Bentley 3300/35-03-02-01-00-00 Six-Channel Thermocouple Temperature Monitoring Module Detailed Product Description

I. Product Overview

The Bentley 3300/35-03-02-01-00-00 is a six-channel thermocouple temperature monitoring module within the 3300 series TSI (Turbo Generator Instrumentation) system of Baker Hughes (formerly GE Bentley Nevada). It is specifically designed for large-scale rotating machinery (such as steam turbines, gas turbines, generators, compressors, etc.) in the power generation, nuclear power, petrochemical, and metallurgical industries, providing high-precision online temperature monitoring and over-limit protection for critical high-temperature areas. The module adopts a 19-inch standard rack structure, supports hot-swapping, and can be mixed with other monitoring modules of the 3300 series, sharing the backplane - 24V DC power supply and system bus; it is compatible with K-type thermocouples (nickel-chromium - nickel-silicon), with a measurement range of 0–600°C, providing six independent temperature measurements, dual-level alarms, a single 4–20mA isolated analog output, and comprehensive self-diagnosis functions, in accordance with API 670 standards. It is the core equipment for the temperature status monitoring and fault protection of rotating machinery.

II. Model Coding Rules (3300/35-AA-BB-CC-DD-EE)

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

35: Function code, representing a six-channel temperature monitoring module, independently monitoring 6 temperature signals.

03: Range code, corresponding to **0–600°C** measurement range, suitable for the high-temperature section of K-type thermocouples, covering bearing, exhaust, stator, etc. high-temperature measurement points.

02: Sensor type code, suitable for K-type thermocouples (nickel-chromium - nickel-silicon), industrial standard high-temperature thermocouple configuration.

01: Relay and output configuration code, equipped with two SPST alarm relays + one common 4–20mA isolated analog output (different from the six-channel independent output of 02 code).

00: Certification level code, representing general industrial-level certification, suitable for routine industrial environments.

00: Safety barrier configuration code, representing no built-in safety barrier, only applicable to non-explosion-proof areas.

III. Core Functions

1. Six-channel high-precision thermocouple temperature measurement

Independent 6 channels of temperature input, each channel compatible with K-type thermocouples, measurement range 0–600°C, covering the normal operation and abnormal overheating intervals of rotating machinery. Adopting high-precision cold junction compensation circuit and signal conditioning technology, measurement accuracy ≤ ±0.5°C (25°C reference point), resolution up to 0.1°C, capable of accurately capturing minute temperature changes. Real-time monitoring of thermocouple circuit status, early warning of wire breakage, short circuit, polarity reversal, poor contact, etc., suitable for complex industrial environments with strong electromagnetic interference and severe vibration.

2. Dual-level alarm and sealed relay output

Each channel independently configured **ALERT (warning) and DANGER (dangerous)** two-level alarm thresholds, configurable through panel local configuration or remote setting, suitable for different equipment's high-temperature protection requirements. Equipped with 2 epoxy resin sealed SPST relays, contact specifications 250V AC/5A, 30V DC/5A, moisture-proof, dust-proof, vibration-resistant, directly driving audible and visual alarms, DCS/PLC interlock circuits or shutdown protection devices. Alarm delay adjustable from 0 to 10 seconds, filtering instantaneous temperature fluctuations, avoiding false alarms; relay status and module operation status are linked, automatically triggering alarms when faults occur, ensuring timely response to high-temperature abnormalities.

3. On-site display and convenient configuration The front panel is equipped with an LCD digital display window and multiple sets of status LED indicators, which can display the real-time temperature measurement values of 6 channels, the resistance of the thermocouple circuit, the alarm threshold, and the fault code. There are four sets of LEDs: OK, ALERT, DANGER, and BYPASS, corresponding to normal operation, warning alarm, dangerous alarm, and module bypass status respectively. The operation status is clearly visible. It supports on-site configuration via buttons, without the need for an upper computer to complete range calibration, cold end compensation settings, alarm threshold configuration, delay parameter adjustment, sensor type matching, etc. The operation is efficient and convenient, reducing the difficulty of on-site maintenance.

4. Single-channel common isolation analog signal output

It provides 1 channel of common isolation buffered analog output (summarizing 6 temperature signals, configurable to specify channel output or round-robin output), with a fixed output of 4–20mA current signal. The output signal is electrically isolated from the power supply and input signals with a strength of ≥2500V AC, effectively suppressing industrial site electromagnetic interference and ground circulating current influence. The output content is the real-time temperature value, which can be connected to recorders, DCS systems or data acquisition platforms, used for high-temperature trend analysis, fault traceability and data archiving, supporting equipment status assessment and preventive maintenance, and meeting the data connection requirements of industrial automation systems.

5. Comprehensive self-diagnosis and fault identification

It continuously monitors the module's own hardware, thermocouple circuit, power supply status and signal integrity 24 hours a day. It can accurately identify issues such as thermocouple breakage / short circuit, polarity reversal, abnormal cold end compensation, power fluctuations, module circuit faults. It distinguishes between real high-temperature anomalies and sensor / circuit faults. The panel LEDs clearly indicate the fault type, and the fault code is displayed on-site to facilitate rapid troubleshooting and maintenance, reducing the risk of unplanned shutdown caused by high-temperature faults.

6. System integration and strong anti-interference capability

The metal shielding shell design, multiple electrical isolation between input, output and power supply circuits, suitable for industrial environments with strong electromagnetic interference and high vibration such as thermal power, nuclear power, petrochemicals. It is compatible with the 3300 series system bus (Type A), and can be connected to the Bently System 1 equipment status monitoring platform to achieve remote configuration, real-time data transmission, historical trend query, fault warning analysis and other functions, integrating into the enterprise equipment management system. It supports seamless integration with DCS, PLC and other third-party systems, meeting factory automation integration requirements, and ensuring stable transmission of high-temperature monitoring data.

IV. Detailed Technical Parameters

Measurement Parameters

Monitoring Channels: 6 independent temperature measurements (compatible with K-type thermocouples)

Sensor Type: K-type thermocouple (nickel-chromium - nickel-silicon)

Measurement Range: 0–600℃

Measurement Accuracy: ≤±0.5℃ (25℃ reference point, typical value)

Resolution: 0.1℃

Cold End Compensation: Built-in automatic cold end compensation, compensation range 0–50℃

Response Time: ≤5 seconds (reaching 90% stable reading)

Input Impedance: ≥1MΩ (per channel)

Electrical Parameters

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

Power Consumption: Typical 2.5W, maximum ≤4W

Relay Output: 2 SPST (ALERT+DANGER), epoxy resin sealed, 250V AC/5A, 30V DC/5A

Analog Output: 1 isolated 4–20mA current signal, load resistance ≤500Ω

Isolation Strength: Input / Output / Power Supply ≥2500V AC

Sensor Power Supply: No external power supply required, thermocouple self-generated signal input

Environmental and Mechanical Parameters

Operating Temperature: 0℃~+65℃ (standard industrial grade)

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

Vibration tolerance: Compliant with IEC 60068-2 standards, resistant to vibration and shock

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

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

Weight: Approximately 1.2kg

Protection level: IP20 (suitable for installation in control cabinets)

Certifications 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 certification: UL certification

Environmental compliance: RoHS Directive compliance

V, Typical application scenarios

Power industry (thermal power / nuclear power turbine / gas turbine): Multi-point monitoring of exhaust temperature, bearing high temperature, stator winding high temperature, combustion chamber temperature, preventing component deformation, insulation aging, and equipment burnout due to high temperature; full-stage high-temperature protection during startup acceleration, normal operation, and shutdown rotation, triggering alarms or interlock shutdown upon over-temperature, ensuring safe and stable operation of the unit.

Petrochemical industry (large-scale process compressors / cracking turbines): Synchronous monitoring of multiple bearing high temperatures, sealing chamber high temperatures, and medium outlet temperatures, suitable for high-temperature, high-pressure, and highly corrosive industrial environments, preventing shaft wear, seal failure, and medium leakage caused by high temperature, ensuring continuous industrial production.

Metallurgical industry (large transmission turbines / heating furnace supporting units): Batch monitoring of key bearings high temperatures, equipment shell high temperatures, cooling medium outlet temperatures, dual-level alarm linkage with equipment operation interlock, timely warning of high-temperature overheating faults, reducing unplanned shutdown risks, ensuring stable and efficient operation of the metallurgical process.

VI. Installation and commissioning specifications

Installation requirements

Rack installation: Push into the 3300 series rack slot smoothly, ensure that the rear connectors are fully engaged, tighten the panel fixing screws to avoid loosening and contact failure; reserve ventilation space at the installation location to avoid heat accumulation affecting module heat dissipation.

Sensor wiring: K-type thermocouple is wired according to the module terminal markings, positive and negative poles are connected, use high-temperature-resistant shielded compensation cables, single-ended grounding of the shielding layer (on the control cabinet side), to avoid circulating interference; during wiring, avoid bending or pulling the cables, prevent breakage or signal attenuation.

Alarm and output wiring: Distinguish between ALERT and DANGER relay contacts, connect to the alarm/interlock circuit; connect the analog output terminals according to the DCS/record仪 interface requirements， confirm the correct signal polarity to ensure stable transmission of 4–20mA signals.

Sensor installation： The thermocouple probe is tightly attached to the high-temperature surface of the measured equipment， fixed with high-temperature-resistant thermal adhesive to ensure accurate temperature measurement； the probe cable is firmly fixed to avoid vibration wear or cable breakage， and keep away from strong electromagnetic radiation sources.

Commissioning steps

Power-on self-check： The module powers on and automatically performs self-check， the OK light is constantly on indicating normal hardware， when the fault light is on， troubleshoot the wiring， sensors， or hardware issues.

Sensor calibration： Enter the calibration mode through the panel buttons， select K-type thermocouple type， calibrate the cold end compensation parameters to ensure high-temperature measurement accuracy.

Alarm settings： According to the equipment operation standards， set the warning threshold (e.g. 450°C) and danger threshold (e.g. 550°C)， adjust the alarm delay (e.g. 2 seconds)， save the parameters.

Signal verification： During equipment operation， observe whether the 6-channel temperature values on the panel are stable， without jumps， drifts； check that there are no fault indications in the thermocouple circuit， confirm the signal is correct， and then put it into operation. Check that the terminal connections of the module are not loose or oxidized, and that the ventilation and heat dissipation of the rack are good.

Annual calibration: Use a standard temperature source to calibrate the high-temperature measurement accuracy every year, verify the accuracy of the relay alarm action value and delay, and ensure the reliability of monitoring and protection functions.

Cleaning and protection: Regularly clean the dust on the module surface with a dry soft cloth to avoid dust accumulation affecting heat dissipation; strictly prohibit liquids and metal debris from entering the module interior to prevent short-circuit faults.

Common fault troubleshooting

OK light goes out (module failure): Check if the backplane power supply is normal (-24V DC), reinsert and re-execute the module, if still abnormal, replace the module.

Abnormal temperature display (jumping / drift): Check if the K-type thermocouple wiring is loose, reversed polarity, or disconnected, if the shielding compensation cable is damaged, rewire or replace the sensor; check if the environmental temperature exceeds the working range and if there is strong electromagnetic interference.

No temperature display: Check if the thermocouple is damaged, if the wiring is incorrect, if the module cold end compensation is abnormal, and troubleshoot and replace the faulty components.

False alarm triggering: Re-calibrate the alarm threshold and delay parameters, check if the temperature signal is interfered with, optimize the sensor installation and wiring shielding measures.

VIII. Usage Notes

This model is of non-explosion-proof design. Installation and use are strictly prohibited in flammable and explosive hazardous areas.

It must be equipped with **K-type thermocouple (nickel-chromium - nickel-silicon)** temperature sensors. Do not mix with other types of sensors (such as Pt100, R-type thermocouple), otherwise it will cause measurement errors or equipment damage.

It is only applicable for high-temperature monitoring of 0–600℃. For over-temperature scenarios, select the corresponding range module.

Do not disassemble the module, modify the internal circuitry, or replace non-original accessories without authorization. Illegal operations will result in the invalidation of equipment warranty and may cause safety hazards.

Before connecting or inspecting the module, cut off the main power supply of the rack to prevent short circuits and electric shock accidents; do not plug or unplug the module while it is powered on.

When the module is in a long-term shutdown state, it is recommended to remove the module from the rack, store it in a dry and cool environment to avoid moisture and dust affecting performance.