Product Description

The 3500/42E (Part Number 285691-01) is a high-performance, 4-channel machinery protection module designed for the Bently Nevada 3500 Series Rack. As an "Encore" series module, it is specifically engineered to provide a seamless upgrade or replacement path for legacy vibration monitoring systems while maintaining full compatibility with modern Proximitor* proximity sensors and seismic transducers. The 3500/42E continuously processes signals to provide critical radial vibration, thrust position, and differential expansion measurements for high-speed rotating machinery.

Each channel of the 285691-01 is independently programmable via the 3500 Rack Configuration Software, allowing it to perform specialized functions such as shaft absolute measurement, eccentricity, acceleration, and velocity monitoring. The module compares conditioned signals against user-defined Alert and Danger setpoints, providing real-time machinery protection. This ensures early detection of mechanical issues like imbalance, misalignment, and bearing wear in turbines, compressors, and large industrial pumps. Its high sampling rate and dynamic range make it a cornerstone for Reliability-Centered Maintenance (RCM) and plant safety protocols.

Technical Specifications

• Model Number: 3500/42E

• Part Number: 285691-01

• Manufacturer: Bently Nevada (Baker Hughes)

• Channel Count: 4 independent channels

• Measurement Modes: Radial Vibration, Thrust Position, Differential Expansion, Shaft Absolute, Eccentricity, Acceleration, Velocity

• Input Signal Acceptance: Proximitor proximity probes, seismic sensors (Velocity/Accelerometers)

• Frequency Response: 0.1 Hz to 10 kHz (sensor dependent)

• Signal Processing: True RMS, Peak, Peak-to-Peak detection; configurable digital filters

• Accuracy: Within ±1% of full-scale range

• Alarms: Programmable Alert and Danger thresholds for each channel

• Buffered Outputs: Front-panel coaxial connectors for dynamic signal analysis

• Data Output: 4–20 mA current loops and relay contact integration

• Operating Temperature: -30 °C to +65 °C (-22 °F to +149 °F)

• Dimensions: 228 mm x 50 mm x 289 mm

• Net Weight: 1.27 kg

• Certifications: CE, CSA, ATEX (Hazardous Area Rated)

Advanced Application & Reliability

The 285691-01 is essential for high-criticality assets in power plants and petrochemical facilities where unplanned downtime results in significant revenue loss. The module’s ability to handle multiple measurement types—such as switching between radial vibration for journal bearings and thrust position for axial load monitoring—provides engineers with the flexibility to protect diverse machine trains. By integrating the 3500/42E into a 3500 rack, facilities gain a deterministic protection layer that operates independently of the plant DCS, ensuring safety even during network interruptions.

Frequently Asked Questions

Is the 3500/42E compatible with older 3500 rack backplanes?

Yes, the 285691-01 is designed to fit standard 3500 Series racks. However, you should verify that your 3500 Rack Configuration Software version supports the 42E "Encore" firmware.

Does this module include the I/O module?

The 285691-01 typically refers to the main monitor module. Depending on your wiring requirements (internal or external termination), you may require a specific I/O module such as the 128229-01 or 128240-01.