Description
The Bently Nevada 330980-71-CN is a high-performance Proximitor sensor belonging to the 3300 XL NSv (Narrow Side View) proximity transducer series. It operates as the signal-conditioning core of a non-contact eddy-current measurement system, paired with a matching 3300 NSv probe and extension cable. The NSv architecture is engineered specifically for applications with small installation targets or restricted physical clearances, such as small centrifugal air compressors, refrigeration compressors, and process gas compressors. It delivers precise static (gap) and dynamic (vibration) measurements of shaft displacement.
Commercial Availability & Terms
- Condition: New Original (Factory Sealed Surplus)
- Warranty: 12-Month Comprehensive Industrial Warranty
- Availability: In Stock
- Standard Lead Time: Ships within 1–3 business days via worldwide express couriers
- Pricing Note: Price varies depending on market demand and regulatory certification updates. Contact our technical engineering sales division for a formal, time-bound quotation.
Part Number Configuration Breakdown
The alphanumeric suffix code 330980-71-CN defines the exact mechanical mount, system tuning constraints, and regional hazardous area compliance guidelines:
- 330980 (Base Model): 3300 XL NSv Proximitor Sensor platform featuring advanced RFI/EMI immunity.
- -71 (Total Length and Mounting Option): Configured for a 7.0 meter (23.0 feet) total electrical system length; designed with an integrated, electrically isolated DIN-rail mounting base.
- -CN (Agency Approval Option): Country-specific certification profile, adding localized Chinese NEPSI hazardous area markings alongside baseline ATEX and IECEx explosion-proof ratings for installation in Zone 0, Zone 1, and Zone 2 environments.
Technical Specifications
| Parameter | Value / Specification |
| Scale Factor Baseline | 7.87 V/mm (200 mV/mil) standard linear target response |
| Linear Range Span | Starts at 0.25 mm (10 mils) up to 1.25 mm (50 mils) from probe face |
| Excitation Power Input | -17.5 V DC to -26 V DC (maximum current draw 12 mA) |
| Output Impedance | 50 \Omega nominal characteristic output impedance |
| Signal Noise Floor | Highly immune to radio frequency interference; meets CE mark without shielded conduit |
| Housing Construction | Cast A380 aluminum body with gold-plated brass coaxial connectors |
| Operating Temperature | −35 to +85 °C (−31 to +185 °F) continuous ambient range |
| Physical Footprint | 81.3 mm \times 61.0 mm \times 63.5 mm (3.2 in \times 2.4 in \times 2.5 in) |
Field Integration & Architectural Constraints
When deploying the 330980-71-CN in an active monitoring loop, several rigid field constraints must be enforced:
- System Length Synchronization: The internal oscillator and demodulator circuitry are precisely tuned to a specific capacitive and inductive profile. Because this unit is a
-71option (7.0 meter system length), the sum of the physical probe length and the physical extension cable length must exactly equal 7.0 meters (e.g., a 1.0 meter probe mated to a 6.0 meter extension cable). Mismatching components to a 5.0 meter or 9.0 meter asset pool will lead to catastrophic calibration deviations and invalid data tracking. - Side-view Clearance Constraints: The “NSv” designation indicates a tighter electromagnetic field cone than standard 8mm probes. While it requires less cross-sectional counterbore clearance (reducing the required side gap to prevent side-wall interference), engineers must still verify the installation geometry against the OEM datasheet when mounting the probe near structural machine shoulders or bearing housings.
- Power Delivery Inversion: Like all Bently Nevada proximity systems, this sensor utilizes a negative voltage rail infrastructure. The terminal connections are labeled
VT(Voltage Transmitter / Power),OUT(Signal Output), andCOM(Common). Reversing the polarity or shortingVTto a positive 24 V DC bus will blow the internal protection diodes, causing irreversible module failure.
Frequently Asked Questions
Why choose an NSv Proximitor sensor over a standard 3300 XL 8mm system?
The standard 3300 XL 8mm probe requires a large physical cross-sectional area to maintain its linear field. If a machine has narrow target tracks or deep, narrow counterbores, a standard probe will see the side walls instead of the shaft, causing cross-talk and baseline distortion. The 330980 NSv series operates on a higher frequency envelope and specialized tip geometry, allowing it to accurately read targets with highly confined cross-sectional side clearance.
Does the integrated DIN-rail base require separate insulation plates?
No. The mounting base engineered into the 330980 housing provides absolute electrical isolation from the DIN rail or back panel. This eliminates the older practice of using separate phenolic or plastic isolation plates to isolate the sensor casing from earth ground, mitigating common-mode ground noise loops.
How do I troubleshoot a “Sensor Limit” fault on the machinery protection monitor?
Connect a digital multimeter between the OUT and COM terminals. With the machine at rest, measure the static DC voltage (gap voltage). Under normal operations, the voltage should read within a stable range between -4.0 V DC and -14 V DC. If the reading is fixed at approximately -1.0 V DC or lower, the probe is either contacting the shaft or the coaxial cable is shorted. A reading hovering at the supply rail voltage (-24 V DC) indicates an open-circuit path across the extension cable or a disconnected connector.
