Bently 990‑04‑50‑02‑00

Bently 990‑04‑50‑02‑00

Product Introduction: 990‑04‑50‑02‑00 belongs to 990‑series two‑wire vibration‑transmitter with integrated proximitor circuit. It is calibrated for NSv transducer‑system total electrical‑length 5 meters. Full‑scale shaft radial‑vibration measuring‑range equals 0‑0.25 mm peak‑to‑peak. It receives eddy‑current‑sensor signal from 3300 NSv proximity‑probe and matched 5‑meter total‑length extension‑cable assembly, converts shaft radial‑vibration amplitude into standard 4‑20 mA two‑wire loop‑output‑signal, directly sends measurement‑data to external DCS, PLC and plant‑SCADA‑systems. It realizes shaft‑vibration monitoring without needing rack‑mount separate proximitor hardware.

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Description

Bently 990‑04‑50‑02‑00

Technical Specifications:

  • Compatible Transducer‑System: 3300 NSv probe plus extension‑cable, total electrical‑length 5 meters
  • Measured Parameter: Shaft radial vibration peak‑to‑peak amplitude
  • Full‑Scale Measurement‑Range: 0‑0.25 mm peak‑to‑peak
  • Power‑Supply Mode: Two‑wire loop‑powered, +12 VDC ~ +35 VDC
  • Output Signal: 4‑20 mADC two‑wire loop
  • Loop‑Accuracy: ±1.5% full‑scale
  • Frequency‑Response: 5 Hz ~ 6000 Hz (-3 dB)
  • Diagnostic Terminal: Prox‑Out gap‑voltage output terminal available
  • Maximum Allowable Loop‑Resistance: 1000 Ω @35 VDC
  • Mounting Method: 35 mm DIN‑rail clip‑mount or panel screw‑mount installation
  • Operating Temperature: ‑40 °C ~ +85 °C
  • Relative Humidity: 0‑95% RH non‑condensing
  • Startup‑Inhibition Function: Output stays under fault‑level current within 2‑3 seconds after power‑on Functional Features:
  1. Integrated full proximitor conditioning‑circuit; NSv proximity‑probe system directly connects transmitter input terminals without external proximitor unit.
  2. Two‑wire loop‑power transmission, single‑pair cable implements power‑supply feeding and vibration‑signal transmission, reduces field‑wiring cost and complexity.
  3. On‑board zero‑point and span adjustable potentiometers support convenient on‑site calibration‑operation.
  4. Dedicated test‑input terminal supports loop‑function verification without real NSv‑sensor hardware‑connection.
  5. Built‑in sensor‑loop fault‑detection circuit; when probe open‑circuit, short‑circuit or cable‑fault appears, output locks to fixed NOT‑OK fault‑current level to avoid control‑system false‑alarm triggered by invalid vibration‑data.
  6. Prox‑Out diagnostic‑terminal outputs raw DC gap‑voltage value for on‑site probe‑cable fault‑diagnosis work.
  7. Fully potted sealed internal‑construction, performs stable operation under high‑humidity instrument‑cabinet environment. Application Scenarios: Radial‑shaft‑vibration monitoring for medium‑vibration‑range compressors, fans, pumps and motor‑sets; machinery‑upgrade‑retrofit‑projects without 3500‑rack TSI‑hardware; OEM‑complete‑machine supporting application; hazardous‑area field‑vibration‑signal‑conversion for DCS‑PLC‑system input. Performance Parameters: Amplitude linear‑error ≤±1.5% full‑scale; fault‑response‑time less than 200 ms; strong anti‑electromagnetic‑interference‑ability for industrial‑site environment; low temperature‑drift over full operating‑temperature‑range. Material Composition: Flame‑retardant potting compound; multi‑layer analog‑digital mixed‑signal printed‑circuit‑board; high‑precision signal‑conditioning chips; gold‑plated wiring‑terminals; flame‑retardant engineering‑plastic housing; metal DIN‑rail spring‑locking clip; silicone sealing gaskets. Structural Characteristics: Standard DIN‑rail rectangular housing dimension; front‑side wiring‑terminal‑block; sealed calibration‑potentiometer access window; rear spring‑loaded DIN‑rail locking clip; housing surface printed with model‑number, full‑scale vibration‑range and unique unit serial‑number. Working Principle: Internal high‑frequency‑excitation circuit sends high‑frequency AC excitation‑signal to connected NSv proximity‑probe coil. Rotating‑shaft radial‑vibration changes gap‑distance between probe tip and metal‑shaft‑target‑surface. Gap‑variation produces eddy‑current‑magnitude‑change on shaft‑surface, leads to probe‑coil‑impedance‑variation. Transmitter internal circuit processes impedance‑variation‑signal, computes real‑time peak‑to‑peak vibration‑amplitude value, converts measured‑value into 4‑20 mA loop‑current‑signal. Fault‑diagnosis circuit continuously monitors sensor‑loop operating‑status. Prox‑Out terminal outputs raw gap‑voltage for maintenance‑inspection purpose. Installation Requirements:
  8. Install transmitter onto standard 35 mm DIN‑rail inside instrument‑cabinet, confirm rear spring‑locking clip fully engaged.
  9. Strictly observe two‑wire loop‑polarity; AC‑voltage must never connect to loop‑power terminals.
  10. Total electrical‑length of NSv probe plus matched extension‑cable must keep exact 5‑meter value matching factory‑calibration setting.
  11. Separate NSv sensor‑cable and 4‑20 mA output‑cable routing‑path away from high‑power motor and inverter power‑cables.
  12. Complete zero‑point‑span calibration via test‑input terminal after installation‑wiring finishes. Usage Notes:
  13. Do not cut, splice or re‑solder NSv probe and matched extension‑cable assembly; modified electrical‑length invalidates factory‑calibration and measurement‑accuracy.
  14. Mark potentiometer position after finishing calibration; prohibit random adjustment during normal‑equipment‑running‑process.
  15. Must not exceed maximum allowable loop‑resistance‑value; excessive resistance will distort 4‑20 mA output‑signal.
  16. Periodically measure Prox‑Out gap‑voltage reading during equipment‑inspection‑cycle to identify connector‑loosening and cable‑aging hidden‑fault risk.

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