Product Core Brief

• Model: 330980-71-05
• Brand: Bently Nevada
• Series: 3300 XL NSv
• Core Function: Conditions raw eddy-current signals from proximity probes into standardized vibration and position data for monitoring systems.
• Product Type: Proximity Transducer (Proximitor) Sensor
• Key Specs: 5-Meter System | 200 mV/mil Sensitivity | DIN Rail / Panel Mount
• Condition: New Surplus / Original OEM

Bently Nevada 330980-71-05

Key Technical Specifications

• Manufacturer: Bently Nevada
• Part Number: 330980-71-05
• Product Category: 3300 XL NSv Proximitor Sensor
• System Length: 5 Meters (Probe + Extension Cable)
• Sensitivity: 7.87 mV/µm (200 mV/mil)
• Supply Voltage: -24 VDC
• Frequency Response: 0 to 10 kHz
• Linear Range: 1.5 mm (approx. 60 mils)
• Max Cable Length to Monitor: 305 meters
• Operating Temp Range: -55°C to +105°C
• Compliance: API 670 / CE / CSA / ATEX / IECEx

Product Introduction (No Fluff)

The 330980-71-05 is a complete 5-meter proximity transducer system designed for space-constrained applications on centrifugal compressors, refrigeration units, and process gas machinery. It integrates the eddy-current probe, extension cable, and signal-conditioning proximitors into a single, matched assembly to ensure absolute calibration integrity.

Sourcing this exact OEM replacement part prevents false trips and data loss caused by impedance mismatches in mixed-component systems. Keeping verified new surplus stock on hand drastically reduces unplanned downtime when legacy proximitors fail or when expanding monitoring coverage on critical rotating equipment.

QA & Testing SOP (Dynamic & Transparent)

Proximity transducers demand absolute signal fidelity. Every 330980-71-05 undergoes an inbound anti-counterfeit inspection, verifying Bently Nevada laser etching, tip epoxy finish, and factory labels. Next, we perform a DC resistance check and insulation impedance test (>2 MΩ) to rule out internal shorts or moisture ingress. We then verify the sensitivity curve using a calibrated TK-3E oscillator and target simulator to confirm the 200 mV/mil output is within tolerance. Finally, a visual inspection of the tip face ensures no scratches or oxidation. All units ship in anti-static shielding with a printed QA test report.

Installation Pitfalls & Guide (Engineer to Engineer)

❗ System Length Integrity: The “71-05” designates a 5-meter total system length. Never attempt to add additional extension cables to this assembly. Adding length changes the electrical impedance, causing severe scaling errors and non-linear readings. If you need a longer run, you must use a 7-meter system (e.g., 330980-71-07) instead.

❗ Gap Voltage Target: For an 8mm probe with 200 mV/mil sensitivity, set the static gap voltage to -10.0 VDC ± 0.2 VDC (or the specific midpoint listed on the calibration sheet). This centers the probe in its 1.5mm linear range, allowing symmetric positive/negative vibration swing. Always use the proximitors’ voltage readback, never mechanical measurement alone.

❗ Ground Loops & Shielding: The proximitors housing provides the proper shield ground point. Ensure the mounting bracket is isolated from machine ground if necessary. Grounding the shield at both the probe bracket and the proximitors creates a ground loop that injects 50/60 Hz hum directly into your vibration signal.

❗ Mounting Options: This proximitors supports both DIN rail and traditional 4-hole panel mounting. Both options provide electrical isolation, so no separate isolation plate is required. Ensure adequate clearance for the rear BNC connector and wiring bend radius.

Replacement Protocol:

1. Pre-Install: Lock out the proximitors power (-24 VDC). Verify 0 VDC at the input terminals. Inspect the mounting hole threads for debris.
2. Removal: Disconnect the BNC output and power cables. Unscrew the old proximitors from the bracket or DIN rail.
3. Install: Mount the new 330980-71-05. Route the integrated probe cable away from high-voltage lines. Connect the BNC to the 3500/40M or 3500/42M monitor.
4. Power-on Test: Restore -24 VDC power. Monitor the gap voltage on the front panel or DMM. Adjust the probe depth until -10.0 VDC is achieved. Lock the jam nut while holding the probe body to prevent rotation.

Bently Nevada 330980-71-05

Technical FAQ

Is this an exact drop-in replacement for my older 330980-50-00?
Yes, provided your existing system is also a 5-meter, 200 mV/mil configuration. The 330980-71-05 is an enhanced NSv version with improved RFI/EMI immunity and CE certification. It maintains complete backward compatibility with existing 3500 racks and 3300 XL probes.

Why is this listed as “New Surplus” instead of factory-new?
This is genuine Bently Nevada stock that was never deployed on a turbine or compressor. It has been stored in climate-controlled inventory rather than exposed to oil mist, steam, and vibration. You receive the exact same calibration stability and lifespan as a factory-fresh unit, typically at a significantly lower cost and without the 12-week lead time.

Can I hot-swap this proximitors while the monitor is powered?
Technically yes, but don’t. Disconnecting the BNC under power can cause a transient voltage spike that may damage the monitor module’s input stage. It takes 30 seconds to power down the channel. Do it safely to protect your expensive 3500/40M or 3500/42M module.

What is the warranty coverage on this part?
We provide a standard 12-month functional warranty. If the proximitors fails open, shorted, or drifts out of calibration under normal operating conditions within that window, we replace it. Our QA testing proves the unit met sensitivity specs before it left our bench.

My vibration readings are noisy. Is this proximitors bad?
Not necessarily. Before replacing the 330980-71-05, check the BNC connection for tightness. Verify the gap voltage is stable at -10 VDC. Noise is often caused by a ground loop (shield grounded at both ends), EMI from a nearby VFD, or a failing probe tip. Only replace the proximitors if electrical tests confirm an internal oscillator or amplifier fault.