The Bently Nevada 991-25-XX-01-CN, also cataloged as the 991-25-XX-01-CN 991 Thrust Transmitter, operates as a dedicated hardware component for axial shaft position measurement within Bently Nevada TSI monitoring systems.
Hardware Specifications
Parameter
Specification
Model
991-25-XX-01-CN
Brand
Bently Nevada
Product Type
Thrust Transmitter
Origin
USA
Weight
0.44 kg
Dimensions
7.3 x 5 x 10 cm (estimated shipping size)
Input
1 non-contacting 3300 NSv Proximity Probe and extension cable
Output Signal
4-20 mA proportional thrust position signal
Power Supply
+12 to +35 VDC input at transmitter terminal
Maximum Loop Resistance
1,000 ohm including cable at 35 VDC
Current Limiting
23 mA typical
Zero Adjustment
External non-interacting adjustment
Span Adjustment
External non-interacting adjustment
Full Scale Option
25-0-25 mils
System Length Option
5.0 meters (16.4 feet)
Mounting Method
35 mm DIN-rail clips
Eddy-Current Probe Signal Scaling and Rotor Position Measurement
The 991-25-XX-01-CN receives displacement signals from a 3300 NSv eddy-current proximity probe system and converts the probe output into a proportional 4-20 mA transmission signal. The transmitter processes shaft axial movement based on the probe gap relationship and provides continuous thrust position data for TSI monitoring applications.
The eddy-current probe scaling circuit maintains signal conversion between the probe displacement range and transmitter output range. External zero and span adjustments allow field calibration without interaction between the two settings.
The system architecture supports mechanical condition monitoring by measuring rotor axial position changes. Proper probe installation, gap voltage validation, and signal cable routing are required to maintain measurement accuracy and reduce electrical interference.
Frequently Asked Questions
Q: What type of sensor input does the 991-25-XX-01-CN accept? A: The transmitter accepts one non-contacting 3300 NSv Proximity Probe with matching extension cable for axial displacement measurement.
Q: What power supply range is required for operation? A: The transmitter requires a +12 to +35 VDC input connected at the transmitter terminal.
Q: How is the output signal adjusted during commissioning? A: Zero and span calibration are performed through external non-interacting adjustment controls on the transmitter.
Field Installation Guidelines
Install the transmitter on a suitable 35 mm DIN rail mounting system using the supplied DIN-rail clips.
Connect the 3300 NSv proximity probe and extension cable according to the Bently Nevada installation documentation.
Maintain proper cable routing separation from high-current power conductors to reduce electromagnetic interference.
Verify probe wiring polarity and shield termination before system energization.
Perform zero and span calibration after mechanical installation and confirm the 4-20 mA output corresponds with the required thrust position range.
Ensure the DC supply voltage remains within the specified +12 to +35 VDC operating range.
