bently-nevada-330130-045-02-05-field-service

Description

Hard-Numbers: Technical Specifications

• Probe Tip Diameter: 8 mm (0.315 in.)
• Linear Range: 2.0 mm (80 mils) from probe tip (typical gap range: 0.25mm to 2.25mm)
• Probe Body Diameter: 8 mm (0.315 in.) / 5/8-18 UNF-2A threaded mounting
• Probe Body Material: 316L stainless steel (probe housing), Inconel X-750 probe tip
• Probe Length: 45 mm (1.77 in.) from mounting face to tip
• Thread Length: 12.7 mm (0.5 in.)
• Cable Configuration:
  • Probe end: Fixed 0.5m integral cable
  • Extension cable: Not specified (typically sold as complete probe assembly; extension added separately if needed)
  • Total System Length (from probe to proximitor): 5m (16.4 ft) as indicated by “-045-” in model number
• Cable Type: 3300 XL series, high-flex, stainless steel overbraid shield, PTFE insulation
• Probe-to-Proximitor Compatibility: Requires 3300 XL Proximitor oscillator/demodulator (e.g., 330180-50-05)
• Supply Voltage: -24 VDC ±10% from Proximitor
• Input Current: Typically 12-15 mA at -24 VDC
• Output Signal:
  • Gap Voltage: -2.0 to -18.0 VDC linear range (typical)
  • Sensitivity: 7.87 V/mm (200 mV/mil) for 3300 XL system
• Frequency Response: DC to 10 kHz (within ±3dB)
• Temperature Range:
  • Operating: -51°C to +177°C (-60°F to +350°F) with 3300 XL Proximitor
  • Probe only: -51°C to +177°C (-60°F to +350°F)
  • Cable: -40°C to +105°C (-40°F to +221°F)
• Pressure Rating: Up to 350 bar (5,000 psi) with proper mechanical seal
• Vibration Resistance: Up to 500 g shock, 50 g continuous vibration
• Immunity:
  • EMI: >100 V/m radiated immunity (3300 XL improvement)
  • Ground Loop: Common mode rejection >80 dB at 50/60 Hz
• Compliance:
  • ATEX/IECEx: II 2G Ex ia IIC T4 Ga/T4 Gb (with suitable barriers)
  • UL: Class I, Div 2, Groups A, B, C, D, T4
  • CE: EN 60079 series (with barriers)
• Dimensions:
  • Probe: 45 mm length × 8 mm diameter
  • Cable: 5m total system length
• Weight: 0.35 kg (0.77 lb) probe + cable assembly

Bently 330105-02-12-10-02-CN

The Real-World Problem It Solves

• Steam turbine generator sets in power plants, monitoring radial vibration on all journal bearings and axial thrust position
• Centrifugal compressors in gas processing plants, tracking shaft eccentricity and surge protection
• Boiler feed pumps and large motors in refineries, measuring bearing vibration and shaft position
• Hydro turbines in hydroelectric plants, monitoring guide bearing vibration and runner position
• Gearboxes and high-speed couplings in heavy industrial applications, detecting misalignment and wear

Hardware Architecture & Under-the-Hood Logic

1. Proximitor Excitation: The 3300 XL Proximitor generates a high-frequency RF signal (typically 1.5 MHz) that travels through the probe cable to the probe tip coil.
2. Inductive Sensing: The probe tip coil creates an electromagnetic field. When conductive shaft material enters this field (within the linear range), eddy currents are induced in the shaft surface, reducing the coil’s inductance.
3. Gap-to-Voltage Conversion: The Proximitor detects the change in coil inductance and converts it to a DC output voltage using synchronous demodulation. The relationship between gap and voltage is linear within the 2.0mm (80 mil) linear range.
4. Signal Characteristics:
   • Linear Range: From approximately 0.25mm to 2.25mm gap, output varies linearly from -2.0V to -18.0V (7.87 V/mm sensitivity)
   • Slope: 7.87 V/mm (200 mV/mil) for 3300 XL system
   • Null Point: Typically at 0.75mm to 1.25mm gap (varies by system configuration)
5. Cable Architecture: The probe’s integral 0.5m cable connects to an extension cable (if used), which then connects to the Proximitor. The 3300 XL system maintains tight capacitance tolerance (+/- 3% or better) to ensure consistent sensitivity across different cable lengths. The “-045-” designation indicates a 5m total system length from probe to Proximitor.
6. Shielding and Grounding: The cable has a stainless steel overbraid shield with a drain wire. The shield must be grounded at the Proximitor end only to prevent ground loops. The probe body is isolated from the cable shield (isolated tip construction) to minimize ground path interference.
7. Temperature Compensation: The 3300 XL system includes automatic temperature compensation in the Proximitor to minimize drift across the operating temperature range. The probe’s 316L stainless steel housing and Inconel tip provide excellent thermal stability.

Bently 330105-02-12-10-02-CN

Field Service Pitfalls: What Rookies Get Wrong

• Field Rule: For 3300 XL systems, target a gap voltage of approximately -9.0V to -10.0V at the shaft position where you’ll operate. This centers the vibration within the 2.0mm linear range. The older 3300 systems used -7.0V, but 3300 XL has different characteristics due to improved probe design. Always check the Proximitor’s calibration curve for your specific probe/cable combination.

• Field Rule: The 3300 XL system maintains tight capacitance tolerance, but you MUST recalibrate the monitor’s input scale when changing cable lengths. The 3500 monitor configuration software includes probe type and cable length parameters—update these and verify the scale factor with a mechanical calibration (target block or dial indicator) if precision is required. Sensitivity can vary ±2-3% between different cable lengths.

• Quick Fix: Ground the shield ONLY at the Proximitor end (at the terminal block). Leave the probe end floating (ungrounded). The 3300 XL cables have a stainless steel overbraid with a drain wire—connect the drain wire to the Proximitor’s chassis ground terminal. For hazardous areas, follow the barrier manufacturer’s grounding scheme, but still maintain single-point grounding where possible.

• Field Rule: Torque the 5/8-18 threaded probe to 4.5-6.8 N·m (40-60 in-lbs) maximum. Use a torque wrench for critical installations. Do NOT use pipe sealant or Teflon tape on the threads—these can affect electrical isolation. For high-vibration applications, consider a jam nut or locknut to prevent loosening, but don’t over-tighten.

• Field Rule: The linear range is strictly 2.0mm (80 mils) within the probe’s sensing zone. Position the probe tip so that at normal operating shaft position, you have approximately 1.25mm (50 mils) of gap, giving you ±0.5mm (±20 mils) of vibration travel before hitting non-linear regions. Monitor the gap voltage—anything outside -2V to -18V is outside the linear range.

• Field Rule: 3300 XL probes require a 3300 XL Proximitor (e.g., 330180-50-05). Older 3300 or 7200 Proximitors have different characteristics and are not interchangeable. The Proximitor model number is printed on the label—look for “330180” to confirm XL compatibility. Mismatched systems will work but with reduced accuracy and shifted linear range.

• Field Rule: Use the 3500 monitor’s mechanical runout compensation feature (slow roll compensation) to subtract mechanical imperfections from the vibration signal. Perform a slow roll (barring gear) at 50-100 RPM, record the runout vector, and configure the monitor to subtract this from running vibration. This is critical on older machines with worn bearing journals.

Commercial Availability & Pricing Note