990-04-50-02-05 990 Vibration Transmitter Bently Nevada Module

Product Overview

The 990-04-50-02-05 is a compact, loop-powered vibration monitoring solution developed by Bently Nevada within the trusted 990 Series. Designed as an integrated Vibration Transmitter, this unit directly accepts inputs from a 3300 NSv proximity probe and extension cable, converting mechanical displacement into a standard 4 to 20 mA proportional output for direct connection to PLC or DCS control architectures.

Configuration Breakdown & Suffix Codes

• Base Model: 990 Vibration Transmitter System
• Full-Scale Option (04): 0 to 4 mils pp (0 to 100 micrometers pp) measurement range
• System Length Option (50): 5.0 meters (16.4 feet) total system length
• Mounting Option (02): Bulkhead mounting screws configuration
• Agency Approval Option (05): CSA Division 2, ATEX Zone 0, ATEX Zone 2, and ABS maritime approvals

Technical Specifications

• Brand: Bently Nevada
• Manufacturer Part Number: 990-04-50-02-05
• Input Compatibility: One non-contacting 3300 NSv Proximity Probe and extension cable
• Power Supply: +12 to +35 Vdc input at transmitter terminals
• Signal Output: 4 to 20 mAdc over specified full-scale range in 2-wire configuration
• Loop Accuracy: Within plus-minus 1.5 percent over specified full-scale range
• Maximum Loop Resistance: 1,000 Ohms including cable at 35 Vdc
• Current Limiting: 23 mA typical protection threshold
• Frequency Response: 5 Hz to 6,000 Hz (+0, -3 dB)
• Probe Gap Requirement: 0.5 to 1.75 mm (20 to 55 mils) from target
• Minimum Target Size: 9.5 mm (0.375 in) diameter
• Unit Weight: 0.43 kg (0.9 lbm)

Packaging List & Commercial Terms

• One 990-04-50-02-05 vibration transmitter unit
• Bulkhead mounting hardware pack
• Manufacturer compliance documentation and calibration sheet
• Warranty: Comprehensive 12-month factory coverage
• Fulfillment: Rapid global shipping via FedEx, UPS, and DHL within 24-48 hours

Target Machinery & Application Scenarios

• Small to medium-sized industrial centrifugal pumps and blowers.
• Compact electric motors and overhung process compressors.
• Marine auxiliary rotating equipment requiring ABS maritime certification.
• Skid-mounted balance-of-plant machinery where rack-based monitors are unnecessary.

Diagnostic Capability

• Provides continuous 4-20mA trend data for real-time shaft relative vibration tracking.
• Features automated NOT OK signal defeat, dropping output below 3.6 mA within 100 microseconds upon transducer faults.
• Supports local diagnostic signal checking via BNC connector with up to 3 meters of leadwire accommodation.

Global PLC Spare HUB's Insight

When commissioning the 990-04-50-02-05 in harsh industrial environments, instrument technicians should verify that total loop resistance—including barrier impedances—does not exceed 1,000 Ohms at 35 Vdc. Proper shielding grounded strictly at the control system cabinet prevents electromagnetic induction from corrupting the low-level 4-20mA process loop.

Model Selection and Comparison Analysis

When engineering machinery protection loops, selecting the correct transmitter variant depends heavily on the mechanical measurement axis and physical scale requirements. For instance, comparing the current radial vibration unit with the alternative model 991-06-50-02-01 Bently Nevada Thrust Vibration Transmitter Module Unit highlights a fundamental application shift: while the 990-04-50-02-01 series is engineered primarily for radial shaft vibration monitoring (0 to 4 mils range), the 991 series is specifically optimized for axial thrust position (monitor axial displacement) with distinct scale factors and hazardous ratings (such as CSA/ATEX Zone 2 with option 01). Choose the 990 transmitter for casing-mounted radial displacement tracking, and reserve 991 units strictly for rotor end-play and thrust bearing wear monitoring.

Frequently Asked Questions

Question: What action does the transmitter take during a transducer failure?

Answer: Under a Not OK condition, the signal output drops below 3.6 mA within 100 microseconds to alert the control system of a loop fault.

Question: Can I adjust the zero and span settings in the field?

Answer: Yes, the unit features non-interacting external adjustments allowing precise calibration during routine maintenance checks.

Question: What is the maximum allowable cable distance for the BNC test port?

Answer: The maximum leadwire length for the Proximitor Sensor BNC output connector is restricted to 3 meters (10 feet).

Question: Are zero and span adjustments mutually dependent?

Answer: No, the transmitter utilizes non-interacting external adjustments, meaning modifying the zero setting does not alter the calibrated span.

Question: How should loop power supplies be configured in Class I Division 2 areas?

Answer: Ensure the DC power supply output does not exceed 28 volts when operating within non-hazardous or Zone 2/Div 2 classified per installation drawings.

Buying Guide

• Verify that your control system input card accepts standard 2-wire 4 to 20 mA loop signals.
• Confirm that the 5.0-meter system length matches the physical separation distance between your probe installation point and transmitter mounting location.
• Select expedited courier options like DHL or FedEx to ensure rapid delivery for urgent plant turnarounds.

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