Bentley 3300/35-02-02-01-01-00 Six-channel K-type Thermocouple Temperature Monitoring Module Detailed Product Description

I. Product Overview

The Bentley 3300/35-02-02-01-01-00 is a six-channel K-type thermocouple temperature monitoring module within the 3300 series TSI (Turbo Generator Instrumentation) system of Baker Hughes (formerly GE Bentley Nevada), specifically designed for high-precision temperature monitoring and over-limit protection of high-temperature measurement points in large rotating machinery (such as steam turbines, gas turbines, generators, compressors, etc.) in industries such as thermal power, nuclear power, petrochemicals, and metallurgy. The module adopts a 19-inch standard rack structure, supports hot-swapping, and can be mixed with other monitoring modules of the 3300 series to share the backplane - 24V DC power supply and system bus; it is compatible with K-type thermocouples, with a measurement range of 0–1200°C, providing six independent temperature measurements, dual-level alarms, single-channel common isolation 4–20mA analog output, and complete self-diagnosis functions, in accordance with API 670 standards. It is the core equipment for monitoring and fault protection of rotating machinery in high-temperature conditions.

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.

02: Range code, corresponding to **0–1200°C** measurement range, suitable for K-type thermocouples in the high-temperature section, covering high-temperature measurement points such as steam turbine casings, exhaust, gas turbine combustion chambers, etc.

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

01: Relay configuration code, equipped with dual-channel SPST non-sealed alarm relays, suitable for conventional industrial environment alarms and interlock circuits.

01: Output configuration code, provides 1 public isolation 4–20mA analog output, configurable for specific channel output or round-robin output.

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

III. Core Functions

1. Six-channel high-precision K-type thermocouple temperature measurement

Independent 6 channels of thermocouple input, each channel compatible with K-type thermocouples (nickel-chromium - nickel-silicon), measurement range 0–1200°C, covering normal operation and abnormal overheating intervals of rotating machinery. Utilizing high-precision built-in automatic cold junction compensation circuit (compensation range 0–50°C) 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 in the high-temperature section. Real-time monitoring of thermocouple circuit status, early warning of breakage, short circuit, incorrect wiring, mismatch or damage of compensation wires, etc., suitable for complex industrial environments with strong electromagnetic interference and severe vibration.

2. Dual-level alarm and non-sealed relay output

Each channel independently configured **alert (ALERT), danger (DANGER)** two-level alarm thresholds, configurable via panel local configuration or remote setting, suitable for different equipment's high-temperature protection requirements. Equipped with 2 non-sealed SPST relays, contact specifications 250V AC/5A, 30V DC/5A, capable of directly driving audible and visual alarms, DCS/PLC interlock circuits or shutdown protection devices. Alarm delay adjustable from 0–10 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 anomalies.

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, thermocouple type matching, cold junction compensation on/off, alarm threshold configuration, delay parameter adjustment, and loop diagnosis settings. The debugging 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, with a fixed output of 4–20mA current signal. The output signal is electrically isolated from the power supply, input signal, and has an electrical isolation strength of ≥2500V AC, effectively suppressing industrial site electromagnetic interference and ground circulating current influence. The output content can be configured as the real-time temperature value of a specified single channel or 6-channel rotation output. It can be connected to recorders, DCS systems or data acquisition platforms, used for 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, cold junction compensation status, power supply status and signal integrity 24 hours a day. It can accurately identify issues such as thermocouple breakage / short circuit, compensation wire errors, cold junction compensation abnormalities, power fluctuations, module circuit faults. It distinguishes between real temperature anomalies and sensor / circuit faults. The panel LEDs clearly indicate the fault type, and in combination with on-site display of fault codes, it facilitates 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, and 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 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: 0–1200℃

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

Resolution: 0.1℃

Cold Junction Compensation: Built-in automatic cold junction compensation, compensation range 0–50℃

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

Input Impedance: ≥10MΩ (per channel)

Electrical Parameters

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

Power Consumption: Typical 2.8W, maximum ≤4.5W

Relay Output: 2 SPST (ALERT+DANGER), non-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℃ to +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 1.3kg

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 turbine cylinder temperature, exhaust temperature, gas turbine combustion chamber temperature, exhaust gas temperature, prevent overheating-induced material aging, component deformation, equipment damage; full-stage high-temperature protection during startup acceleration, normal operation, shutdown rotation, triggering alarms or interlock shutdown when overheating occurs, ensuring safe and stable operation of the unit.

Petrochemical industry (large cracking turbines / process heating furnaces): Synchronous monitoring of turbine high-temperature bearing temperature, sealing chamber temperature, heating furnace outlet temperature, reaction medium temperature, suitable for high-temperature, high-pressure, and highly corrosive industrial environments, prevent equipment burnout, medium cracking, and safety accidents, ensuring continuous industrial production.

Metallurgical industry (large heating furnaces / sintering machines / high-temperature fans): Batch monitoring of furnace interior temperature, flue gas temperature, equipment high-temperature shell temperature, winding temperature, dual-level alarm linkage with equipment operation interlock, timely warning of overheating faults, reduce unplanned shutdown risks, ensure stable and efficient operation of the metallurgical process.

VI. Installation and commissioning specifications

Installation requirements

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

Sensor wiring: K-type thermocouple uses positive and negative polarity separation wiring (positive nickel chromium, negative nickel silicon), equipped with dedicated K-type compensation cables, select high-temperature-resistant shielded 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 ALERT and DANGER relay contacts, connect to the alarm/interlock circuit; analog output terminals are connected according to the requirements of DCS/recorders interfaces, confirm the correct signal polarity to ensure stable transmission of 4–20mA signals.

Sensor installation: Thermocouple probe is tightly attached to the high-temperature surface of the measured equipment, fixed using a high-temperature clamp to ensure accurate temperature measurement; fix the probe cable firmly to avoid vibration wear or cable breakage, 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 calibration mode through the panel buttons, select K-type thermocouple type, enable automatic cold junction compensation, calibrate the loop resistance parameters to ensure temperature measurement accuracy.

Alarm settings: According to the equipment operation standards, set the warning threshold (e.g. 800℃) and danger threshold (e.g. 1000℃), adjust the alarm delay (e.g. 2 seconds), save parameters.

Signal verification: During equipment operation, observe whether the 6-channel temperature values on the panel are stable, without jumps, drifts; check that the thermocouple circuit has no fault indication, confirm that the signal is correct before putting it into operation.

VII. Maintenance and fault troubleshooting

Daily maintenance Regular inspection: Daily observation of panel temperature values, circuit status and LED status, confirming no alarms or fault indications; checking that module terminal connections are not loose or oxidized, and that the rack ventilation and cooling are in good condition.

Annual calibration: Using standard thermocouples to calibrate temperature measurement accuracy, verifying the accuracy of relay alarm action values and delay, ensuring reliable monitoring and protection functions.

Cleaning and protection: Regularly cleaning module surface dust with a dry soft cloth to avoid dust accumulation affecting heat dissipation; strictly prohibiting 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 (jumps / drifts): Check if the K-type thermocouple wiring is loose, miswired, or broken, if the compensation wires are matched, damaged, rewire or replace the sensor; check if the environmental temperature is beyond the working range and if there is strong electromagnetic interference.

No temperature display: Check if the thermocouple is damaged, if the positive and negative poles are connected reversely, if the compensation wires are open-circuited, and troubleshoot and replace faulty components.

Alarm mis-triggering: Re-calibrate the alarm threshold and delay parameters, check if the cold junction compensation is abnormal, optimize 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 sensor and dedicated K-type compensation wires. Mixing with other types of thermocouples (such as S-type, B-type) or RTD is not allowed, otherwise it will cause measurement errors or equipment damage.

It is only applicable for temperature monitoring within 0–1200℃. 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, the main power supply of the rack must be cut off 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.