm proximitor will produce incorrect sensitivity and range.
❗ Confirm the approval drawing for hazardous areas. The “05” code means multi-license approval, but the exact installation requirements—such as temperature class, IP rating, and voltage limits—must be verified against the physical label before commissioning in Zone 2 / Division 2 areas.
❗ Do not cut, splice, or repair the cable. The 3300 XL probe cable has defined impedance and shielding characteristics. Any modification can degrade signal integrity and measurement accuracy.
❗ Verify target material calibration. This probe system is factory calibrated for AISI 4140 steel. If the measured target is made from a different material, sensitivity and linear range may change.
Buyer’s FAQ
Is this a complete sensor system? No. This is the 25 mm probe only. A complete measurement channel also requires a compatible 3300 XL 25 mm extension cable and 3300 XL 25 mm proximitor.
Can I replace a 330851-02-000-060-50-01-05 with this? Not without checking cable length. The -060- variant has a 6.0 m probe cable, while this unit is 7.0 m. Changing cable length affects total system length and may require a different extension cable or proximitor recalibration.
Can I replace a 330851-02-000-070-50-00-05 with this? Electrically they are similar. The difference is the connector code: -00- may indicate a different connector style, while -01- is ClickLoc. Confirm the connector type matches your existing extension cable.
Can I use this with a 330180 8 mm proximitor? No. The 330180 is calibrated for 8 mm probes with 200 mV/mil sensitivity. The 330851 25 mm probe outputs 20 mV/mil and requires a 3300 XL 25 mm proximitor.
Does this include the extension cable and proximitor? No. Unless explicitly stated, this listing covers the probe only.
Is this genuine Bently Nevada? Yes. We sell genuine surplus inventory. The part number is verified against the physical label before dispatch.
What warranty applies? Standard 12-month warranty against DOA and functional defects. Mechanical damage from incorrect installation, thread mismatch, or chemical exposure is not covered.
