Description
The Bently Nevada 3300/20 (Part Number 135322-01) is a specialized Dual Thrust Monitor designed to provide continuous, high-speed monitoring of axial position (thrust) in rotating machinery such as steam turbines, gas turbines, and compressors. As a cornerstone of the 3300 Monitoring System, this unit processes signals from proximity probes to measure the rotor’s axial movement relative to the machine casing. By utilizing dual-channel inputs, it provides redundant protection and trip logic, ensuring the prevention of catastrophic machine damage caused by thrust bearing failure or excessive rotor displacement.

Key Technical Specifications
| Parameter | Value/Description |
| Part Number | 135322-01 |
| Monitor Type | Dual Thrust Position Monitor |
| System Compatibility | Bently Nevada 3300 Series Rack |
| Input Signal | Proximity Probe / Transducer inputs |
| Measurement Range | \pm 0.5 to \pm 2.0 mm (configurable) |
| Logic Configuration | 3300/20-12-01-00-01-00 |
| Revision | Rev. A |
| Frequency Response | DC to 3.0 kHz |
| Output Type | 4–20 mA proportional signal / Alarm Relays |
| Power Input | Rack-fed backplane power |
Recommended Related Models
These components are essential for the operation and integration of the 3300/20 monitoring card within a full protection system:
- 3300/01: System Interface Module (SIM)
- 3300/02: Power Supply Module
- 3300/22: Dual Velocity Monitor
- 3300/25: Keyphasor Module
- 3300/50: Tachometer Module
- 330100: 3300 XL 8mm Proximity Probe (Compatible Sensor)
- 330130: 3300 XL Extension Cable
- 330180: 3300 XL Proximitor Sensor
- 330190: Proximitor Housing
- 125840-01: Spare Relay/Alarm Module (for 3300 series)
Note on Configuration: The model number string
3300/20-12-01-00-01-00contains specific hardware and software option codes. These define the input transducer type, alarm setpoint scaling, and internal logic bypass features. When replacing this unit, ensure the new module is configured to match these specific digit codes to maintain identical machine protection behavior.

