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.