Description
Product Description
The Bently Nevada 3500/70M (P/N 136449-09) is a dedicated reciprocating compressor monitoring module engineered for the 3500 Machinery Protection System. This 4-channel monitor acquires vibration data from seismic transducers and converts the signals into machinery condition parameters used for protection, diagnostics, and process monitoring.
Designed for compressor applications, the module continuously evaluates vibration conditions against configurable Alert and Danger thresholds to support early fault detection and machine shutdown protection. It supports multiple monitoring modes for crankcase, frame, and crosshead vibration analysis in reciprocating machinery environments.
The module integrates signal conditioning, alarm processing, buffered outputs, and recorder outputs within a single rack-based protection platform. Channel pairs can be configured independently for different measurement strategies depending on compressor operating requirements.
Key Features
- Four-channel reciprocating compressor vibration monitor
- Compatible with Bently Nevada 3500 protection racks
- Supports seismic acceleration and velocity transducers
- Continuous machinery protection with configurable alarm logic
- Buffered outputs for external analysis equipment
- Recorder outputs for DCS and PLC integration
- Front-panel diagnostic LED indicators
- Designed for high-reliability industrial compressor systems
Monitoring Functions
Each channel pair can simultaneously perform one or two monitoring functions:
- Impulse Acceleration
- Acceleration 2
- Reciprocating Velocity
- Low-Frequency Reciprocating Velocity
Technical Specifications
| ParameterSpecification |
|
| Product Type |
Recip Impulse Velocity Monitor |
| Model |
3500/70M |
| Part Number |
136449-09 |
| System Compatibility |
Bently Nevada 3500 Series |
| Input Channels |
4 seismic transducer inputs |
| Power Consumption |
7.7 W nominal |
| Acceleration Input Impedance |
10 kΩ |
| Velocity Input Impedance |
1 MΩ |
| Special Inhibit Input |
Contact closure, 5 VDC @ 390 μA |
| Recorder Output Range |
+4 to +20 mA |
| Recorder Load Resistance |
600 Ω maximum |
| Recorder Update Rate |
Less than 100 ms |
| Recorder Resolution |
0.3662 μA |
| Recorder Accuracy |
±0.05 mA typical |
| Buffered Output |
One coaxial connector per channel |
| Buffered Output Impedance |
550 Ω typical |
| Transducer Supply Voltage |
–22 VDC minimum |
| Transducer Supply Current |
40 mA maximum |
| Short Circuit Protection |
Supported |
| Communication Indicators |
OK, TX/RX, Bypass LEDs |
Sensitivity Ranges
| Measurement TypeSensitivity |
|
| Impulse Acceleration |
0.51–11.72 mV/(m/s²) |
| Acceleration 2 |
0.51–11.72 mV/(m/s²) |
| Recip Velocity |
3.54–22.64 mV/(mm/s) |
| Low-Frequency Recip Velocity |
3.54–22.64 mV/(mm/s) |
Physical Specifications
| ItemValue |
|
| Dimensions |
2.6 cm × 25.6 cm × 24.4 cm |
| Weight |
0.85 kg |
| Country of Origin |
USA |
| Mounting Style |
3500 Rack Installation |
Application Areas
The Bently Nevada 3500/70M 136449-09 module is commonly installed in:
- Reciprocating compressors
- Petrochemical processing units
- Natural gas compression stations
- Refinery rotating equipment systems
- Heavy industrial vibration protection systems
- Compressor skid monitoring applications
Operational Notes
Some third-party industrial listings reference additional values such as 220 V operating voltage, 50 kHz frequency response, stainless steel construction, and extended temperature ranges. These specifications are not standard published parameters for the rack module itself and should be validated against official Bently Nevada documentation before project implementation.
FAQ
What machinery is the 3500/70M designed for?
The module is optimized for reciprocating compressors and associated vibration monitoring applications within the Bently Nevada 3500 protection platform.
Can the module provide analog outputs to external systems?
Yes. The unit includes proportional 4–20 mA recorder outputs for connection to PLC, DCS, or plant monitoring systems.
Does the module support real-time machinery protection?
Yes. The monitor continuously compares vibration measurements against configured alarm setpoints and can initiate protection responses through the 3500 system.
