Bently Nevada 3500/42-01-02 Proximitor Seismic Monitor

Product Overview

The Bently Nevada 3500/42-01-02 provides continuous machinery protection for critical rotating equipment operating in hazardous environments. This monitor tracks vibration and position parameters from up to four transducers, then compares these values against user-configured alarm setpoints. When parameters exceed set limits, the module triggers appropriate alerts to protect valuable machinery assets.

The -01 I/O module type incorporates internal terminations optimized for Seismoprobe sensors. The -02 agency approval option certifies this module for use in Class 1, Zone 2 hazardous locations under ATEX, IECEx, and CSA standards. The monitor does support Prox/Accel and Velomitor transducers, although Bently Nevada does not recommend these for optimal performance with this particular I/O version. This design accommodates various transducer types while maintaining hazardous area compliance.

Input Specifications

The 3500/42-01-02 accepts signals from one to four proximity, velocity, or acceleration transducers. Typical power consumption measures 7.7 watts. The standard I/O provides an input impedance of 10 kΩ for both Proximitor and acceleration inputs.

Sensitivity options vary by measurement type. For radial vibration, thrust, and eccentricity measurements, users can select either 3.94 mV/μm or 7.87 mV/μm. Acceleration inputs operate at 10 mV/(m/s²). Velocity inputs offer multiple scaling choices, including 20 mV/(mm/s) pk, 5.8 mV/(mm/s) pk, or 4 mV/(mm/s) pk.

The -01 I/O module specifically supports Seismoprobe sensors, which are velocity-type seismic transducers. While the module does support Prox/Accel and Velomitor sensors, Bently Nevada recommends using Seismoprobe sensors for optimal performance with this I/O version. Users should select the appropriate transducer type during configuration.

Signal Conditioning and Filtering

The 3500/42-01-02 offers sophisticated signal conditioning capabilities. For radial vibration measurements, the direct filter is user-programmable with a single-pole -3 dB point ranging from 4 Hz to 4000 Hz. The gap filter provides -3 dB at 0.09 Hz. The 1X vector filter remains valid for machine speeds from 240 cpm to 60,000 cpm.

Specialized filtering options include the Not 1X filter, which achieves a minimum stopband rejection of -34.9 dB. Additionally, the 1X and 2X vector filters attain a minimum rejection of -57.7 dB. These filters effectively remove unwanted frequency components, ensuring accurate vibration analysis.

Accuracy specifications remain consistent across measurement types. Direct and gap measurements achieve ±0.33% of full-scale typical and ±1% maximum. The Smax measurement maintains ±5% maximum accuracy. For acceleration measurements, 4-pole filter designs serve both high-pass and low-pass applications. The Velocity II filter quality uses 4-pole high-pass and 2-pole low-pass designs.

Outputs and Status Indication

The front panel features three visual status LEDs. The OK LED illuminates when the monitor operates properly. The TX/RX LED indicates communication activity with other modules in the 3500 rack. The Bypass LED signals when the monitor enters Bypass Mode.

Each channel has a coaxial connector on the front panel that serves as a buffered transducer output. These connectors are short-circuit protected and feature an output impedance of 550 Ω. The transducer power supply delivers -24 Vdc.

The 3500/42-01-02 provides individual +4 to +20 mA recorder outputs for each channel. These outputs are proportional to the monitor's full-scale range. Short circuits on recorder outputs do not affect monitor operation. The voltage compliance ranges from 0 to +12 Vdc across a load resistance of 0 to 600 Ω. Resolution is rated at 0.3662 µA per bit with ±0.25% error at room temperature and ±0.7% error across the temperature range. The update rate is approximately 100 ms or less.

Shaft Absolute Measurements

The 3500/42-01-02 supports shaft absolute measurements through specialized I/O modules. These modules provide one output for each channel group. Each output is short-circuit protected and features an output impedance of 300 Ω.

Shaft absolute measurements include radial vibration, direct, and velocity options. Radial vibration sensitivity can be set to either 3.94 mV/μm or 7.87 mV/μm. Direct measurements offer the same sensitivity choices. Velocity measurements offer multiple scaling options: 20 mV/(mm/s) pk, 5.8 mV/(mm/s) pk, or 4 mV/(mm/s) pk.

For shaft absolute velocity measurements, the peak or peak-to-peak filter is user-programmable from 3 to 4,000 Hz at -3 dB. The filter quality uses 2-pole designs for both high-pass and low-pass applications. The 1X vector filter provides a constant Q design with a minimum stopband rejection of -57.7 dB.

Environmental and Physical Specifications

The monitor operates at +25 ºC (+77 ºF) unless otherwise noted. This module maintains high accuracy across a wide temperature range, ensuring reliable performance in demanding industrial environments. The robust construction suits installation in 3500 series racks commonly found in power generation, oil and gas, and heavy manufacturing facilities.

The monitor module measures 241.3 mm in height, 24.4 mm in width, and 241.8 mm in depth, with a gross weight of approximately 0.91 kg (2.0 lbs). The I/O module with internal barriers measures 241.3 mm x 24.4 mm x 163.1 mm and weighs 0.46 kg (1.01 lb). The module fits standard 3500 series rack slots and is mechanically interchangeable with other modules in the product line.

Installation Guidelines

Installing the Bently Nevada 3500/42-01-02 follows a straightforward process. First, power down the 3500 rack before inserting or removing any module. Next, slide the module into the designated slot until it seats fully. Then, secure the module using the retaining screws on the top and bottom.

The internal terminations on this -01 version allow direct wiring of transducers to the module's I/O connectors. This design simplifies overall installation and reduces termination points. Users can connect Seismoprobe sensors for optimal performance, though Prox/Accel and Velomitor sensors remain compatible.

Users must configure sensitivity settings in the 3500 rack configuration software to match the specific transducers. Proper configuration ensures measurement accuracy and reliable protection. The 3500/42-01-02 works with various Bently Nevada transducers, including 3300 XL and 7200 series proximity probes.

Hazardous Area Compliance

The -02 agency approval option qualifies the 3500/42-01-02 for use in hazardous areas. This module carries ATEX, IECEx, and CSA certifications for Class 1, Zone 2 applications. This approval makes it suitable for installations in oil and gas facilities, chemical plants, and other environments where explosive atmospheres may be present.

The internal termination design contributes to the module's safety certification while maintaining ease of installation. The 3500/42-01-02 provides reliable machinery protection while meeting stringent hazardous area requirements.

Packaging List

The shipment includes the following items:

• 1 x Bently Nevada 3500/42-01-02 Proximitor Seismic Monitor Module

• 1 x Installation and Configuration Manual

• 1 x Standard I/O Connector Kit with internal terminations

Certificates and warranty documents are not included in the packaging list and are handled separately.

Shipping Method: FedEx, UPS, or DHL

Frequently Asked Questions

What is the primary function of the Bently Nevada 3500/42-01-02?

The 3500/42-01-02 serves as a machinery protection monitor. It continuously measures vibration and position parameters from up to four transducers and alerts operators when values exceed set alarm limits.

What makes the 3500/42-01-02 different from other versions?

The "-01" designation indicates this I/O module is optimized for Seismoprobe sensors with internal terminations. The "-02" approval option provides ATEX, IECEx, and CSA certifications for Class 1, Zone 2 hazardous locations.

Can I use Prox/Accel sensors with the 3500/42-01-02?

Yes, the module does support Prox/Accel and Velomitor transducers, but Bently Nevada does not recommend these for optimal performance. For best results, use Seismoprobe sensors with this I/O version.

How do I configure alarm limits for the 3500/42-01-02?

You can configure alarm limits using the 3500 rack configuration software. The software allows you to set danger, alert, and bypass settings for each channel.

Is the 3500/42-01-02 suitable for hazardous area installations?

Yes, the ATEX, IECEx, and CSA Class 1, Zone 2 approvals make this module suitable for hazardous area applications. However, always verify overall system compliance with local safety regulations.