Bentley 3300/45-03-01-01-00 Dual Channel Differential Expansion Monitoring Module Detailed Product Description

I. Product Overview

The Bentley 3300/45-03-01-01-00 is a dual-channel differential expansion (differential expansion) monitoring module of the 3300 series TSI (Turbo Generator Instrumentation) system from Baker Hughes (formerly GE Bentley Nevada), specifically designed for precise online monitoring of the relative axial thermal expansion (differential expansion) between the rotor and the casing of large steam turbines, gas turbines, large compressors, etc. It prevents serious accidents such as dynamic friction, axial rubbing, and unit tripping caused by excessive thermal expansion difference between the rotor and the casing.

The module is a 19-inch standard rack-mounted, hot-swappable design. It can be installed together with modules such as vibration, shaft displacement, casing expansion, and rotational speed, sharing the backplane - 24V DC power supply and system bus. It is compatible with Bentley 3300 series eddy current probes (11mm specification), with dual-channel independent input and dual-path differential expansion measurement. It has built-in dual-level alarm relays (ALERT + DANGER), complies with API 670 standards, and is suitable for high-temperature, high-pressure, and strong electromagnetic interference environments. It is one of the core protection modules for steam turbine safety monitoring.

II. Model Coding Rules (3300/45-AA-DD-BB-CC)

3300: Bentley 3300 modular TSI system, unified rack, centralized power supply, hot-swappable, multi-module mixed installation architecture.

45: Function code, dual-channel differential expansion monitoring module, monitoring the relative thermal expansion between the rotor and the casing.

AA (range / measurement range, 03 = ±0.5 inches / ±12.7mm): 03 corresponds to ±0.5 inches (±12.7mm) differential expansion range.

DD (probe specification / sensitivity, 01 = 11mm, 100mV/mil): Compatible with 11mm eddy current probes, standard sensitivity 100mV/mil.

BB (relay configuration, 01 = dual relays: warning ALERT + danger DANGER).

CC (certification level, 01 = general industrial safety certification, compliant with API 670, CE, UL).

00 at the end: without safety barrier (not applicable in non-explosion-proof areas).

III. Core Functions

1. Dual-channel eddy current probe signal acquisition and independent differential expansion calculation

Supporting the connection of two independent eddy current probes (A/B channels), respectively monitoring the differential expansion at both ends or different positions of the rotor; the dual channels are completely independent, providing redundant measurement to enhance reliability, and also capable of monitoring the differential expansion at two different measurement points. Built-in signal conditioning circuit, compatible with original Bentley 11mm eddy current probes, input signal - 24V DC, input impedance 10kΩ, strong anti-common-mode interference ability, capable of distinguishing real differential expansion changes from probe / circuit faults.

2. High-precision differential expansion measurement

Range: ±0.5 inches (±12.7mm), programmable scaling to adapt to different unit requirements.

Measurement accuracy: ≤±0.1% full scale (25℃), resolution 0.01mm.

Frequency response: DC–10Hz, suitable for slow thermal expansion characteristics.

Probe power supply: -24V DC (±10%), unified power supply on the backplane, supports short-circuit block switching - 18V DC for different probes.

Measurement principle: Eddy current probes monitor the axial end face of the rotor and the gap with the probe, directly converting it into differential expansion value, without the need for a slope surface, making installation more convenient. 3. Two-stage Relay Alarm Output (ALERT + DANGER)

Configure two epoxy resin-sealed SPDT relays, moisture-proof, dust-proof and anti-interference. Dual-channel alarm is independently configured:

ALERT (Warning): Triggered when the differential expansion value approaches the limit, reminding operation and maintenance personnel to pay attention to the thermal expansion trend and adjust the load.

DANGER (Danger): Triggered when the differential expansion value exceeds the limit or the signal is abnormal,联动 the unit interlock protection and emergency shutdown.

Contact specifications： 250V AC/5A， 30V DC/5A. Can directly drive audible and visual alarms， DCS/PLC or interlock circuits.

Alarm threshold and delay： Independent settings for positive and negative direction thresholds， adjustable delay from 0 to 10 seconds， supports locked/non-locked mode， filters instantaneous fluctuations.

4. Front Panel Display and Local Configuration

Display： Dual analog dials + LCD digital window， respectively display the differential expansion values of A/B channels； OK， ALERT， DANGER， BYPASS four groups of LEDs， intuitively display operation， alarm， bypass， and fault status.

Configuration： Keypad-based local programming， no need for upper computer to set range， alarm threshold， delay， probe calibration parameters， channel enable/disable， positive and negative direction definition.

5. Isolation Buffer Signal Output

The rear terminals provide two isolated analog outputs (4–20mA or 0–10V selectable)， independent output for A/B channels， isolated from power supply， input signal by ≥2500V AC， can send two differential expansion quantity signals to recorders， DCS， oscilloscopes or external systems for data recording， trend analysis and fault tracing.

6. Comprehensive Self-Diagnosis and Fault Identification

24-hour real-time monitoring： probe break / short circuit， signal over-limit， power supply abnormal， module hardware failure， probe calibration abnormal； can distinguish real differential expansion anomalies from sensor / circuit faults， panel LEDs clearly indicate fault types， facilitating rapid troubleshooting.

7. Strong Anti-interference and System Integration

Metal shielding shell， electrical isolation between input/output/power supply ≥2500V AC， anti-common-mode interference， suitable for variable frequency drives， transformers， high-voltage cabinets and other strong electromagnetic environments.

Compatible with 3300 series system bus (Type A)， can be connected to System 1 status monitoring software， realize remote configuration， data storage， trend analysis， fault recording and remote access.

IV. Technical Parameters

Measurement Parameters

Monitoring Channels： Dual channels (A/B independent input， dual differential expansion measurement).

Compatible Sensors： Bently 3300 series 11mm eddy current probe (100mV/mil).

Measurement Range： ±0.5 inches (±12.7mm)， programmable scaling.

Measurement Accuracy： ≤±0.1% full scale (25℃)， resolution 0.01mm.

Frequency Response： DC–10Hz.

Input Impedance： 10kΩ， input voltage - 24V DC.

Measurement Principle： Eddy current gap measurement， direct conversion of differential expansion value.

Electrical Parameters

Operating Power Supply： -24V DC (±10%)， backplane power supply； supports short circuit switching - 18V DC.

Power Consumption： Typical 3W， maximum ≤4W.

Relay Output： 2 SPDT (each channel 1)， 250V AC/5A， 30V DC/5A.

Buffer Output： 2 isolated analog signals (4–20mA/0–10V selectable， A/B independent).

Isolation Strength： Input/output/power supply between ≥2500V AC.

Environmental and Mechanical Parameters

Operating Temperature： 0℃~+65℃ (standard type).

Storage Temperature： -40℃~+85℃. Relative humidity: 5%–95% (no condensation).

Installation method: 19-inch standard rack slot, supports hot swapping.

Dimensions: 203mm (height) × 330mm (depth) × 51mm (width).

Weight: Approximately 1.5kg.

Protection level: IP20 (installed in control cabinet).

Certification and compliance

Industry standards: Compliant with API 670 Rotating Machinery Monitoring and Protection Standards.

Electromagnetic compatibility: CE certification, compliant with EN 61000-6-2/4.

Safety and environmental protection: UL certification, RoHS compliance.

V. Structural Design

Module: Integrated compact frame structure, divided into front panel, internal circuitry, and rear terminal block. The front panel integrates dual analog meters, LCD digital display window, multiple groups of LED status indicators and local operation keys. It enables real-time viewing of A/B channel differential expansion values, probe status and alarm information, parameter configuration, and intuitive and convenient operation. The internal circuitry includes dual-channel probe signal conditioning unit, differential expansion calculation circuit, dual-channel independent alarm comparison circuit, relay drive circuit and self-diagnosis unit. The functional zones are clearly defined, the layout is compact, the metal shielding layer suppresses internal interference, ensuring long-term stable operation. The rear terminal block is clearly zoned and marked, covering dual probe input, dual-channel relay output, dual-channel buffer output, power and communication interfaces. The wiring is convenient, facilitating on-site construction and maintenance. The module and the rack use gold-plated connectors, with reliable contact, wear-resistant, and oxidation-resistant properties. The electrical connection is stable during hot swapping, and module replacement does not require downtime, reducing the impact of maintenance on production.

VI. System Compatibility

Hardware compatibility

Rack and power supply: Compatible with 3300 series 19-inch rack, power module, system monitoring module, and can be installed with vibration, shaft displacement, shell expansion, speed, etc. modules.

Sensors: Fully compatible with original 3300 series 11mm eddy current probes, interchangeable with the same specification.

Output connection: Relay contacts connected to audible and visual alarms, DCS/PLC, interlock circuits; Buffer output connected to recorders, oscilloscopes, external instruments.

Software compatibility

Configuration software: Compatible with 3300 series dedicated configuration software, supports remote parameter configuration, alarm logic editing, firmware upgrade.

Monitoring software: Connected to System 1 platform, realizes real-time data, trend analysis, fault recording, report generation and remote access.

VII. Typical Application Scenarios

Power industry: Rotor-shaft differential expansion monitoring for steam turbine rotors in thermal power / nuclear power plants, dual-channel redundant measurement to enhance reliability, tracking thermal expansion differences during start-up, load increase processes, dual-level alarm linkage and interlock to prevent dynamic friction, axial rubbing, ensuring safe start-up and stable operation of the unit.

Petrochemical industry: Rotor differential expansion monitoring for large-scale process turbines, centrifugal compressors, in high-temperature conditions, tracking thermal deformation, simultaneous monitoring of two measurement points, differential expansion over-limit alarm, preventing equipment deformation, misalignment failure-induced production interruptions.

Metallurgical industry: High-pressure turbine exhaust, large transmission turbine rotor differential expansion monitoring, dual-channel independent monitoring of different positions' differential expansion, monitoring of thermal expansion trends during start-up and load increase processes, early warning and linkage alarms, reducing equipment failure shutdown risks.

VIII. Installation and Maintenance Specifications

Installation requirements

Rack installation: Push in smoothly into the vacant slot of the 3300 rack, ensure that the rear connectors are fully engaged, tighten the panel screws to prevent loosening.

Probe wiring: Connect the dual probe cables according to A/B channel markings, single-ended ground the shielding layer to suppress electromagnetic interference.

Alarm wiring: Distinguish ALERT and DANGER contacts, connect to the alarm/interlock circuits to confirm the logic is correct. Power-up Configuration: Confirm - 24V DC power supply is normal. Set the range, alarm threshold, delay, and probe calibration parameters through the panel or software and save them.

Probe Installation: Fix the probe in the housing, align it with the axial end face of the rotor, strictly control the installation gap (4mm linear zone), secure it firmly, protect the cables well to avoid vibration wear.

Daily Maintenance

Inspection: Observe the panel display and LED status, confirm that the differential expansion value is normal and there are no fault alarms; check that the terminals are not loose, oxidized, or overheated.

Calibration: Calibrate the accuracy annually using a standard displacement generator, in accordance with API 670 standards; regularly check the probe linearity.

Cleaning: Regularly clean the dust on the module and the rack to ensure ventilation and heat dissipation, and avoid dust-induced short circuits and poor heat dissipation.

Replacement of Spare Parts: When the module, probe, or cable is damaged, it is necessary to select the original Bentley model with the same specification to ensure compatibility and measurement accuracy.

IX. Usage Precautions

This model is non-explosion-proof. Do not install or use it in flammable and explosive hazardous areas; for explosion-proof conditions, select the model with an intrinsic safety safety barrier.

It must be paired with the original Bentley 3300 series 11mm eddy current probe. Different specifications of probes cannot be mixed; otherwise, the signals will not match and the measurement will fail.

The installation gap and coaxiality of the probe must be strictly set according to the manual. Installation deviations will cause signal distortion and increase measurement errors.

Do not disassemble the module, modify the internal circuitry, or modify the probe calibration parameters privately. Illegal operations will cause equipment damage and invalid warranty.

Before wiring, maintenance, or replacing the module, cut off the power supply of the rack to prevent short circuits and electric shock accidents.

Alarm threshold and delay should be set in combination with the unit process. Improper parameters will lead to frequent false alarms or warning failure.

Keep the installation location away from frequency converters, transformers, high-voltage cabinets, etc., which are strong electromagnetic interference sources, to reduce signal interference and ensure stable monitoring.