Description
Detailed parameter table
| Parameter name | Parameter value |
| Product model | 3500/70M |
| Manufacturer | Bently Nevada |
| Product category | Recip Impulse Velocity Monitor |
| Series affiliation | 3500 Machinery Protection System |
| Input channels | 4-channel input |
| Input type | Accepts input from seismic transducers, accelerometers, proximity probes |
| Signal range | 10 – 100 mV rms (proximity probe signals) |
| Frequency range | 3 – 30,000 Hz |
| Accuracy | ±0.5% of reading |
| Resolution | 0.1 mils/sec |
| Output signals | 4 analog output signals (0 – 10 V or 4 – 20 mA), 4 digital output signals (dry contact) |
| Alarm relay outputs | 4 alarm relay outputs (dry contact) |
| Communication ports | RS – 232, RS – 485, Ethernet |
| Power requirements | 120 or 240 VAC, 50/60 Hz |
| Operating temperature | 0°C to 55°C (32°F to 131°F) |
| Storage temperature | -20°C to 70°C (-4°F to 158°F) |
| Form factor | Rack mount (suitable for 3500 system) |
| Dimensions | 241.3 mm (H) × 24.4 mm (W) × 241.8 mm (D) (9.50 in × 0.96 in × 9.52 in) |
| Weight | 0.91 kg (2.0 lb) |
| Protection features | Built – in alarm relays, channel isolation, overvoltage protection |
| Certification | Complies with relevant industrial standards |
| Configuration software | 3500 rack configuration software |
BENTLY 3500/70M
Product introduction
The 3500/70M by Bently Nevada is a 4-channel Recip Impulse Velocity Monitor, playing a crucial role within the 3500 Machinery Protection System. Engineered specifically for reciprocating compressor applications, this monitor is tasked with meticulously monitoring the vibration of compressor crankcases and crossheads. It serves as a vigilant sentinel, safeguarding the integrity of reciprocating compressors by providing continuous and accurate vibration data.
The monitor receives input from a variety of sensors, such as seismic transducers, accelerometers, and proximity probes. Once the signals are received, the 3500/70M undertakes a series of conditioning processes. It extracts meaningful vibration measurements from the raw input, which are then compared against user-programmable alarm thresholds. This comparison forms the basis for generating timely alerts when abnormal vibration levels are detected, ensuring that potential issues are nipped in the bud before they escalate into major problems.
Each channel of the 3500/70M is highly configurable using the 3500 rack configuration software. This flexibility allows it to perform functions like impulse acceleration, acceleration², recip velocity, and low-frequency recip velocity calculations. By generating these various parameters, also known as static values, the monitor offers a comprehensive view of the compressor’s operational state, equipping both operations and maintenance personnel with essential machine information.
Core advantages and technical highlights
Multi-channel monitoring for comprehensive coverage
With its 4-channel design, the 3500/70M can simultaneously monitor multiple critical points on a reciprocating compressor. This multi-channel approach provides a holistic view of the compressor’s vibration profile, enabling the detection of complex vibration patterns that might be missed with a single-channel solution. For example, it can monitor the vibration of different crossheads or crankcase sections simultaneously, ensuring that no potential problem area goes unnoticed.
Versatile sensor compatibility
The ability to accept inputs from seismic transducers, accelerometers, and proximity probes makes the 3500/70M incredibly versatile. This compatibility allows it to be integrated into a wide range of existing sensor setups, regardless of the sensor technology in use. Whether it’s a new installation or a retrofit project, the monitor can easily interface with different sensors, reducing the need for costly sensor replacements or system overhauls.
High accuracy and resolution
Boasting an accuracy of ±0.5% of reading and a resolution of 0.1 mils/sec, the 3500/70M delivers highly precise vibration measurements. This level of accuracy is crucial for detecting even the slightest deviations in compressor vibration, which could be early indicators of component wear, misalignment, or other mechanical issues. The high-resolution measurements enable detailed analysis of vibration patterns, facilitating more accurate fault diagnosis and predictive maintenance planning.
Advanced alarm and communication capabilities
Equipped with 4 analog output signals (0 – 10 V or 4 – 20 mA), 4 digital output signals (dry contact), and 4 alarm relay outputs (dry contact), the 3500/70M can effectively communicate the compressor’s status to other systems. The analog and digital outputs can be used to transmit vibration data to a central control room for monitoring and analysis, while the alarm relay outputs can be configured to trigger immediate actions, such as shutting down the compressor or activating an alarm system, when critical vibration thresholds are crossed. Additionally, its RS – 232, RS – 485, and Ethernet communication ports enable seamless integration with modern industrial networks, allowing for remote monitoring and control.
BENTLY 3500/70M
Typical application scenarios
Oil and gas production
In oil and gas production facilities, reciprocating compressors are used to boost the pressure of gases during extraction, transportation, and processing. The 3500/70M is deployed to monitor the vibration of these compressors, ensuring their reliable operation. By detecting early signs of vibration issues, it helps prevent unplanned downtime, which could lead to significant production losses. For instance, it can identify when a compressor’s crosshead is experiencing abnormal vibration due to worn bearings, allowing maintenance teams to schedule repairs before a catastrophic failure occurs.
Chemical processing
Chemical plants rely on reciprocating compressors for various processes, such as gas compression for chemical reactions. The 3500/70M plays a vital role in these plants by continuously monitoring compressor vibration. In a chemical processing environment, where the consequences of compressor failure can be severe, both in terms of safety and production disruption, the monitor’s ability to provide accurate and timely vibration data is invaluable. It enables operators to maintain optimal compressor performance, ensuring the smooth running of chemical processes and minimizing the risk of costly shutdowns.
Power generation
In power generation plants, reciprocating compressors are used for applications like gas supply for combustion engines or air compression for power generation processes. The 3500/70M is installed to monitor the vibration of these compressors, contributing to the overall reliability of the power generation system. By detecting and alerting operators to potential vibration-related problems, it helps prevent compressor failures that could disrupt power supply. For example, it can detect abnormal vibration in a compressor used to supply gas to a gas turbine, allowing for timely maintenance and ensuring stable power generation.
Refrigeration
Reciprocating compressors are commonly used in large-scale refrigeration systems, such as those in cold storage facilities and industrial refrigeration plants. The 3500/70M monitors the vibration of these compressors to ensure efficient cooling operation. In a refrigeration system, any disruption in compressor performance can lead to temperature fluctuations, spoilage of stored goods, or increased energy consumption. The monitor’s ability to provide real-time vibration data helps maintenance teams proactively address any issues, ensuring the reliable operation of the refrigeration system and protecting the integrity of the stored products.
Pipeline compression
In pipeline transportation, reciprocating compressors are used to maintain the pressure of gases or liquids flowing through the pipelines. The 3500/70M is utilized to monitor the vibration of these compressors, ensuring the continuous and efficient operation of the pipeline system. By detecting and preventing vibration-related problems, it helps avoid pipeline blockages, leaks, or other issues that could disrupt the transportation of valuable resources. For example, it can detect abnormal vibration in a compressor used to compress natural gas for long-distance pipeline transmission, allowing for timely maintenance and ensuring the uninterrupted flow of gas.
Related model recommendations
125680-01 (Bently Nevada): Vibration transmitter that can be integrated with the sensor inputs of 3500/70M for enhanced vibration data collection.
133396-01 (Bently Nevada): Accelerometer system whose outputs can be fed into the 3500/70M for accurate vibration measurement.
3500/34 (Bently Nevada): Communication gateway that can be used to transmit the vibration data from 3500/70M to other systems for further analysis and control.
3500/05-01-02-00-00-01 (Bently Nevada): Power supply module that provides the necessary power for the 3500/70M to operate.
3500/20 (Bently Nevada): System rack in which the 3500/70M can be mounted, providing a stable and organized housing for the monitor.
140471-01 (Bently Nevada): Signal conditioning module that can be used to pre-condition the sensor signals before they are fed into the 3500/70M, ensuring optimal signal quality.
330130-080-00-00 (Bently Nevada): Calibration fixture for verifying and calibrating the accuracy of the 3500/70M, ensuring reliable measurement results.
3500/60 (Bently Nevada): Display module that can be used to visualize the vibration data collected by the 3500/70M, making it easier for operators to monitor and analyze the compressor’s condition.
Installation, configuration and maintenance instructions
Installation preparation
Before installing the 3500/70M, it is essential to verify its compatibility with the existing 3500 system components. Ensure that the rack where it will be mounted has an available slot and that the power supply, such as the 3500/05-01-02-00-00-01, can support the additional load. Gather the necessary tools, including a screwdriver set, torque wrench, and a laptop with the 3500 rack configuration software installed. Thoroughly inspect the module for any signs of shipping damage, paying close attention to the connectors and the front panel indicators.
Mounting and wiring
Insert the 3500/70M into an appropriate slot in the 3500 system rack, such as the 3500/20 rack, and secure it using the provided front panel screws, torquing them to the specified values. Power is typically supplied through the rack backplane, eliminating the need for separate external power wiring. Connect the sensor inputs, such as those from seismic transducers, accelerometers, or proximity probes, to the appropriate terminals on the 3500/70M using shielded twisted-pair cable. For the output connections, use appropriate cables to connect the analog, digital, and alarm relay outputs to the receiving devices, such as a central control system or an alarm annunciator. Ensure proper grounding of the cable shields at the module end only to prevent ground loops, which could introduce noise and affect the accuracy of the measurements.
Configuration procedures
Power on the 3500 system and establish communication with the 3500/70M using the 3500 rack configuration software. Configure each channel according to the type of sensor connected, specifying parameters such as input type (e.g., seismic transducer, accelerometer), signal range, and frequency range. Set the scaling parameters to convert the raw input signals into meaningful engineering units, such as mm/s for velocity or g for acceleration. Define the alarm thresholds for each channel, including both alert setpoints for normal operating deviations and danger setpoints for critical conditions. Configure the communication settings for the RS – 232, RS – 485, or Ethernet ports, ensuring seamless data transmission to other systems. After configuring all the parameters, save and backup the configuration settings to prevent data loss in case of system failures or upgrades.
Maintenance suggestions
Include the 3500/70M in regular system inspections, preferably quarterly. During these inspections, verify that the front panel indicators are showing normal operation. Check the system diagnostics for any error codes that could indicate channel faults, communication issues, or sensor problems. Periodically, during scheduled shutdowns, use the 330130-080-00-00 calibration fixture to verify the accuracy of the monitor. Inject known signals into each channel and compare the measured values with the expected results, adjusting the calibration as necessary. Clean the ventilation openings of the module regularly to ensure proper cooling, especially in dusty or dirty environments. Stay updated on firmware releases for the 3500/70M and apply any relevant updates during maintenance windows to enhance performance, fix bugs, and ensure compatibility with other system components, such as the 3500/34 communication gateway.
Service and guarantee commitment
Bently Nevada offers a 12 – month warranty for the 3500/70M, covering manufacturing defects and performance issues that occur under normal operating conditions. This includes ensuring the accuracy of vibration measurements, the proper functioning of alarm relays, and the integrity of communication ports. The company’s technical support team is readily available to provide expert guidance on installation, configuration, and integration with other Bently Nevada products, such as the 125680-01 vibration transmitter and 133396-01 accelerometer.
For customers seeking in – depth knowledge, Bently Nevada provides specialized training on the principles of reciprocating compressor vibration monitoring, the operation of the 3500/70M, and troubleshooting techniques. Beyond the warranty period, the company offers service agreements that include calibration verification, performance testing, and expedited replacement services to minimize downtime. With a global network of service professionals and application engineers, Bently Nevada is committed to ensuring that the 3500/70M delivers reliable and accurate vibration monitoring throughout its operational lifecycle, providing customers with peace of mind and enhanced equipment protection.
