Bently Nevada 991-25-50-02-00 Thrust Transmitter

The 991-25-50-02-00Thrust 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 axial displacement (thrust) signal as the input to their machinery control system.

The transmitter is a 2-wire, loop-powered device that accepts input from our 3300 NSv proximity probe and its matching extension cable (available in 5 m and 7 m system length options).  The transmitter conditions the signal into appropriate engineering units proportional to the shaft’s axial position1, and provides it as a 4 to 20 mA industry-standard signal for input to the control system where machinery protection alarming.

The 991-25-50-02-00 transmitter provides the following notable features: Integrated Proximitor Sensor requires no external unit l Non-isolated “PROX OUT " and "COM" terminals plus a coaxial connector provide a dynamic vibration and gap voltage signal output. 

Non-interacting zero and span potentiometers under the Transmitter label supports loop adjustment. l Test Input pin allows quick verification of loop signal output, using a variable DC voltage source 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.

991-25-50-02-00 Potted construction for high humidity (up to 100% condensing) environments.

Thrust transmitters have many limitations when compared to a continuous monitoring system.  They are a practical solution in some applications for measuring rotor axial position and are a valuable tool for trending thrust readings. 

991-25-50-02-00 While the transmitter is capable of alarming on thrust position and nonOK checking, monitor functions such as Timed OK channel defeat, Danger Bypass, and Trip Multiply cannot be used. In addition, PLCs attached to the thrust transmitter are not suitable for plantwide diagnostic systems such as System 1 or Rule Paks.

Transmitter Temperature 

Operating Temperature -35 °C to +85 °C (-31 °F to +185 °F)

Storage Temperature -51 °C to +100 °C (-60 °F to +212 °F).

Probe Temperature

Operating Temperature -35 °C to +177 °C (-31 °F to +350 °F).

Storage Temperature -51 °C to +177 °C (-60 °F to +350 °F).

Relative Humidity

100% condensing, non-submerged,with protection of coaxial connectors.