Case Study: Solving Vibration Monitoring Challenges with the 990-05-70-03-01
In a rotating machinery environment, unmonitored vibration can lead to catastrophic failure. An engineer responsible for a critical compressor train needed a reliable way to transmit vibration data to a PLC. The 990-05-70-03-01 from Bently Nevada provided the solution. This 990 Vibration Transmitter accepts a single non-contacting 3300 NSv Proximity Probe and converts the signal into a standard 4-20 mA loop. With a full-scale range of 0-5 mils pp (0-125 μm pp), it delivered the precise data needed to protect the asset.
Key Features of the 990-05-70-03-01
- Accepts one non-contacting 3300 NSv Proximity Probe and extension cable.
- Requires +12 to +35 Vdc input at the transmitter terminal.
- Provides a 4-20 mAdc signal output over the specified full-scale range in a 2-wire configuration.
- Offers 4-20 mA loop accuracy within ±1.5% over the specified full-scale range.
- Features non-interacting external zero and span adjustments.
- Includes NOT OK/signal defeat: output goes to less than 3.6 mA within 100 µs after a Not OK condition.
- Frequency response of 5 Hz to 6,000 Hz +0, 3 dB.
The 990-05-70-03-01 is designed for reliable operation in hazardous areas, with CSA Division 2 approval. Its maximum loop resistance is 1,000 Ω including cable at 35 Vdc, ensuring compatibility with most control systems.
Applications and Use Cases
This vibration transmitter is ideal for monitoring pumps, motors, fans, and other rotating equipment. In a typical installation, the probe is gapped between 0.5 and 1.75 mm (20 and 55 mils) from the target to ensure full-scale range. The 4-20 mA output can be directly interfaced with PLCs, DCS, or standalone monitors. Consequently, it simplifies integration and reduces the need for additional signal conditioning.
Installation and Setup
Mounting is straightforward with the included DIN clips and screws (Mounting Option 03). The system length option of 7.0 meters (23.0 feet) provides flexibility for probe placement. During installation, ensure the probe gap is set correctly, and the leadwire length from the Proximitor Sensor Output (BNC connector) does not exceed 3 meters (10 feet). Power supply of 28 V is recommended for optimal performance.
Maintenance and Reliability
Regular inspection of the probe and cable is recommended to ensure accurate readings. The transmitter's current limiting is 23 mA typical, protecting the loop from overcurrent. Because the device is rated for CSA Division 2 hazardous locations, it is built to withstand demanding industrial environments. Therefore, it offers long-term reliability and reduced maintenance costs.
Compatibility and Integration
The 990-05-70-03-01 is compatible with Bently Nevada 3300 NSv Proximitor systems. Its 2-wire 4-20 mA output simplifies connection to standard analog input modules. The non-interacting zero and span adjustments allow for easy calibration without affecting the other parameter. This makes it a versatile choice for retrofitting existing monitoring systems.
Troubleshooting Common Issues
If the output signal is not within the expected range, check the probe gap and ensure it is within 0.5 to 1.75 mm. Verify the supply voltage is between +12 and +35 Vdc. If a Not OK condition occurs, the output will drop below 3.6 mA within 100 µs, and it will restore within 2-3 seconds after the condition is removed. Always verify the loop resistance does not exceed 1,000 Ω at 35 Vdc.
Product Support and Availability
The 990-05-70-03-01 is available from AutoDCSTech. As a leading supplier of industrial automation parts, AutoDCSTech ensures genuine Bently Nevada products. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
