Description
Bently Nevada 3300/20-12-01-01-00-01
Product Introduction
Bently Nevada 3300/20-12-01-01-00-01 is a dual-channel thrust position monitor from the Bently Nevada 3300 Monitoring System. It continuously monitors axial rotor position through two independent channels, designated Channel A and Channel B. The 3300/20 is specifically designed for thrust-position protection rather than general vibration measurement. Bently Nevada’s operation manual describes thrust position as the rotor’s axial position, or change in axial position, relative to a fixed reference. The monitor provides two-channel monitoring for applications where axial movement must be detected before it develops into mechanical damage.
The Bently Nevada 3300/20-12-01-01-00-01 configuration is identified with a 1–0–1 mm full-scale measurement range. Field equipment records for this exact part number identify buffered transducers, a 7200 system with 200 mV/mil scale factor, and a +4 to +20 mA recorder output. These details are important because the 3300/20 family contains multiple range and output configurations; the base model number alone does not establish the correct replacement.
The Bently Nevada 3300/20-12-01-01-00-01 belongs to an older rack-based machinery protection architecture. Its protection logic includes OK, Alert, Danger, and Bypass status functions, with configurable voting arrangements documented for the dual-channel monitor. The manual describes AND voting for redundant protection and OR voting where the two thrust channels are used independently. This makes the exact configuration of the monitor, transducers, rack, wiring, and alarm logic part of the replacement assessment.
Technical Specifications
| Specification | Details |
|---|---|
| Product Model | 3300/20 |
| Complete Part Number | 3300/20-12-01-01-00-01 |
| Manufacturer | Bently Nevada |
| Product Type | Dual Thrust Position Monitor |
| Product Series | 3300 Monitoring System |
| Measurement Channels | 2 |
| Channel Designation | Channel A / Channel B |
| Measurement | Axial rotor/thrust position |
| Full-Scale Range | 1–0–1 mm |
| Transducer Configuration | Buffered transducers |
| Scale Factor | 7200 system, 200 mV/mil |
| Recorder Output | +4 to +20 mA |
| Alarm Functions | OK, Alert, Danger, Bypass |
| Protection Logic | Configurable channel voting |
| Installation | 3300 rack system |
| External Communication | Not a network controller; analog/relay monitoring architecture |
| Power | Supplied through the 3300 rack |
| Operating Temperature | Verify against the applicable 3300 system installation documentation |
| Protection Rating | Not applicable as a standalone field enclosure |
| Configuration | Hardware/program options must match the existing 3300 system |
The exact 1–0–1 mm range is supported by records for the 3300/20-12-01 configuration family, while the exact requested part number is documented in field listings with the 1–0–1 mm range, buffered-transducer configuration, 7200/200 mV/mil scale factor, and +4 to +20 mA recorder output.
3300/20-12-01-01-00-01
Main Features and Engineering Considerations
Dual-channel thrust protection
The primary purpose of the 3300/20 is continuous axial-position monitoring. Two channels allow the system to compare or vote on thrust-position information rather than relying on a single measurement. The Bently Nevada manual documents both AND voting for redundant protection and OR voting for applications where the channels operate independently. The selected logic is therefore part of the machine-protection design and should not be changed casually during replacement.
1–0–1 mm measurement configuration
The requested suffix identifies a 1–0–1 mm full-scale configuration. This matters when replacing an existing card because other 3300/20 variants use substantially different ranges. For example, other cataloged configurations include 25–0–25 mil ranges, while the requested unit is associated with the metric 1–0–1 mm range. Substituting a monitor with a different range can change the relationship between probe gap, displayed position, recorder output, and alarm setpoints.
Buffered transducer compatibility
This unit is part of a complete proximity-measurement chain. The monitor should be evaluated together with the installed probe, Proximitor, extension cable, and associated termination. A replacement monitor with the correct front-panel model but an incompatible transducer configuration is not a valid field replacement.
Alarm and protection functions
The 3300/20 provides OK, Alert, Danger, and Bypass indications and associated alarm logic. The manual also documents adjustable alarm setpoints, channel bypass, danger bypass, and self-test functions. These functions are directly relevant to machinery protection because an incorrect setpoint or bypass configuration can change the protective response of the machine.
Recorder output
The exact requested configuration is documented with a +4 to +20 mA recorder output. This output should be checked against the plant’s DCS, recorder, or monitoring-system input before replacement. Do not assume that every 3300/20 configuration uses the same output arrangement.
Legacy-system procurement
The 3300/20 is legacy 3300-series hardware. Current replacement planning should therefore focus on exact configuration matching rather than simply locating another 3300/20 card. Inspect the label, PWA number, revision, installed option configuration, transducer type, full-scale range, recorder output, and rack position before purchasing a used or surplus unit.
Application Scenarios
Steam and Gas Turbines
Axial rotor movement is a critical parameter in turbine machinery. The dual-channel thrust monitor can provide continuous thrust-position information and alarm/protection functions within the 3300 machinery-protection architecture.
Compressors
Large centrifugal compressors can experience axial movement associated with operating conditions, thrust-bearing loading, or mechanical faults. A properly configured thrust-position monitor can provide an independent protection measurement.
Industrial Pumps
Large rotating pumps with thrust-bearing arrangements can also use axial-position monitoring where machine design requires it.
General Rotating Machinery
The 3300/20 architecture is applicable where a 3300 rack and compatible proximity measurement chain are already installed. It should not be treated as a general-purpose analog input card.
Engineer’s Guide: Field Pitfalls
1. Do not substitute by “3300/20” alone.
The family contains multiple measurement ranges and output configurations. The requested -12-01-01-00-01 configuration matters.
2. Confirm the 1–0–1 mm range.
Do not replace this unit with a 25–0–25 mil configuration simply because both are labeled 3300/20.
3. Verify the transducer chain.
Check the probe, Proximitor, extension cable, termination, and monitor together. Thrust monitoring is a complete measurement system.
4. Preserve alarm setpoints.
Record Alert and Danger setpoints before removing an operating card. Incorrect values can alter machine protection behavior.
5. Check voting logic.
The 3300/20 supports different channel-voting arrangements. Confirm whether the existing machine uses redundant AND logic or independent/OR channel operation.
6. Check recorder output configuration.
The requested unit is associated with +4 to +20 mA recorder output. Verify the receiving system and scaling before commissioning.
7. Inspect the PWA and revision.
The exact monitor part number may coexist with different board revisions. Record the PWA number and revision from the actual hardware before approving a used replacement.
8. Test before returning the machine to service.
A proper verification should include probe-gap simulation or calibrated displacement input, displayed thrust position, recorder output, OK status, Alert/Danger operation, bypass behavior, and channel voting.
Frequently Asked Questions
What is Bently Nevada 3300/20-12-01-01-00-01?
It is a dual thrust position monitor in the Bently Nevada 3300 Monitoring System. The requested configuration is associated with a 1–0–1 mm full-scale range and buffered-transducer inputs.
Is the 3300/20 a vibration monitor?
No. Its primary measurement is axial/thrust position. The 3300 family contains separate vibration monitors, while the 3300/20 is specifically a Dual Thrust Position Monitor.
How many channels does the 3300/20 have?
It has two thrust-position channels, Channel A and Channel B. The manual describes the two channels as suitable for redundant or independent monitoring arrangements.
What is the full-scale range of this exact configuration?
The requested 3300/20-12-01-01-00-01 is documented with a 1–0–1 mm full-scale range.
What output does this configuration provide?
Field records for this exact part number identify a +4 to +20 mA recorder output. Verify the physical unit and plant wiring before using this as the basis for a replacement specification.
Is it a standalone PLC/DCS input module?
No. It is a dedicated machinery-protection monitor designed for the Bently Nevada 3300 rack system. It should be evaluated as part of the complete thrust-monitoring chain rather than as a generic analog input card.
What should be checked before purchasing a replacement?
At minimum, verify the complete part number, PWA number, board revision, measurement range, transducer configuration, recorder output, alarm configuration, voting logic, rack compatibility, and condition of the monitor. For used hardware, functional testing is strongly preferable to visual inspection alone.
