Product Overview
The Bently Nevada 991-06-50-02-01 is a precision Probe Vibration Transmitter designed for continuous monitoring of axial shaft thrust in rotating machinery. This industrial automation module converts proximity probe signals into a 4-20 mA output, enabling seamless integration with PLCs and DCS systems. With a rugged design and built-in fault detection, the 991-06-50-02-01 ensures reliable operation even in harsh environments.
Technical Specifications
The following table highlights the key parameters of the Bently Nevada 991-06-50-02-01:
| Parameter |
Value |
| Output Signal |
4-20 mA |
| Power Requirement |
+12 to +35 Vdc |
| Linear Range (Prox Out) |
0.25 to 1.65 mm |
| Full-Scale Option |
0.6-0-0.6 mm |
| Loop Accuracy |
±1.5% typical |
| Max Loop Resistance |
1,000 Ω at 35 Vdc |
| Current Limiting |
23 mA typical |
| Operating Temperature |
-35°C to +85°C |
| Storage Temperature |
-51°C to +100°C |
| Weight |
0.43 kg (0.9 lbm) |
| Mounting |
DIN rail |
| Input |
1 non-contacting 3300 NSv probe |
| Agency Approval |
CSA Division 2 |
The Bently Nevada 991-06-50-02-01 offers non-interacting zero and span adjustments, and its Not OK/Signal Defeat function forces the output below 3.6 mA within 100 µs of a fault, ensuring prompt system alerts.
Industry Applications
The 991-06-50-02-01 is ideal for axial thrust monitoring in turbines, compressors, and large pumps. In a steam turbine installation, the transmitter's 0.6-0-0.6 mm range detects thrust bearing wear early, preventing catastrophic failure. Its 4-20 mA output interfaces directly with most PLC-based protection systems. The fault detection feature is critical in remote or unattended locations, as the output drops immediately upon sensor or wiring issues.
Installation & Setup
Mount the Bently Nevada 991-06-50-02-01 on a standard DIN rail. Connect a 3300 NSv proximity probe and extension cable to the input terminals. Wire the 4-20 mA loop in a two-wire configuration; ensure the power supply provides +12 to +35 Vdc. Adjust zero and span using the non-interacting external potentiometers. For bulkhead mounting (option 02), use the provided screws. Verify loop resistance stays below 1,000 Ω to maintain accuracy.
Maintenance & Reliability
The 991-06-50-02-01 is designed for minimal maintenance. Periodically inspect connections and ensure the operating temperature stays within -35°C to +85°C. The Not OK/Signal Defeat function provides self-diagnostics: if the transmitter detects an internal fault, it forces the output below 3.6 mA. This feature reduces downtime by alerting operators before a minor issue escalates. The robust enclosure and CSA Division 2 rating ensure reliable operation in hazardous areas.
Selection Guide
When ordering the Bently Nevada 991-06-50-02-01, specify the full-scale option (06 for 0.6-0-0.6 mm), system length (5.0 meters), mounting (02 bulkhead screws), and agency approval (01 CSA Division 2). This transmitter is available from PLC Source PRO (ubest101) as a new unit. Verify that your probe and cable are compatible with the 3300 NSv series. For additional support, consult the product datasheet.