
Product Overview
The Bently Nevada 990-04-50-02-00 is a compact vibration transmitter designed primarily for OEMs of centrifugal compressors, pumps, motors, and fans. It provides a 4–20 mA output proportional to shaft vibration, enabling integration into standard control systems without requiring external monitoring equipment.
Applications
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Centrifugal air compressors
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Small motors and pumps
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Fans and blowers
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Machinery with limited mounting space
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OEM equipment requiring simplified vibration inputs
Advantages
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Integrated Proximitor Sensor eliminates external processing units
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Dual mounting options: DIN rail or bulkhead
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Rugged, potted construction for high-humidity environments
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Quick signal testing with built-in test input
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“Not OK” circuit prevents false alarms from sensor faults
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Compatible with 3300 NSv proximity probes
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Dynamic signal output available for diagnostics
Technical Specifications
| Parameter | Description |
|---|---|
| Input | 3300 NSv proximity probe with 5m cable |
| Output | 4–20 mA current loop (2-wire) |
| Frequency Range | 5 Hz to 6,000 Hz |
| Accuracy | ±1.5% full scale |
| Power Supply | +12 to +35 Vdc |
| Max Loop Resistance | 1000 Ω at 35 Vdc |
| Probe Gap Range | 0.5 mm to 1.75 mm |
| Prox Out Scale Factor | 7.87 mV/μm ±6.5% typical |
| Operating Temp (Transmitter) | -35°C to +85°C |
| Storage Temp (Transmitter) | -52°C to +100°C |
| Humidity | 100% condensing |
| Dimensions (L x W x H) | 100.1 x 73.9 x 53.3 mm |
| Weight | 0.43 kg |
| Certifications | ATEX, CSA Div 2, ABS, RoHS, FCC, EMC |
FAQs
Q1: What type of sensor is compatible with the 990 transmitter?
A: The 990 transmitter is designed to work with the Bently Nevada 3300 NSv proximity probe system.
Q2: Can the transmitter be mounted on a DIN rail?
A: Yes, it supports DIN rail or bulkhead mounting.
Q3: Does it provide diagnostic signal output?
A: Yes, a non-isolated PROX OUT BNC is provided for diagnostics.
Q4: Is the output isolated?
A: The PROX OUT signal is not isolated; use the 122115-01 Test Adapter for safe diagnostics.
Q5: What is the primary use case?
A: OEMs use it for simple vibration monitoring in compressors, pumps, and motors.
Q6: What environmental conditions can it handle?
A: It supports up to 100% condensing humidity and operates from -35°C to +85°C.
Q7: What happens during a probe fault?
A: The signal drops below 3.6 mA to indicate a “Not OK” condition.
Q8: Can it be used for phase analysis?
A: No, it provides only vibration amplitude—not phase information.
Q9: How do you test the 4–20 mA loop?
A: A test input pin is available for signal verification using a function generator.
Q10: What kind of approval does it have for hazardous areas?
A: It holds ATEX Zone 0/2 and CSA Div 2 hazardous location approvals.
Related Models (Same Series)
| Model | Output Range | Cable Length | Mounting | Approval |
|---|---|---|---|---|
| 990-04-70-02-00 | 0–4 mils | 7.0 m | Bulkhead | ATEX, CSA Div 2 |
| 990-05-50-02-00 | 0–5 mils | 5.0 m | Bulkhead | ATEX, CSA Div 2 |
| 990-08-50-02-00 | 0–8 mils | 5.0 m | Bulkhead | ATEX, CSA Div 2 |
| 990-10-70-02-00 | 0–10 mils | 7.0 m | Bulkhead | ATEX, CSA Div 2 |
| 990-04-50-01-00 | 0–4 mils | 5.0 m | DIN rail | No Approval |
| 990-05-70-03-05 | 0–5 mils | 7.0 m | Both | All Approvals |
Popular Bently Nevada Models
| Model | Description | Key Feature | Dimensions (mm) | Weight |
|---|---|---|---|---|
| 3500/42M | Proximitor Seismic Monitor | High-speed dynamic signal capture | 241 x 24 x 254 | 0.68 kg |
| 3500/22M | Transient Data Interface | System 1 integration | 241 x 24 x 254 | 0.62 kg |
| 3500/20 | Rack Interface Module | I/O connectivity | 241 x 24 x 254 | 0.55 kg |
| 3500/15 | Power Supply Module | Redundant supply support | 241 x 24 x 254 | 0.82 kg |
| 3500/94 | Display Interface | Full LCD front panel | 241 x 48 x 254 | 1.1 kg |
| 330180-91-CN | 3300 XL Proximitor Sensor | Standard 8 mm eddy-current probe | 100.1 x 73.9 x 53.3 | 0.43 kg |
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