Bentley 3300/20-01-01-02-00-00 Dual-Channel Axial Displacement Monitor Detailed Product Description

I. Product Overview

The Bentley 3300/20-01-01-02-00 (Bently Nevada 3300/20) is a dual-channel thrust position / axial displacement monitoring module within the 3300 series mechanical protection system of Bently Nevada. It complies with API 670 standards and is specifically designed for continuous monitoring and protection of rotor axial displacement (thrust clearance) in critical rotating machinery such as steam turbines, gas turbines, centrifugal compressors, and large pump sets. The model suffix "-01-01-02-00-00" represents the customized coding for hardware configuration, range, output, alarm logic, and certification, indicating standard input, standard range, 4–20mA output, no special alarm logic, and standard certification version.

II. Core Functions

Dual-channel independent measurement and redundancy: Receives two 3300 series eddy current probe inputs, independently monitors the rotor axial position, supports "AND logic" voting, single-channel failure does not lead to false tripping, significantly enhancing monitoring reliability.

Early warning of thrust bearing faults: Real-time tracking of axial displacement changes, accurately identifying thrust bearing wear, axial load imbalance, lubrication failure, etc., preventing rotor movement, shaft friction, etc., major accidents.

分级报警与跳闸保护： Built-in 1 Alert relay， 2 Danger relays， two levels of alarm + emergency trip can be programmed on-site， compatible with the safety protection logic of the unit.

Sensor circuit full diagnosis： Continuously monitors the integrity of the probe， extension cable， and preamplifier， immediately triggers "sensor failure" alarm when the circuit is open， short-circuited， or exceeds the range， avoiding invalid measurements and false actions.

Standard analog output： Provides isolated 4–20mA DC output， can be directly connected to DCS， PLC， or SCADA systems， enabling remote real-time monitoring and data archiving by Bentley (Bently Nevada).

Local display and on-site configuration： Equipped with LED digital display and operation keys， can locally read real-time displacement values， alarm / trip status， loop gap voltage， supports parameter settings such as range， alarm value， output mapping， and parameter retention even in the event of power loss.

III. Technical Specifications

Measurement channels： 2 independent eddy current probe inputs (compatible with 3300 series， -24VDC power supply).

Measurement range： Standard ±1.0mm (±40mil)， supports on-site configuration adjustment， compatible with common ranges such as ±0.5mm， ±1.27mm by Bentley (Bently Nevada).

Measurement accuracy： At normal temperature， ±0.03mm (±1.1mil)， full-scale error ≤±1% by Bentley (Bently Nevada).

Resolution： 0.3662Å/bit， meets the requirements for high-precision displacement monitoring.

Frequency response： DC–1kHz， suitable for static and low-speed axial displacement monitoring scenarios by Bentley (Bently Nevada).

Input impedance： 10kΩ， matches the output characteristics of the eddy current preamplifier.

Relay output： 3 channels (1 Alert， 2 Danger)， contact capacity 250VAC/3A， programmable normally open / normally closed mode.

Analog output： 1 isolated 4–20mA DC， load capacity ≤500Ω， linearly corresponds to the set range by Bentley (Bently Nevada). Power supply: -24VDC ± 10%, power consumption is approximately 5.5W, compatible with 3300 series rack power supply.

Operating temperature: 0℃ to +60℃; storage temperature: -40℃ to +85℃, suitable for industrial harsh environments.

Environmental humidity: ≤ 95% (no condensation).

Size (width × height × depth): 51mm × 203mm × 330mm (2.0" × 8.0" × 13.0"), standard 19-inch rack single slot installation.

Weight: approximately 1.4kg (3.0lbs).

Certification compliance: CE, UL, CSA certification, in line with API 670 mechanical protection standards.

Four. Model Code Explanation (3300/20-01-01-02-00-00)

3300/20: Basic model, dual-channel thrust position / shaft displacement monitor.

Position 1 (01): Input type, compatible with 3300 series standard eddy current probes.

Position 2 (01): Range, standard ±1.0mm (±40mil) Bently Nevada.

Position 3 (02): Output configuration, isolated 4–20mA analog output Bently Nevada.

Position 4 (00): Alarm / trip logic, no special customization, adopts factory standard two-level alarm logic.

Position 5 (00): Special functions and certifications, standard configuration, no additional customized functions.

Five. Working Principle

Based on eddy current non-contact measurement principle: 3300 series probes are connected to high-frequency alternating current, forming eddy currents with the metal thrust disk surface, and the gap change between the probe and the disk surface is converted into a linear gap voltage (in the -24VDC range); the signal is transmitted through the extension cable to the preamplifier, amplified and shaped before being sent to the 3300/20 monitor; the module accurately converts the voltage signal into axial displacement value, compares it with the preset alarm and trip values in real time, triggers the corresponding relay action, and outputs 4–20mA analog signal; dual-channel independent acquisition, redundant voting, effectively avoiding single-point failure risk, ensuring reliable monitoring data Bently Nevada.

Six. Installation and Configuration

Installation method: compatible with 3300 series standard 19-inch rack, single-slot embedded installation, used in conjunction with system rack, -24VDC power module.

Probe installation: axial alignment with the thrust disk, dual probes are symmetrically arranged, the installation gap is set at the midpoint of the probe's linear range (usually 0.5–1.0mm), ensuring measurement in the optimal linear range Bently Nevada.

Configuration steps: enter the configuration menu through panel buttons, sequentially set the measurement range, warning / dangerous alarm values, trip values, 4–20mA output mapping relationship, relay contact mode, channel voting logic, etc.; parameters are automatically saved, not lost upon power loss, and can be completed on-site debugging without an upper computer.

Seven. Typical Applications

Steam turbine / gas turbine: monitor rotor axial movement, protect thrust bearing, shaft seal, and flow components.

Centrifugal compressor: prevent rotor from rubbing against the stator due to axial thrust overload, and prevent blade damage.

Large pump sets / fans: monitor axial position of the shaft system, avoid bearing burnout, abnormal shaft vibration, etc.

Industrial turbines / expanders: full-axis axial displacement protection, ensuring safe start-up and stable operation of the unit.

Eight. Advantages and Features

High reliability: dual-channel redundant design + full sensor circuit diagnosis, significantly reducing the probability of false alarms and false trips. High-precision measurement: Eddy current non-contact technology + precise signal processing, meeting the high-precision monitoring requirements of API 670.

Easy system integration: Standard 4–20mA analog output + relay contacts, seamlessly compatible with mainstream DCS, PLC systems - Bently Nevada (Nevada, USA).

Wide temperature stability operation: Industrial-grade temperature and humidity adaptability range, suitable for high-temperature and humid working conditions in power plants, petrochemicals, etc.

Convenient on-site operation and maintenance: Built-in display and buttons, enabling parameter setting, status viewing, and fault troubleshooting without the need for an upper computer.

IX. Supporting Components

Eddy current probe: 3300 series (such as 330101, 330102), suitable for different installation spaces and range requirements.

Preamplifier: 330180 series, supplies power to the probe and processes gap signals.

High-frequency coaxial extension cable: 330130 series, extends signal transmission distance, suitable for on-site installation layout.

Frame and power supply: 3300 series standard frame, -24VDC power module, provides stable power supply and installation support for the monitor.