Bently Nevada 990-08-70-03-00 Vibration Transmitter

Bently Nevada 990-08-70-03-00 Vibration Transmitter

Product Introduction

The Bently Nevada 990-08-70-03-00 vibration transmitter delivers reliable shaft vibration monitoring. This device works with a non-contacting 3300 NSv proximity probe and extension cable. It converts probe signals into a standard 4-20 mA output. Many industrial plants use this 990-08-70-03-00 for rotating machinery protection. Additionally, its compact design simplifies installation in control cabinets.

Key Technical Specifications

Input and Power Requirements

This transmitter accepts one non-contacting 3300 NSv proximity probe. It also supports the associated extension cable. Power requirements are straightforward. The Bently Nevada 990-08-70-03-00 needs +12 to +35 Vdc at the transmitter terminal. You must supply this voltage from an external source.

Output and Loop Characteristics

The device provides a 4 to 20 mAdc signal over its specified full-scale range. It uses a standard 2-wire configuration. Maximum loop resistance reaches 1,000 Ω including cable at 35 Vdc. Typical current limiting is 23 mA. Loop accuracy measures within ±1.5% over the full-scale range. Note that this error adds to the Prox Out Incremental Scale Factor.

Probe Gap and Setup

Proper probe gap is critical for correct operation. The probe must sit between 0.5 and 1.75 mm (20 and 55 mils) from the target. This gap ensures the full-scale range works correctly. Additionally, the minimum target size is 9.5 mm (0.375 in) diameter.

Frequency Response and Not OK Function

Frequency response spans from 5 Hz to 6,000 Hz +0, 3 dB. This range covers most vibration monitoring needs. Furthermore, the signal output drops to less than 3.6 mA within 100 µs after a Not OK condition. The output restores within 2-3 seconds after the Not OK condition clears.

Full-Scale and System Options

This specific model includes several factory-set options. The full-scale option is 08 for 0-8 mils pp (0-200 μm pp). System length option is 70, which means a 7.0 meter (23.0 feet) total length. Mounting option 03 provides DIN clips and screws. Agency approval option 00 means not required.

Mechanical and Environmental Data

Transmitter weight is 0.43 kg (0.9 lbm). Leadwire length for the Proximitor Sensor Output (BNC connector) has a maximum of 3 meters (10 feet). This transmitter suits non-hazardous, Zone 2 or Div 2 hazardous area locations. A 28 V power supply is commonly used with this device.

Installation Guidelines

Mounting the Transmitter

Use the provided DIN clips and screws for installation. First, attach the clips securely to a DIN rail. Next, place the 990-08-70-03-00 onto the clips. Then tighten the screws to lock it in place. Ensure the transmitter stays away from high heat sources.

Connecting the Probe and Cable

Connect one non-contacting 3300 NSv proximity probe to the input. You can add an extension cable if needed. Keep the total cable length within the specified limit. For the BNC connector output, the maximum cable distance is 3 meters.

Wiring the 4-20 mA Loop

Wire the transmitter in a 2-wire configuration. Connect the positive lead to a +12 to +35 Vdc supply. Then connect the negative lead to the loop load. Maximum loop resistance is 1,000 Ω at 35 Vdc. For example, a typical 250 Ω resistor works well for many PLC inputs.

Adjusting Zero and Span

The Bently Nevada 990-08-70-03-00 provides non-interacting external adjustments. You can set zero and span independently. Use a small screwdriver to make these adjustments. Verify the output with a known vibration source.

Testing the Installation

Apply power and check the output current. With the probe properly gapped, the output should read 4 mA at zero vibration. Then introduce a known vibration signal. The output should increase linearly to 20 mA at full scale. Use the TEST signal input to verify loop accuracy.

Packaging List

• Bently Nevada 990-08-70-03-00 vibration transmitter (1 unit)

• DIN clips and screws for mounting (option 03)

• Product documentation sheet

• Terminal block connectors

Note: The probe and extension cable are sold separately.

Shipping Information

All orders ship via FedEx, UPS, or DHL. Delivery times depend on your location. Express shipping options are available.

Frequently Asked Questions (FAQ)

1. What probe works with the Bently Nevada 990-08-70-03-00?
This transmitter accepts one non-contacting 3300 NSv proximity probe and its extension cable. No other probe types are compatible.

2. What happens if the probe gap is incorrect?
The output signal may not cover the full 4-20 mA range. Additionally, measurement accuracy will suffer. Always set the gap between 0.5 and 1.75 mm.

3. Can I use this transmitter in a hazardous location?
Yes, it suits Zone 2 or Div 2 hazardous area locations. A 28 V power supply is commonly used in such areas. However, always follow local safety codes.

4. How do I know if a Not OK condition occurs?
The signal output drops to less than 3.6 mA within 100 µs. This fast response alerts your control system immediately. The output recovers within 2-3 seconds after the fault clears.

5. What is the maximum cable length from the Proximitor output?
The maximum cable distance for the Proximitor Sensor Output (BNC connector) is 3 meters (10 feet). Longer cables may cause signal degradation.