Bently Nevada 990-08-50-03-00 Vibration Transmitter

Bently Nevada 990-08-50-03-00 Vibration Transmitter

Product Introduction

The Bently Nevada 990-08-50-03-00 functions as a loop-powered, 2-wire vibration transmitter for continuous machinery protection. This device accepts input from one non-contacting 3300 NSv proximity probe and its corresponding extension cable. It then translates the dynamic vibration signal into a proportional 4-20 mA analog output. This loop-powered design streamlines installation because it removes the need for separate power and signal conductors. Consequently, users benefit from reduced wiring complexity and lower overall system costs. This particular version features a full-scale range of 0-8 mils pp (0-200 μm pp) combined with a 5.0-meter system length. Therefore, it suits applications requiring measurement of larger vibration amplitudes, such as certain compressors and larger rotating equipment.

Technical Specifications

Measurement and Output Performance

This transmitter produces a 4 to 20 mAdc signal across its specified full-scale range using a standard 2-wire configuration. The loop accuracy achieves within ±1.5% over the full-scale range, rated from the TEST signal input to the voltage measured across a 250 Ω loop resistance. Notably, this ±1.5% error exists in addition to the Prox Out Incremental Scale Factor. The frequency response covers 5 Hz to 6,000 Hz (+0, 3 dB) . Thus, it captures vibration events across a wide range of rotational speeds, from slow-speed machinery to high-speed turbines.

Power Requirements and Electrical Characteristics

The device demands a +12 to +35 Vdc input at the transmitter terminal for correct operation. The maximum loop resistance reaches 1,000 Ω , including all cable resistance, at 35 Vdc. Typical current limiting occurs at 23 mA to safeguard the circuit against overcurrent situations. Furthermore, this transmitter includes a NOT OK/signal defeat feature. When a Not OK condition appears, the signal output falls to less than 3.6 mA within 100 µs. The output then returns to normal operation within 2-3 seconds after the condition resolves. Zero and span adjustments use non-interacting external potentiometers, making field calibration quick and straightforward.

Probe Compatibility and System Integration

The Bently Nevada 990-08-50-03-00 integrates seamlessly with 3300 NSv proximity probes and their matching extension cables. The minimum target size for reliable detection measures 9.5 mm (0.375 in) in diameter. For the Proximitor Sensor Output with BNC connector, the maximum leadwire length extends to 3 meters (10 feet). The transmitter weighs a lightweight 0.43 kg (0.9 lbm) , facilitating easy handling during installation. This model includes Option 03, which provides DIN clips and screws for secure mounting to a DIN rail. Additionally, the probe requires a gap between 0.5 and 1.75 mm (20 and 55 mils) from the target to maintain accurate full-scale range operation.

Mechanical and Environmental Specifications

The 990-08-50-03-00 offers dependable performance across diverse industrial settings. Its Agency Approval Option is 00, meaning this configuration does not require formal agency certifications. Nevertheless, the device remains appropriate for Non-Hazardous, Zone 2, or Div 2 hazardous area locations when powered with a 28 V supply. The DIN rail mounting with clips and screws provides extra stability in high-vibration environments. In addition, its compact form factor conserves valuable panel space while its robust construction endures typical industrial operating conditions.

Installation and Configuration Guidelines

Correct installation ensures measurement accuracy and long-term reliability. First, mount the transmitter onto a standard 35 mm DIN rail using the provided clips and screws. Tighten the screws securely to prevent movement from vibration. Next, connect the device to your 3300 NSv proximity probe system with care. Ensure that the total probe length combined with the extension cable length equals the 5.0-meter (16.4 feet) system length option. For field wiring, connect the transmitter in a 2-wire, loop-powered configuration, observing correct polarity (+ and -). We strongly recommend using a three-conductor shielded triad cable for superior noise immunity and signal integrity. After that, adjust the probe to the recommended gap setting of 1.0 mm (40 mils) . Meanwhile, verify that this gap stays within the 0.5 to 1.75 mm linear range for optimal performance. Finally, perform zero and span adjustments using the external potentiometers. Apply a known reference signal to the TEST input and adjust until the output matches your desired values.

Packaging List

• 1 x Bently Nevada 990-08-50-03-00 Vibration Transmitter

• 1 x DIN rail mounting kit (clips and screws)

• 1 x 3/4-14 NPT plug

Shipping Information

All orders ship via FedEx, UPS, or DHL to ensure fast and secure worldwide delivery. Each transmitter receives careful packaging to prevent damage during transit.

Frequently Asked Questions (FAQ)

1. What measurement range does this transmitter offer?
The 990-08-50-03-00 model provides a full-scale range of 0-8 mils pp (0-200 μm pp) . The suffix '08' in the product number identifies this specific range.

2. Which probes are compatible with this transmitter?
This device accepts one non-contacting 3300 NSv Proximity Probe along with its matching extension cable. No other probe types will work correctly with this unit.

3. How does the mounting differ from other 990 transmitters?
This version uses Option 03, which includes DIN clips and screws for secure mounting. The screws provide additional holding force compared to clips alone, making it suitable for high-vibration areas.

4. What does the output signal do during a fault condition?
During a Not OK condition, such as a broken probe circuit, the signal output drops to less than 3.6 mA within 100 µs. This rapid response provides immediate fault indication to your monitoring system.

5. What are typical applications for this transmitter?
The Bently Nevada 990-08-50-03-00 works well for continuous vibration monitoring of rotating equipment. Common applications include centrifugal pumps, motors, compressors, and industrial fans that produce moderate to high vibration amplitudes.