990-04-50-01-01 Vibration Transmitter Overview
When rotating machinery health is critical, the 990-04-50-01-01 from Bently Nevada provides a dependable solution. This 990 Vibration Transmitter accepts one non-contacting 3300 NSv Proximity Probe and extension cable, converting vibration into a standard 4-20 mA signal. Designed for industrial environments, it offers a full-scale range of 0-4 mils pp (0-100 μm pp) and mounts on 35 mm DIN rail clips. With CSA Division 2 approval, it suits hazardous area installations.
Key Features and Technical Specifications
- 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).
- Probe gap: Must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from target.
- 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).
One distinctive spec is the frequency response from 5 Hz to 6,000 Hz. This wide range captures both low-speed and high-speed machine vibrations, making the transmitter versatile across different rotating equipment.
Installation and Setup
Mount the 990-04-50-01-01 on a standard 35 mm DIN rail using the included clips. Ensure the proximity probe is gapped correctly between 0.5 and 1.75 mm (20 and 55 mils) from the target to achieve full-scale range. Wire the transmitter in a 2-wire loop, connecting the power supply (+12 to +35 Vdc) and the 4-20 mA output. Keep the leadwire length from the Proximitor Sensor Output (BNC connector) to a maximum of 3 meters (10 feet). Use the non-interacting external zero and span adjustments to calibrate the output.
Maintenance and Reliability
Regularly inspect the transmitter and probe connections for signs of wear or loose terminations. Verify the probe gap periodically, as changes can affect measurement accuracy. The 990-04-50-01-01 is designed for reliable operation, but routine checks help prevent unexpected failures. Since it is rated for CSA Division 2 hazardous areas, follow all local safety regulations during maintenance.
Applications and Use Cases
This vibration transmitter is ideal for monitoring pumps, fans, compressors, and other rotating machinery in industrial plants. Its 4-20 mA output integrates easily with PLCs, DCS, and SCADA systems. The compact DIN rail mounting simplifies installation in control panels. For maintenance engineers, the transmitter's ability to provide continuous vibration data helps detect early signs of bearing wear or imbalance, reducing unplanned downtime.
Compatibility and Integration
The 990-04-50-01-01 works with Bently Nevada 3300 NSv proximity probes and extension cables. Its 4-20 mA output is universally accepted by most monitoring systems. The transmitter is powered by a +12 to +35 Vdc supply, making it compatible with typical industrial power sources. For hazardous area installations, the CSA Division 2 approval ensures safe operation in Zone 2 or Div 2 locations.
Troubleshooting Common Issues
If the output signal is not within the expected range, first check the probe gap and ensure it is within 0.5 to 1.75 mm. Verify the power supply voltage is between +12 and +35 Vdc. If the signal goes below 3.6 mA, it indicates a Not OK condition; the output will restore within 2-3 seconds after the condition is removed. For persistent issues, consult the official Bently Nevada manual or contact AutoDCSTech for support.
Product Support and Availability
The 990-04-50-01-01 is available from AutoDCSTech. Please verify current lifecycle status and availability with AutoDCSTech before ordering. For technical assistance, contact our team.
