The 991 series Thrust Transmitter Bently Nevada 991-01-XX-01-00 MOD：288865-01 Transmitter is a loop-powered 4-20 mA thrust transmitter. It converts signals from a 3300 NSv proximity probe for axial displacement monitoring.

Application

Centrifugal Compressor OEMs: Primary use for OEMs building compressors requiring a simple thrust monitoring signal.

Small Pump Thrust Monitoring: Provides axial displacement feedback for protection systems on pumps.

Electric Motor Bearing Monitoring: Monitors shaft axial position in motor applications.

Fan Assembly Protection: Used in fan systems to monitor thrust and prevent damage.

Machinery Control Integration: Delivers a standard 4-20mA signal directly to plant control and alarm systems.

High-Humidity Environments: Its potted construction suits installations in condensing atmospheres.

FAQ

Q1: What is the main purpose of this 991 Transmitter?

A1: It is designed for OEMs to provide a simple 4-20 mA proportional signal for monitoring axial displacement (thrust) in machinery like centrifugal compressors and pumps.

Q2: What type of sensor does it work with?

A2: It is specifically compatible with and accepts input from the Bently Nevada 3300 NSv proximity probe and its matching extension cable.

Q3: What is a key feature for signal verification?

A3: It has a Test Input pin that allows quick verification of the 4-20 mA loop output using a variable DC voltage source.

Q4: How does it handle faulty sensor connections?

A4: Its "Not OK/Signal Defeat" circuit prevents false alarms or high output signals caused by a faulty probe or loose connection.

Q5: Is it suitable for humid environments?

A5: Yes, its potted construction allows reliable operation in high-humidity, condensing environments.