Product Introduction
The Bently Nevada 991-06-50-02-00 is a specialized Probe Vibration Transmitter designed for axial thrust measurement in rotating machinery. As a drop-in replacement or upgrade for older 3300 series systems, this transmitter integrates seamlessly with existing Bently Nevada 3300 NSv proximity probes. Its 4-20 mA output and DIN rail mount simplify installation in control cabinets, making it a reliable choice for turbine and compressor monitoring.
Technical Specifications
Key specifications from the product data include:
-
Output Signal: 4-20 mAdc over specified full-scale range in 2-wire configuration
-
Power Input: Requires +12 to +35 Vdc at the transmitter terminal
-
Linear Range: 0.25 to 1.65 mm for Prox Output; suitable for 0.6-0-0.6 mm or 25-0-25 mils current loop linear ranges
-
Loop Accuracy: Within ±1.5% over specified full scale (typical) measured from TEST signal to voltage across a 250 Ω loop resistance
-
Maximum Loop Resistance: 1,000 Ω including cable at 35 Vdc
-
Current Limiting: 23 mA typical
-
Operating Temperature: -35°C to +85°C
-
Weight: 0.43 kg (0.9 lbm)
The Bently Nevada 991-06-50-02-00 also features a Not OK/Signal Defeat function, dropping the output below 3.6 mA within 100 µs upon a fault condition, with recovery in 0.1 seconds.
Industry Applications
Ideal for axial position monitoring in steam turbines, centrifugal compressors, and large motors, this transmitter provides accurate thrust bearing wear detection. Its fast fault response protects critical machinery from catastrophic damage. The 0.6-0-0.6 mm full-scale option is well-suited for common thrust measurement ranges in power generation and petrochemical plants.
Installation & Setup Guidance
Mount the Bently Nevada 991-06-50-02-00 on a standard DIN rail. Connect a single 3300 NSv proximity probe and extension cable to the input. Wire the 2-wire loop to a 4-20 mA receiver, ensuring that the loop resistance does not exceed 1,000 Ω at 35 Vdc. Use the non-interacting zero and span adjustments for calibration. The transmitter is designed for axial (thrust) measurement; position the probe accordingly.
Maintenance & Reliability
With no moving parts and a robust sealed enclosure, the transmitter requires minimal maintenance. Regularly inspect the probe and cable for wear. The operating temperature range of -35°C to +85°C allows use in harsh environments. The signal defeat logic ensures fail-safe operation, reducing unplanned downtime. Periodic verification of loop accuracy (within ±1.5%) extends reliable service life.
Selection Guide & Purchasing Advice
Before purchasing, verify your system requirements: confirm the probe type (3300 NSv), full-scale option (06: 0.6-0-0.6 mm), system length (50: 5.0 meters), mounting (02: bulkhead screws), and agency approval (00: not required). This unit is a direct replacement for earlier 991-series transmitters. For a reliable supply of genuine Bently Nevada 991-06-50-02-00 modules, contact ubest101. Ensure you have the necessary loop power supply (+12 to +35 Vdc) and a compatible 4-20 mA input card.