Bentley 3500/42 Proximitors ®/ Earthquake monitoring module

Bentley 3500/42 Proximitors ®/  Earthquake monitoring module

Product Overview

Core functions

3500/42 Proximitor ®/  The earthquake monitoring module is a four channel monitoring device that can receive input signals from a proximity probe and seismic sensors, and achieve monitoring functions such as radial vibration, thrust position, eccentricity, differential expansion, acceleration, and velocity through configuration. Its core function is to drive alarm output by comparing the current machine vibration value with the preset alarm threshold, and provide machine status data for operation and maintenance personnel.

Key Features

TMR architecture: Supports triple modular redundancy (TMR) configuration, avoids single point of failure through a 2 out of 3 voting mechanism, and ensures system reliability.

Flexible configuration: Customize channel types, alarm thresholds, filtering parameters, etc. through 3500 rack configuration software to adapt to different monitoring scenarios.

Real time diagnosis: Built in self checking function, quickly locate faults through LED indicator lights and event logs.

Safety certification: Compliant with standards such as IEC 61508, suitable for hazardous areas (such as Class I, Division 1/2).

Product Architecture and Working Principle

Hardware Architecture

Input module: support multiple I/O modules, including internal terminal, external terminal, TMR terminal and terminal module with barrier, and adapt to different sensor wiring requirements (such as Proximitor, accelerometer, speed sensor).

Signal processing: Each channel integrates filtering, amplification, and digitization circuits, supporting bandpass, high pass, and low-pass filtering, with a configurable frequency response range (such as radial vibration channels supporting 1 Hz to 4000 Hz).

Communication interface: communicates with other modules through the rack backplane, supports serial protocols such as RS-232/485, and can be connected to the upper computer for data monitoring.

TMR redundancy mechanism

Voting logic: In the TMR configuration, three monitoring modules vote 2 out of 3 for the input signal. If the deviation between the output of one module and that of other modules exceeds the set threshold (such as% Comparison), event logging will be triggered.

Input configuration:

Bus configuration: A single non redundant sensor signal is distributed to three modules through the bus.

Discrete configuration: Three redundant sensors are connected to three modules respectively to improve reliability.

Data output and status monitoring

Proportional value output: Output different parameters based on channel type, such as Direct (peak to peak), 1X/2X amplitude, phase lag, etc. for radial vibration; Gap (gap voltage) and Direct (axial displacement) at the thrust position.

Status identification: Feedback module health status, communication status, and alarm events through LED (OK, TX/RX, BYPASS) and event logs (System Event List, Alarm Event List).

Configuration Guide

Software Configuration Tool

Use 3500 Rack Configuration Software for parameter settings, with core configuration items including:

Channel type: Select radial vibration, thrust position, etc. Different types correspond to different filtering and scaling factors.

Full range: For example, radial vibration Direct can choose 0-10 mil pp (peak to peak), and acceleration can choose 0-20 g pk (peak to peak).

Alarm threshold: Set the Alert/Alarm 1 and Danger/Alarm 2 thresholds for each proportional value, and support lag adjustment (e.g., hysteresis is 1/64 of full scale).

Filter parameters: Set the cut-off frequency of the high/low-pass filter (e.g. acceleration channel supports 3 Hz to 30 kHz).

Example of Key Parameter Configuration

Radial vibration channel:

Select a 3300-8 mm Proximitor sensor and set the Scale Factor to 200 mV/mil.

Set the 1X Amplitude full-scale to 10 mil pp, the Alert threshold to 6 mil pp, the Danger threshold to 8 mil pp, and the delay time to 1 second.

Thrust position channel:

The Zero Position voltage is set to -9.75 Vdc (corresponding to the center value of the gap), the full range is set to 25-0-25 mil, and the direction is set to "Forward Probe" (displacement increases when the rotor moves towards the probe).

Key points of TMR configuration

Three monitoring modules need to be installed adjacent to each other and configured with Comparison Voting (if comparing 1X Amplitude, a deviation of 5% is allowed).

Bussed External Termination Block is used for bus configuration, while three independent sensors and terminal blocks are used for discrete configuration.

I/O modules and wiring

Module type and function

Internal terminal module: directly connected to sensors and recorders, suitable for non hazardous areas, wiring should pay attention to electrostatic protection (such as using anti-static wrist straps).

Internal Barrier Module: Integrated Zener Barrier, suitable for explosion-proof areas (such as Class I, Division 1), to restrict energy flow into hazardous areas.

External terminal module: Connect the sensor with a 25 pin cable and the recorder with a 9-pin cable to simplify the internal wiring of the rack.

Wiring specifications

Proximitor sensor: The power supply (PWR) is connected to -24 Vdc, the signal (SIG) is connected to the channel input, and the shielding layer (SHLD) is grounded.

Seismic sensors (such as Velomitor) require series connection of resistors and capacitors (such as 4 k Ω resistors+10 μ F capacitors) for signal conditioning.

TMR wiring: In discrete configuration, three sensors are connected to independent channels of three modules, and in bus configuration, sensor signals are shared through a Bussed Terminal Block.

Maintenance and testing

Regular verification testing

Testing cycle: It is recommended to conduct it once a year. If the equipment is a critical unit or operates in harsh environments, it can be shortened to once every quarter.

Testing equipment: function generator, multimeter, oscilloscope, Keyphasor Multiplier/Diverder, etc.

Test steps (taking radial vibration channel as an example):

Simulate sensor signals (such as a 100 Hz sine wave with a peak to peak value of 2 V).

Verify the display accuracy of proportional values such as Direct and 1X Amplitude (error ≤ ± 1% of full scale).

Trigger Alert/Arm 1 and Danger/Arm 2 thresholds, confirm that the alarm delay time is consistent with the configuration.

Disconnect the input signal and verify the OK state recovery time (Timed OK Channel Defeat set to 30 seconds).

Scale factor and zero position adjustment

Scale Factor: Used to calibrate the linearity deviation of sensors, such as the default 200 mV/mil for 3300-8 mm Proximitors, which can be adjusted by ± 15%.

Zero Position: For channels such as thrust position and eccentricity, adjust the voltage to make the displayed value zero (such as setting the zero position of thrust position to -9.75 Vdc, corresponding to mechanical zero position).

Recorder output verification

The 4-20 mA output should correspond to the full-scale proportional value. For example, when the full-scale is 10 mil pp, 20 mA corresponds to 10 mil pp, and 4 mA corresponds to 0 mil pp, with an error of ≤± 1%.

Troubleshooting

LED fault diagnosis

OK light off: It may be due to module failure, hardware malfunction, or sensor disconnection. Check the power and wiring, restart the module, or replace spare parts.

BYPASS light on: The channel is bypassed by software or the sensor is faulty. Check the Software Switches configuration and confirm that the sensor is in an OK state.

TX/RX light does not flash: communication failure, check the rack backplane connection and serial port parameters (baud rate, data bits).

Analysis of System Event List

Event 11 (Flash Memory Failure): Flash memory failure, module replacement required immediately.

Event 62 (I/O Module Mismatch): The I/O module type does not match the software configuration. Check the module model and reconfigure it.

Event 493 (Kph Lost): Keyphasor signal loss. Check the Keyphasor sensor and wiring to confirm if the speed is within the valid range (60-60000 cpm).

Common alarm handling

Alert/Arm 1 trigger: If the vibration value exceeds the threshold, check whether the machine is unbalanced, misaligned, or has bearing faults.

Trigger of Danger/Arm 2: Emergency stop condition, immediately stop the machine and troubleshoot equipment faults. If the shaft displacement exceeds the limit, it may cause dynamic and static friction.

Technical specifications and ordering information

key parameter

Input impedance: Proximitor channel 10 k Ω, TMR configuration with bus mode 50 k Ω and discrete mode 150 k Ω.

Frequency response: The radial vibration Direct channel supports 1 Hz-4000 Hz, and the acceleration channel supports 3 Hz-30 kHz.

Environmental conditions: Operating temperature -30 ℃~65 ℃ (non barrier module), storage temperature -40 ℃~85 ℃, humidity ≤ 95% non condensing.

Order Parts

Monitor module: 3500/42-01-00 (discrete internal terminal, no authentication), 3500/42-03-01 (TMR external terminal, CSA authentication).

Spare parts: I/O module (such as 128229-01), terminal block (125808-02 Euro style), cable (129525-0010-01, 10 foot assembly cable).

Safety and Compliance

Explosion proof certification: With barrier module supporting Class I, Division 1 (Groups A-D) and EEx ia IIC, suitable for explosive gas environments.

Static protection: When operating the module, wear an anti-static wrist strap and store it in a conductive bag to prevent static electricity from damaging the circuit board.

Maintenance warning: When hot plugging modules, ensure that the rack is powered off to avoid the risk of short circuit or electric shock caused by live operation.