Bently Nevada 990-10-70-03-CN Vibration Transmitter Overview
When machine vibration threatens uptime, the 990-10-70-03-CN provides a direct path to actionable data. This Bently Nevada 990 Vibration Transmitter accepts one non-contacting 3300 NSv proximity probe and extension cable, converting shaft vibration into a standard 4-20 mA signal. Designed for continuous operation, it delivers accurate, real-time condition monitoring for rotating equipment.
With a full-scale range of 0-10 mils pp (0-250 μm pp), the transmitter covers typical vibration levels found in industrial machinery. The 7.0-meter (23.0 feet) system length option simplifies installation when the probe must be located away from the monitor. Mounting is flexible via DIN clips and screws, and the country-specific approval option (CN) ensures compliance with regional requirements.
Key Features and Technical Specifications
The 990-10-70-03-CN is engineered for precision and reliability. Its key specifications are detailed below:
- Input: Accepts 1 non-contacting 3300 NSv proximity probe and extension cable.
- Power: Requires +12 to +35 Vdc input at the transmitter terminal.
- Output: 4-20 mAdc over specified full-scale range in 2-wire configuration.
- Loop Accuracy: Within ±1.5% over specified full-scale range (from TEST signal input to voltage across a 250 Ω load).
- 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 drops to less than 3.6 mA within 100 µs after a Not OK condition; restored within 2-3 seconds after removal.
One distinctive feature is the fast Not OK signal defeat—the output drops below 3.6 mA within 100 µs, alerting control systems immediately to a fault. This rapid response helps prevent damage and reduces downtime.
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 system length option of 7.0 meters (23.0 feet) allows flexible placement of the transmitter relative to the probe.
Mounting is straightforward using the DIN clips and screws provided. The transmitter requires a +12 to +35 Vdc power supply at its terminal. For best results, follow the manufacturer's installation manual and verify the probe gap before energizing the loop.
Applications and Use Cases
The 990-10-70-03-CN is ideal for monitoring vibration on pumps, fans, motors, and other rotating machinery. Its 4-20 mA output integrates easily with PLCs, DCS, and SCADA systems. In predictive maintenance programs, the transmitter provides continuous data that helps identify bearing wear, unbalance, and misalignment early.
Because it accepts a 3300 NSv probe, it is well-suited for retrofitting existing Bently Nevada monitoring systems. The compact design and DIN mounting make it a practical choice for panel upgrades or new installations.
Maintenance and Reliability
Regular inspection of the probe and cable is recommended to ensure reliable operation. Check that the probe gap remains within the specified range and that the cable is not damaged. The transmitter's current limiting (23 mA typical) protects the loop from overcurrent conditions.
Periodically verify the 4-20 mA output against a known vibration source to confirm accuracy. Following the manufacturer's maintenance guidelines will extend service life and minimize unplanned downtime.
Compatibility and Integration
The 990-10-70-03-CN is designed to work with Bently Nevada 3300 NSv proximity probes and extension cables. It outputs a standard 4-20 mA signal, making it compatible with most industrial control systems. The maximum loop resistance of 1,000 Ω at 35 Vdc ensures stable operation over long cable runs.
For hazardous area installations, the transmitter is available with country-specific approvals (CN option). Always verify that the selected model meets the area classification requirements.
Product Support and Availability
The 990-10-70-03-CN is available from AutoDCSTech. For ordering assistance or technical questions, contact our team. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
