Description
Bently Nevada 3300/20 Dual Thrust Position Monitor Module
The Bently Nevada 3300/20-12-01-01-00-00 also cataloged as the 3300/20 Dual Thrust Position Monitor module, operates as a dedicated hardware component for axial shaft displacement measurement within the Bently Nevada 3300 Series Machinery Monitoring System. It processes dual independent proximity probe inputs to execute continuous thrust position tracking relative to configured bearing clearance limits.
Hardware Specifications
| Parameter |
Specification |
| ModelBrand |
Bently Nevada 3300/20-12-01-01-00-00 |
| Origin |
USA |
| Weight |
1.0 to 1.4 kg |
| Dimensions |
Not specified (3300 Series full-height rack module form factor) |
| OperatingTemp |
0 degC to +65 degC |
| PowerConsumption |
7.7 W nominal |
| Input Channels |
2 independent proximity probe channels |
| Input Signal |
3300 / 7200 Proximitor compatible |
| Frequency Response |
DC to 6.5 kHz (plus 0, minus 3 dB) |
| Accuracy |
plus or minus 1 percent of full scale |
| Output Types |
0 to -10 VDC, +1 to +5 VDC, or 4 to 20 mA |
Eddy-Current Probe Scaling and Gap Voltage Validation
The module processes eddy-current probe signals through calibrated Proximitor interfaces, converting gap-dependent voltage into axial displacement values. Nominal scaling supports 200 mV/mil or approximately 7.87 V/mm depending on configured transducer type.
Gap voltage monitoring is continuously evaluated against expected operating windows, with front-panel indication used to confirm probe-to-target clearance integrity. The system supports validation against negative voltage excursion limits typically associated with thrust position reference baselines (including -10 VDC domain scaling in full-scale configurations).
Signal integrity is maintained through cross-channel comparison logic, reducing susceptibility to probe degradation, cable attenuation, or electromagnetic coupling effects between adjacent monitoring paths.
Frequently Asked Questions
Q: Can the 3300/20 operate in hot-swap condition within a live rack system?
A: The module is designed for insertion in a powered 3300 Series rack, but hot-swap procedures require channel isolation and adherence to system rack maintenance sequencing to avoid transient alarm states.
Q: How does the module handle dual-channel disagreement in axial position readings?
A: The system supports configurable AND/OR voting logic. In thrust applications, 2-out-of-2 AND logic is typically used to prevent single-channel drift from triggering false trip conditions.
Q: What is the effect of backplane loading on measurement accuracy?
A: Backplane power consumption is fixed at nominal 7.7 W. Electrical loading does not directly affect analog scaling but unstable rack power conditions may introduce signal reference drift across channels.
Field Installation Guidelines
Shielded coaxial connections must be used between proximity probes and Proximitor interfaces, with shield termination grounded at a single point to avoid ground loop interference. Probe gap calibration should be verified prior to commissioning using stable mechanical reference targets.
Module insertion should follow rack power isolation procedures recommended for the 3300 Series backplane architecture. Channel wiring separation is required to maintain cross-talk suppression between dual measurement paths.
Proximity probe tip alignment must remain within manufacturer-specified linear operating range to ensure valid eddy-current response. Mechanical mounting stability of probe brackets directly impacts long-term axial position stability and noise floor performance.
