Bently Nevada 990-04-50-02-00 2-Wire Vibration Transmitter

Description

The 990-04-50-02-00 is a compact loop-powered vibration transmitter used to convert proximity probe displacement into a standard 4 to 20 mA signal for industrial monitoring systems. It is designed for applications where vibration data is required for continuous trend observation and basic protection logic rather than full waveform diagnostics.

This version uses a bulkhead screw mounting arrangement, which is often preferred in control panel designs where direct enclosure mounting is required. In practice, engineers choose this type when they want a rigid installation point that reduces mechanical movement and simplifies wiring routing inside tight cabinets.

The device operates with a 3300 NSv proximity probe system and supports a 5.0 meter system length. This configuration is commonly applied in compressor packages, pump systems, and fan assemblies where probe installation distance is moderate and routing is straightforward.

The design focus is operational simplicity: once installed and commissioned, it typically runs continuously with minimal adjustment.

Engineering Characteristics

• 2-wire loop-powered vibration transmitter architecture
• Converts proximity probe signal into 4–20 mA output
• Designed for 3300 NSv probe compatibility
• Bulkhead screw mounting with 4-point fixation
• Supplied with 6-32 x 1.326 mounting screws when specified
• Integrated signal conditioning electronics
• Stable output for continuous vibration trending
• External zero/span adjustment capability
• PROX OUT available for diagnostic signal access
• Fault indication via output current drop behavior

Application Perspective

Ordering Structure

Mechanical & Installation Data

Interface Overview

Installation Notes (Field Engineering View)

Bulkhead mounting is typically selected when the panel layout requires a fixed and mechanically stable installation point. The four-point fixation reduces vibration-induced loosening, which can be a concern in compressor or pump skid environments.

In practical wiring design, probe signal routing should be separated from high-voltage or high-current conductors. This helps avoid induced noise, especially when cable runs are bundled inside compact enclosures.

Before commissioning, verify probe gap alignment and confirm loop current stability under steady machine operation. Engineers usually delay alarm logic activation until the signal behavior is confirmed under real operating conditions.

PROX OUT is mainly used during maintenance or diagnostic checks rather than continuous monitoring in production.

FAQ

Why is bulkhead mounting used in this model?
It provides a rigid enclosure-mounted installation with better mechanical stability.

Are mounting screws included?
Yes, 6-32 x 1.326 screws are provided when the mounting option is specified.

What is the main function of this transmitter?
It converts vibration from a proximity probe into a 4–20 mA signal.

Can it be used with PLC systems?
Yes, it is designed for direct PLC and DCS analog input integration.

What probe system is required?
It is designed for Bently Nevada 3300 NSv proximity probes.

Is this suitable for compressor applications?
Yes, it is commonly used on compressors, pumps, and fans.

Does it support vibration diagnostics?
It provides PROX OUT for basic diagnostic signal access.

Is it a full monitoring system?
No, it is a simplified vibration transmitter for trend-level monitoring.

What happens if the probe fails?
The output current drops to indicate a fault condition.

Where is it typically installed?
Inside control cabinets or skid-mounted equipment panels.