Product Overview
The Bently Nevada 991-06-50-01-00 Thrust Transmitter is a precision industrial automation module designed for continuous axial vibration monitoring. This probe vibration transmitter provides a reliable 4-20 mA output signal proportional to shaft thrust displacement. Part of the 991 series, it accepts a non-contacting 3300 NSv proximity probe and integrates seamlessly into control systems. The model 991-06-50-01-00 offers a full-scale option of 0.6-0-0.6 mm with a 5.0 meter system length. Its DIN rail mounting clip enables fast installation in electrical cabinets.
When axial thrust exceeds safe limits, plant downtime and equipment damage can occur. The 991-06-50-01-00 addresses this with a Not OK/Signal Defeat function that drives the output below 3.6 mA within 100 µs of a fault, quickly alerting operators. This feature makes it a critical component for turbomachinery protection.
Technical Specifications
| Parameter |
Value |
| Full-scale Option |
0.6-0-0.6 mm |
| System Length |
5.0 meters (16.4 feet) |
| Mounting |
35 mm DIN-rail clips |
| Output Signal |
4-20 mA (2-wire) |
| Power Input |
+12 to +35 Vdc at transmitter terminal |
| Linear Range |
0.25 to 1.65 mm for Prox Out |
| Accuracy |
Within ±1.5% of full scale (typical) |
| Maximum Loop Resistance |
1,000 Ω including cable at 35 Vdc |
| Current Limiting |
23 mA typical |
| Zero and Span |
Non-interacting external adjustments |
| Operating Temperature |
-35°C to +85°C (-31°F to +185°F) |
| Storage Temperature |
-51°C to +100°C (-60°F to +212°F) |
| Weight |
0.43 kg (0.9 lbm) |
Industry Applications
The Bently Nevada 991-06-50-01-00 serves in critical rotating machinery such as steam turbines, centrifugal compressors, and large pumps. Its axial measurement capability monitors thrust bearing wear and prevents catastrophic failure. For example, in a turbine generator set, the transmitter provides a 4-20 mA signal to the distributed control system (DCS) for continuous protective monitoring. The Not OK feature ensures rapid response to probe or electronics faults, aligning with API 670 protection standards.
Installation & Setup Guidance
Mount the 991-06-50-01-00 using the included 35 mm DIN-rail clips. Accept a 3300 NSv proximity probe and extension cable (sold separately). Connect power (+12 to +35 Vdc) and loop wiring per the terminal diagram. Adjust zero and span using non-interacting external trimmers. Verify the 4-20 mA output over the specified full-scale range. The transmitter operates in a 2-wire configuration, simplifying field wiring. Ensure loop resistance does not exceed 1,000 Ω at 35 Vdc to maintain accuracy.
Maintenance & Reliability
The 991-06-50-01-00 requires minimal routine care. Inspect the DIN rail connection and probe cable annually. The operating temperature range of -35°C to +85°C suits harsh environments. The Not OK/Signal Defeat feature self-checks the transmitter and probe integrity, enhancing system reliability. Store the module between -51°C and +100°C when not in use. Its 0.43 kg weight and compact design simplify spare parts management.
Selection Guide & Purchasing Advice
Before ordering, verify the required system length (option -50 indicates 5.0 meters) and full-scale range (06 = 0.6-0-0.6 mm). The mounting option 01 provides DIN-rail clips. For compatibility, use only a 3300 NSv proximity probe and extension cable. The agency approval option is 00 (not required). For assistance selecting the correct configuration, contact ubest101, a trusted supplier of Bently Nevada modules like the 991-06-50-01-00.