Bently Nevada 990 Vibration Transmitter

The Bently Nevada 990 Vibration Transmitter is intended primarily for the original equipment manufacturers (OEMs) of centrifugal air compressors or small pumps, motors, or fans who prefer to provide a simple 4 to 20 mA proportional vibration signal as the input to their machinery control system.

The 990 vibration transmitter is a 2-wire, loop-powered device that accepts input from Bently Nevada’s 3300 NSv proximity probes and a matching extension cable (available in 5 m and 7 m system length options). The transmitter conditions the signal into appropriate peak-to-peak vibration amplitude engineering units, and provides this value as a proportional 4 to 20 mA industry-standard signal as the input to the control system where machinery protection alarming and logic occurs.

Bently Nevada 990 Vibration Transmitter Specifications
Input

Features

• Integrated Proximitor Sensor requires no external unit
• Non-isolated “PROX OUT” and “COM” terminals plus a coaxial connector to provide a dynamic vibration and gap voltage signal output for diagnostics
• Non-interacting zero and span potentiometers under the Transmitter label supports loop adjustment
• Test Input pin for quick verification of loop signal output, using a function generator as the input
• A Power-up Inhibit circuit eliminates signal errors due to line voltage transients
• A Not OK/Signal Defeat circuit prevents high outputs or false alarms due to a faulty proximity probe or loose connection
• Choice of DIN-rail clips or bulkhead mounting screws as standard options simplifies mounting
• Potted construction for high humidity (up to 100% condensing) environments
• Compatibility with 3300 NSv proximity probe allows transducer installation in small areas with minimal clearance, typical of centrifugal air compressors