Bently Nevada 990-08-70-02-01 Vibration Transmitter

Bently Nevada 990-08-70-02-01 Vibration Transmitter

Product Introduction

The Bently Nevada 990-08-70-02-01 is a member of the field-proven 990 series of vibration transmitters. This device translates shaft displacement into a standardized 4-20 mA current loop signal, which integrates seamlessly with most control systems. Specifically, this variant features a full-scale range of 0-8 mils (0-200 μm) peak-to-peak, making it ideal for machines with moderate vibration amplitudes. Furthermore, it includes a 7.0-meter system length and bulkhead screw mounting for straightforward installation. This model carries a CSA Division 2 approval for use in ordinary or hazardous locations.

Key Technical Specifications

The 990-08-70-02-01 provides accurate, repeatable measurements for predictive maintenance strategies. Its core function is to accept input from one non-contacting 3300 NSv proximity probe and its matching extension cable. The transmitter then conditions this raw signal into a two-wire, 4-20 mA loop-powered output.

• Input: Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.

• Power Supply: Requires +12 to +35 Vdc input at the transmitter terminal.

• Output Signal: 4 to 20 mAdc over the specified full-scale range (0-8 mils).

• Loop Accuracy: Within ±1.5% over the full-scale range, measured from TEST signal to a 250 Ω load. This error is additional to the Prox Out Incremental Scale Factor.

• 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.

• Probe Gap: Must be set between 0.5 and 1.75 mm (20 and 55 mils) from the target.

• Minimum Target Size: 9.5 mm (0.375 in) diameter.

• Leadwire Length: Maximum 3 meters (10 feet) for Proximitor Sensor Output (BNC connector).

Environmental and Mechanical Data

This transmitter is built to withstand demanding industrial conditions. Its compact housing and bulkhead screw mounting option ensure a secure fit on panels or machine frames.

• Transmitter Weight: 0.43 kg (0.9 lbm).

• Mounting Option: 02 Bulkhead screws for permanent installation.

• Agency Approval Option: 01 CSA Division 2 for use in hazardous locations.

• System Length Option: 70 7.0 meters (23.0 feet) total cable length.

Installation and Wiring Guidance

Correct installation is essential for optimal performance. Begin by mounting the Bently Nevada 990-08-70-02-01 using the bulkhead screws provided. Then, connect the 3300 NSv probe and extension cable to the transmitter's input port. Ensure the probe tip is gapped between 0.5 and 1.75 mm from the target surface; this gap is critical to achieve the full 0-8 mil range.

For the output wiring, set up a two-wire loop with a DC power supply between +12 and +35 Vdc. The total loop resistance, including the cable, must not exceed 1,000 Ω at 35 Vdc. The 990-08-70-02-01 offers non-interacting external zero and span potentiometers, allowing you to calibrate the output without affecting the other parameter.

Not OK and Signal Defeat Functionality

This transmitter includes a built-in self-diagnostic feature. When a fault or "Not OK" condition occurs—such as a broken probe cable or loss of power—the output current drops below 3.6 mA within 100 µs. Consequently, your control system can detect this failure almost instantly. Once the issue is corrected, the signal automatically returns to normal within 2-3 seconds. This rapid response enhances system reliability and simplifies troubleshooting.

Packaging List

• 1 x Bently Nevada 990-08-70-02-01 Vibration Transmitter

• Bulkhead screw mounting hardware

• Installation and wiring instruction sheet

Please note: The 3300 NSv proximity probe, extension cable, and external power supply are not included and must be ordered separately.

Shipping Information

We ship all orders via FedEx, UPS, or DHL to ensure timely and secure delivery. Contact our sales team for current stock availability and shipping estimates.

Frequently Asked Questions (FAQ)

1. What vibration range does the 990-08-70-02-01 measure?
This model measures peak-to-peak vibration from 0 to 8 mils (0 to 200 μm). The 08 full-scale option defines this specific range, which suits medium-vibration machinery like pumps, fans, and compressors.

2. Is the 990-08-70-02-01 compatible with other Bently Nevada probes?
No. The Bently Nevada 990-08-70-02-01 is designed exclusively for use with the 3300 NSv proximity probe and its designated extension cable. Using other probe types will cause inaccurate readings and may damage the transmitter.

3. What power supply should I use for this transmitter?
You need a regulated DC power supply providing between +12 and +35 Vdc at the transmitter terminals. For a 28 V supply, the maximum allowable loop resistance is 1,000 Ω including all cables and loads.

4. Where can I install the 990-08-70-02-01?
This unit carries a CSA Division 2 approval (Option 01). Therefore, it is suitable for installation in ordinary locations or Class I, Division 2 hazardous areas. Always verify local regulations and site-specific requirements before installation.

5. How do I adjust the zero and span on the 990-08-70-02-01?
The transmitter features non-interacting external zero and span adjustments. You can calibrate the 4 mA and 20 mA setpoints using a small screwdriver while monitoring the loop current. Consult the product manual for the complete calibration procedure.