Description
Bently Nevada 3500/44M Aeroderivative GT Vibration Monitor
Configured for vibration signal acquisition and alarm-based protection in aeroderivative gas turbine monitoring systems, the Bently Nevada 3500/44M Aeroderivative GT Vibration Monitor (3500/44M vibration monitor) provides direct physical/electrical execution of multi-channel vibration processing across the 3500 Series Machinery Protection System platforms. The module conditions inputs from velocity and acceleration transducers and executes programmable alarm comparison logic per configured machine operating mode.
The unit operates with multimode filtering architecture, supporting integration, 1X tracking, and band-pass vibration analysis. Channel pairs operate with independent Keyphasor references for phase-aligned vibration evaluation under variable turbine speed conditions.
Suffix Breakdown & Model Matrix
No explicit suffix segmentation data is provided for 3500/44M. The model is treated as a fixed module identifier within the 3500 aeroderivative GT monitor family.
Hardware Specifications
| Parameter |
Specification |
| Model |
3500/44M Aeroderivative GT Vibration Monitor |
| Brand |
Bently Nevada |
| Origin |
USA |
| Weight |
0.91 kg |
| Dimensions |
241.3 mm x 24.4 mm x 241.8 mm |
| Power Consumption |
~7.7 W typical |
| Channels |
4 channels (programmable in pairs) |
| Input Types |
Velomitor, accelerometers, Proximitor probes via interface modules |
| Input Impedance |
3.5 MΩ to >95 kΩ depending on sensor type |
| Transducer Supply |
23 VDC nominal, 43 mA max |
| Outputs |
Buffered transducer output, +4 to +20 mA recorder output |
| Filter Modes |
Integration, 1X tracking, band-pass vibration |
| Keyphasor Inputs |
2 independent Keyphasor channels |
Multimode vibration processing and Keyphasor phase correlation
The 3500/44M implements selectable digital filter chains for vibration decomposition across multiple operating conditions. Signal paths support integration-based velocity derivation, 1X synchronous tracking for rotational harmonics, and band-pass filtering for broadband excitation components. Each channel pair can be bound to independent Keyphasor references, enabling phase-resolved vibration vector calculation under variable turbine speed profiles.
Alarm logic supports up to 8 configurable threshold sets per channel pair, allowing condition-specific switching between operational states without hardware reconfiguration. Backplane synchronization maintains deterministic sampling alignment across all channels.
Frequently Asked Questions (FAQ)
Q: Can each channel operate with different filter modes simultaneously?
A: Yes. Each channel pair supports independent configuration of integration, 1X tracking, or band-pass filtering.
Q: Does the module support multiple Keyphasor inputs?
A: Yes. The unit accepts 2 Keyphasor inputs with assignment per channel pair for phase tracking.
Q: Is the module hot-swappable in the 3500 rack?
A: Yes. It supports hot insertion and removal while maintaining backplane continuity.
Field Installation Guidelines
Install the module into a compatible Bently Nevada 3500 rack slot with full backplane engagement. Ensure adjacent modules are properly seated or covered to maintain airflow consistency and mechanical stability.
Use shielded twisted-pair cabling for all transducer inputs. Route low-level vibration signals away from power conductors and switching devices to reduce electromagnetic coupling. Cable shields must be grounded at a single rack-end point.
During commissioning, verify correct sensor type assignment and filter configuration before enabling alarm logic. Incorrect Keyphasor mapping may result in phase tracking errors under variable speed operation.
