The Bently Nevada 990-05-50-02-00 990 Vibration Transmitter is primarily designed for Original Equipment Manufacturers (OEMs) of centrifugal air compressors, small pumps, motors, or fans. It provides a simple 4 to 20 mA proportional vibration signal for machinery control systems. The transmitter is a 2-wire, loop-powered device compatible with the 3300 NSv proximity probe.

Key Features

• Integrated Proximitor Sensor, eliminating the need for an external unit.
• “PROX OUT” and “COM” terminals for dynamic vibration and gap voltage signal output for diagnostics.
• Non-interacting zero and span potentiometers for loop adjustment.
• Test Input pin for quick signal verification.
• Not OK/Signal Defeat circuit to prevent false alarms.
• Mounting options: DIN-rail clips or bulkhead mounting screws.
• Potted construction for high humidity environments.
• Compatible with 3300 NSv proximity probe for installation in tight spaces.

Notes:

1. Vibration transmitters have limitations compared to continuous vibration monitoring systems. They are suitable for general vibration level measurement and trending but lack diagnostic capabilities for dynamic vibration signals.
2. The “PROX OUT” signal requires isolation for test equipment to maintain machinery protection integrity.

Specifications

Electrical:

• Input: Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.
• Power: Requires +12 to +35 Vdc input.
• 4 to 20 mA Signal Output: 4 to 20 mAdc over specified full-scale range in 2-wire configuration.
• 4 to 20 mA Loop Accuracy: Within ±1.5% over specified full-scale range.
• Probe Gap: Must be gapped between 0.5 and 1.75 mm for full-scale range.
• Maximum Loop Resistance: 1,000 Ω including cable.
• Current Limiting: 23 mA typical.
• Zero and Span: Non-interacting external adjustments.
• NOT OK/Signal Defeat: Signal output goes to less than 3.6 mA within 100 µs after a Not OK condition occurs.
• Power-up Inhibit: Signal output stays at less than 3.6 mA (NOT O.K.) for 2 to 3 seconds after power is applied.

Proximitor Sensor Output:

• Compatible with ungrounded, portable test equipment.
• Output Impedance: 10 kΩ calibrated for a 10 MΩ load.
• Prox Out Linear Range: 1.4 mm, begins at approximately 0.25 mm from the target surface.
• Prox Out Incremental Scale Factor: 7.87 mV/µm typical.
• Temperature Stability: ±10% from 0°C to +70°C.
• Frequency Response: 5 Hz to 6,000 Hz +0, -3 dB.
• Minimum Target Size: 9.5 mm diameter.
• Leadwire Length: Maximum 3 meters for Proximitor Sensor Output.

Electrical Classification:

• General Purpose Approval by CSA/NRTL/C in North America and by VDE in Europe.
• EMC Standards: EN 61000-6-2, EN 55011/CISPR 11, EN 61000-6-4.
• EMC Directive 2004/108/EC.
• Electrical Safety Standards: EN 61010-1.
• Low Voltage Directive 2006/95/EC.

Hazardous Area Locations:

• Non-Hazardous (Zone 2 or Div 2): 13 km maximum between transmitter and receiving device for signal output.
• Intrinsically Safe: 68 meters maximum between transmitter and receiving device for signal output.