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

I. Product Overview

The Bentley 3300/35-03-02-02-00-00 is a six-channel thermocouple temperature monitoring module within the 3300 series TSI (Turbo Generator Instrumentation) system of Baker Hughes (formerly GE Bentley Nevada), 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 for high-temperature measurement point temperature monitoring and protection. 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 (nickel-chromium - nickel-silicon), covering a high-temperature measurement range of 0–600°C, providing six independent temperature measurement channels, dual-level alarm, isolated analog output, and comprehensive self-diagnosis functions, in accordance with API 670 standards. It is the core equipment for the state monitoring and fault protection of high-temperature parts 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 the **0–600°C** measurement range, suitable for the high-temperature section of K-type thermocouples, covering high-temperature measurement points such as bearings, exhaust, stator, etc.

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

02: Relay and output configuration code, equipped with two SPST sealed alarm relays + 6 4–20mA isolated analog outputs.

00: Certification level code, representing general industrial-grade certification, suitable for conventional 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 key high-temperature parts of rotating machinery; using 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 minor 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, can directly drive 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 status LED indicators, capable of real-time display of 6 temperature measurement values, thermocouple circuit resistance, alarm thresholds, and fault codes; OK, ALERT, DANGER, BYPASS - four groups of LED lights, respectively corresponding to normal operation, warning alarm, danger alarm, and module bypass status. The operating status can be clearly seen; it supports on-site button-based configuration, allowing for range calibration, cold end compensation settings, alarm threshold configuration, delay parameter adjustment, sensor type matching, etc., without the need for an upper computer. This enables efficient and convenient debugging, reducing the difficulty of on-site maintenance.

4. Six-channel isolated analog signal output

Provides 6 independent isolated buffer analog outputs (1 channel per output), with a fixed output of 4–20mA current signal. The output signal is electrically isolated from the power supply and input signal with an electrical isolation strength of ≥2500V AC, effectively suppressing electromagnetic interference and ground loop current in industrial environments. 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 tracing 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

24-hour continuous monitoring of the module's own hardware, thermocouple circuit, power supply status and signal integrity. It can accurately identify thermocouple breakage / short circuit, polarity reversal, cold end compensation abnormalities, power fluctuations, module circuit faults, etc.; distinguishes between real high-temperature anomalies and sensor / circuit faults. The panel LED clearly indicates the fault type, and the on-site display of fault codes facilitates rapid troubleshooting and maintenance, reducing the risk of unplanned shutdown due to high-temperature faults.

6. System integration and strong anti-interference capability

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; compatible with 3300 series system bus (Type A), can be connected to the Bentek System 1 equipment status monitoring platform, enabling remote configuration, real-time data transmission, historical trend query, fault warning analysis and other functions, integrated into the enterprise equipment management system; supports seamless connection with DCS, PLC and other third-party systems, meeting factory automation integration requirements, ensuring stable transmission of high-temperature monitoring data.

Four. Detailed technical parameters

Measurement parameters

Monitoring channels: 6 independent temperature measurement (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

Working 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: 6 isolated 4–20mA current signals, load resistance ≤500Ω

Isolation strength: ≥2500V AC between input/output/power supply

Sensor power supply: no external power supply, 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: meets IEC 60068-2 standard, anti-vibration, anti-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)

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 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 temperatures; full-stage high-temperature protection during startup acceleration, normal operation, and shutdown rotation, triggering alarms or interlocks 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, 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 temperatures, ensuring continuous industrial production.

Metallurgical industry (large-scale 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 interlocks, 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

Frame installation: Push smoothly into the vacant slot of the 3300 series frame, 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: Connect K-type thermocouples according to the module terminal markings for positive and negative polarity, 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, to prevent breakage or signal attenuation.

Alarm and Output Wiring: Distinguish ALERT and DANGER relay contacts, connect to the alarm/interlock circuits; connect 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； fix the probe cable firmly to avoid vibration wear or cable breakage， and keep away from strong electromagnetic radiation sources.

Commissioning Steps

Power-on Self-Test： The module powers on and automatically performs self-checks. The OK light is always 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 junction compensation parameters to ensure high-temperature measurement accuracy.

Alarm Settings： Based on the equipment operation standards， set warning thresholds (e.g.， 450°C) and danger thresholds (e.g.， 550°C)， adjust 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 the signal is correct， and then put 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； check that the module terminal connections are not loose or oxidized， and the frame ventilation and heat dissipation are good.

Annual Calibration： Use a standard temperature source to calibrate the high-temperature measurement accuracy annually， verify the alarm action values and delay accuracy of the relays， ensure reliable monitoring and protection functions. Cleaning and Protection: Regularly clean the dust on the surface of the module with a dry soft cloth to prevent dust accumulation from 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 broken, 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.

Alarm triggered incorrectly: 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 Precautions

This model is of non-explosion-proof design; it is strictly prohibited to install and use it in flammable and explosive hazardous areas.

It must be equipped with **K-type thermocouple (nickel-chromium - nickel-silicon)** temperature sensor, and other types of sensors (such as Pt100, R-type thermocouple) must not be mixed; 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 privately, modify the internal circuitry or replace non-original accessories; improper operation will result in the invalidation of equipment warranty and may also cause safety hazards.

Before connecting or inspecting the module, the main power supply of the frame 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 frame, store it in a dry and cool environment to avoid moisture and dust affecting performance.