Introduction to the 990-05-50-03-CN
The Bently Nevada 990-05-50-03-CN is a 990 Vibration Transmitter designed for continuous machinery protection. Over the years, industrial plants have shifted from manual vibration checks to continuous electronic monitoring. This transmitter meets that need by converting proximity probe signals into a standard 4-20 mA output. It accepts one non-contacting 3300 NSv Proximity Probe and extension cable. The 990-05-50-03-CN is made in the U.S.A. and carries country-specific CN approvals.
Key Features and Technical Specifications
The 990-05-50-03-CN offers a full-scale option of 0-5 mils pp (0-125 μm pp). This range suits many rotating machinery applications. The system length option is 0-5.0 metres (16.4 feet), giving flexibility in installation. Mounting is via DIN clips and screws, simplifying panel integration.
- Input: Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.
- Power: Requires +12 to +35 Vdc input at the transmitter terminal.
- Output: 4 to 20 mAdc over specified full-scale range in 2-wire configuration.
- Loop accuracy: Within ±1.5% over specified full-scale range.
- Maximum loop resistance: 1,000 Ω including cable at 35 Vdc.
- Current limiting: 23 mA typical.
- Frequency response: 5 Hz to 6,000 Hz +0, 3 dB.
- Minimum target size: 9.5 mm (0.375 in) diameter.
- Leadwire length: Maximum 3 meters (10 feet) for Proximitor Sensor Output (BNC connector).
These specifications ensure reliable vibration monitoring in demanding industrial environments.
Installation and Setup
Proper installation is critical for accurate vibration measurement. The probe must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from the target to ensure full-scale range. The transmitter requires +12 to +35 Vdc power at its terminal. Use the DIN clips and screws for secure mounting. Follow the manufacturer's manual for wiring and configuration.
Maintenance and Reliability
Regular inspection of the probe and cable is recommended. Verify that the probe gap remains within the specified range. Check the loop resistance to stay within 1,000 Ω. The transmitter's non-interacting external zero and span adjustments simplify calibration. For safety-rated equipment, always follow the manufacturer's safety manual.
Compatibility and Integration
The 990-05-50-03-CN integrates with Bently Nevada 3300 NSv proximity probes. It provides a 4-20 mA signal that can interface with PLCs, DCS, and SCADA systems. The 2-wire configuration reduces wiring complexity. The transmitter is suitable for non-hazardous, Zone 2, or Div 2 hazardous area locations with a 28 V power supply.
Troubleshooting and Common Issues
If the signal output goes below 3.6 mA within 100 µs, a Not OK condition is indicated. The output restores within 2-3 seconds after the condition is removed. Verify probe gap and cable connections first. Check power supply voltage and loop resistance. Refer to the official Bently Nevada documentation for detailed diagnostics.
Product Support and Availability
The 990-05-50-03-CN is available from AutoDCSTech. Please verify current lifecycle status and availability with AutoDCSTech before ordering. Contact our team for technical support and pricing.
