Product Overview: Bently Nevada 990-08-50-02-00 990 Vibration Transmitter
When unplanned downtime threatens production, the Bently Nevada 990-08-50-02-00 990 Vibration Transmitter delivers reliable machinery protection. Designed for continuous vibration monitoring, this industrial automation module accepts a single non-contacting 3300 NSv proximity probe and converts dynamic shaft motion into a proportional 4-20 mA signal. Its fast-acting NOT OK/signal defeat circuit forces the output below 3.6 mA within 100 µs of a fault condition, preventing erroneous readings that could trigger false trips or mask real issues.
Key Technical Specifications
All values are taken directly from the Bently Nevada 990-08-50-02-00 datasheet.
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Input: Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.
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Power Supply: +12 to +35 Vdc input at the transmitter terminal.
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4 to 20 mA Output: Over specified full-scale range in 2-wire configuration.
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Loop Accuracy: Within ±1.5% over full-scale range (referenced from TEST signal to voltage across 250 Ω loop).
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Maximum Loop Resistance: 1,000 Ω including cable at 35 Vdc.
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Current Limiting: 23 mA typical.
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Frequency Response: 5 Hz to 6,000 Hz +0, -3 dB.
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Probe Gap: 0.5 to 1.75 mm (20 to 55 mils) from target.
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Minimum Target Size: 9.5 mm (0.375 in) diameter.
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Weight: 0.43 kg (0.9 lbm).
Real-World Applications
The Bently Nevada 990-08-50-02-00 excels in rotating machinery protection: steam turbines, centrifugal compressors, and large pumps. Its 0-8 mils pp (0-200 µm pp) full-scale range suits sleeve-bearing machines with moderate vibration levels. The system length option of 5.0 meters allows the transmitter to be mounted remotely from the probe, simplifying wiring in crowded panels. In hazardous environments (Zone 2 or Div 2), the transmitter operates safely with a 28 V power supply.
Installation & Setup Guide
Mount the Bently Nevada 990-08-50-02-00 using the bulkhead screw option (Mounting Option 02). Proper probe gap is critical: between 0.5 and 1.75 mm from the target. Use the non-interacting zero and span adjustments for calibration. Ensure loop resistance does not exceed 1,000 Ω, including cable, to maintain accuracy. For the Proximitor sensor output, keep the BNC cable under 3 meters (10 feet) to preserve signal integrity.
Maintenance & Reliability
The Bently Nevada 990-08-50-02-00 requires minimal routine care due to its solid-state design. Check the probe gap during scheduled outages to confirm it remains within the specified range. The current limiting (23 mA typical) protects against short circuits. The signal defeat feature automatically indicates a fault, reducing diagnostic time. In dusty or corrosive environments, keep the transmitter enclosure clean and ensure ventilation around the terminal block.
Selection Guide & Purchasing Advice
Before ordering, verify that the probe and cable match the 3300 NSv series. The 990-08-50-02-00 includes the transmitter only; probe extensions are sold separately. Contact ubest101 for bulk pricing or technical questions. PLC Source PRO ensures original Bently Nevada parts with documented traceability.