990-04-50-02-CN Vibration Transmitter Overview
When unplanned downtime threatens your rotating machinery, the 990-04-50-02-CN from Bently Nevada delivers a dependable vibration monitoring solution. This 990 series transmitter accepts one non-contacting 3300 NSv proximity probe and extension cable, converting dynamic vibration into a standard 4-20 mA signal. Designed for continuous operation, it helps you detect developing faults early, reducing repair costs and production losses.
With a full-scale range of 0-4 mils pp (0-100 μm pp), the 990-04-50-02-CN provides precise measurement for applications requiring tight tolerance monitoring. Its robust construction and country-specific approvals (CN) make it suitable for global installations. By integrating this transmitter into your condition monitoring strategy, you gain actionable insight into machine health without complex setup.
Key Features and Technical Specifications
The 990-04-50-02-CN is engineered for accuracy and reliability. Below are the critical specifications that define its performance:
- 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.
- Accuracy: Within ±1.5% over specified full-scale range (from TEST signal to voltage across 250 Ω loop resistance).
- 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.
- Probe Gap: Must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from target.
- NOT OK/Signal Defeat: Output goes to less than 3.6 mA within 100 µs after a Not OK condition; restored within 2-3 seconds after removal.
- Zero and Span: Non-interacting external adjustments.
- Weight: 0.43 kg (0.9 lbm).
These specs translate directly to cost efficiency. The ±1.5% accuracy reduces false alarms, minimizing unnecessary maintenance dispatches. The 23 mA current limiting protects the loop, extending component life and reducing replacement costs. The fast NOT OK response (<3.6 mA within 100 µs) ensures safety systems react quickly, preventing catastrophic failures.
Installation and Setup
Proper installation is key to maximizing the 990-04-50-02-CN's performance. The transmitter mounts via bulkhead screws (Mounting Option 02). The system length option is 5.0 metres (16.4 feet), which defines the cable run from the probe to the transmitter. Ensure the probe gap is set between 0.5 and 1.75 mm (20 and 55 mils) from the target to achieve full-scale range. The leadwire length for the Proximitor Sensor Output (BNC connector) must not exceed 3 meters (10 feet).
Power the transmitter with +12 to +35 Vdc at the terminal. The maximum loop resistance is 1,000 Ω including cable at 35 Vdc, so verify your wiring resistance to stay within limits. Non-interacting external zero and span adjustments simplify calibration, reducing setup time and labor costs. Always follow the manufacturer's manual for detailed wiring and configuration.
Maintenance and Reliability
Regular inspection of the 990-04-50-02-CN ensures long-term reliability. Periodically verify the probe gap and cable connections, as vibration or thermal cycling can loosen fittings. Check the loop current to confirm it stays within the 4-20 mA range and that the NOT OK signal responds correctly. Since the transmitter is designed for continuous operation, minimal maintenance is required—reducing lifecycle costs.
Environmental factors such as temperature and humidity can affect performance. The transmitter is rated for NonHazardous, Zone 2 or Div 2 hazardous area locations (Power Supply: 28 V). Ensure the installation environment meets these ratings to avoid premature failure. By following a simple inspection schedule, you extend the service life of the unit and avoid costly replacements.
Compatibility and Integration
The 990-04-50-02-CN integrates seamlessly with existing Bently Nevada monitoring systems. It accepts a 3300 NSv proximity probe, a standard in the industry. The 4-20 mA output is compatible with most PLCs, DCSs, and SCADA systems, making it easy to retrofit into current setups. The 2-wire configuration reduces wiring complexity, lowering installation costs.
For hazardous area installations, the transmitter supports Zone 2 or Div 2 locations with a 28 V power supply. This compatibility ensures you can deploy the 990-04-50-02-CN across various plant environments without additional isolation hardware. Always verify system compatibility with your specific control system before ordering.
Availability and Support
The 990-04-50-02-CN is available through AutoDCSTech, your trusted industrial automation parts supplier. We stock genuine Bently Nevada products to ensure reliability and performance. Contact our team for pricing, availability, and technical support. We are ready to help you implement a cost-effective vibration monitoring solution.
