Bently Nevada 990-04-70-02-05 Vibration Transmitter 4-20 mA

Bently Nevada 990-04-70-02-05 Vibration Transmitter

Product Introduction

The Bently Nevada 990-04-70-02-05 belongs to the trusted 990 series of vibration transmitters. This device converts shaft vibration into a standard 4-20 mA signal for integration with PLCs, DCS, or SCADA systems. Specifically, it supports a full-scale range of 0-4 mils (0-100 μm) peak-to-peak. Furthermore, the system length of 7.0 meters provides flexibility for remote mounting. This model also includes bulkhead screw mounting and comprehensive agency approvals for global use.

Key Technical Specifications

The 990-04-70-02-05 offers robust performance for predictive maintenance. Its primary function is to accept input from one non-contacting 3300 NSv proximity probe and extension cable. The transmitter then conditions this signal into a 2-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.

• Loop Accuracy: Within ±1.5% over the full-scale range (test signal to 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 for reliability in harsh conditions. Its mechanical design includes bulkhead screw mounting for secure installation. The unit weighs only 0.43 kg (0.9 lbm), making it lightweight and easy to handle.

• Operating Temperature: Standard industrial range (refer to manual for exact limits).

• Enclosure: Robust housing suitable for hazardous area locations.

• Mounting Option: 02 Bulkhead screws for panel or machine mounting.

• Agency Approval Option: 05 – CSA Division 2, ATEX Zone 0, ATEX Zone 2, and includes ABS maritime approval.

Installation and Wiring Guidelines

Proper installation ensures accurate measurement and long service life. First, mount the Bently Nevada 990-04-70-02-05 using the bulkhead screws provided. Next, connect the 3300 NSv probe and extension cable to the transmitter input. Remember to gap the probe between 0.5 and 1.75 mm from the target surface to achieve the full-scale range.

For the output, wire the transmitter in a 2-wire loop configuration. The power supply should provide between +12 and +35 Vdc. Additionally, the total loop resistance must not exceed 1,000 Ω at 35 Vdc to maintain proper operation. The transmitter includes non-interacting external zero and span adjustments for convenient calibration.

Not OK and Signal Defeat Features

The 990-04-70-02-05 incorporates a built-in “Not OK” detection circuit. If a fault condition occurs, the signal output drops to less than 3.6 mA within 100 µs. This fast response allows control systems to recognize a failure immediately. Once the fault is resolved, the output restores automatically within 2-3 seconds. This feature enhances system safety and diagnostic capability.

Packaging List

• 1 x Bently Nevada 990-04-70-02-05 Vibration Transmitter

• Mounting hardware (bulkhead screws)

• Product documentation and installation guide (if available)

Note: The 3300 NSv probe, extension cable, and power supply are sold separately.

Shipping Information

All orders are shipped via FedEx, UPS, or DHL to ensure fast and reliable delivery. Please contact us for current lead times and shipping costs.

Frequently Asked Questions (FAQ)

1. What is the full-scale range of the 990-04-70-02-05?
The full-scale option 04 provides a range of 0-4 mils peak-to-peak, which is equivalent to 0-100 μm. This range is suitable for monitoring small shaft vibrations in high-speed machinery.

2. Can I use this transmitter with a different probe?
The Bently Nevada 990-04-70-02-05 is specifically designed to accept only one 3300 NSv proximity probe and its matching extension cable. Using other probes may result in inaccurate readings or damage to the unit.

3. What power supply do I need for the 990-04-70-02-05?
You need a DC power supply between +12 and +35 Vdc connected at the transmitter terminals. For a 28 V supply, the maximum loop resistance is approximately 1,000 Ω.

4. Is the 990-04-70-02-05 approved for use in hazardous areas?
Yes. The agency approval option 05 includes CSA Division 2, ATEX Zone 0, ATEX Zone 2, and ABS maritime approval. This makes it suitable for a wide range of explosive and offshore environments.

5. How do I adjust the zero and span on this transmitter?
The 990-04-70-02-05 features non-interacting external adjustments for zero and span. You can fine-tune these settings during installation using a small screwdriver while monitoring the 4-20 mA output. Always refer to the product manual for detailed calibration steps.