Bentley 3300/35-02-01-01-02 Six-Channel RTD Temperature Monitoring Module Detailed Product Description

I. Product Overview

The Bentley 3300/35-02-01-01-02 is a six-channel RTD (platinum resistance) temperature monitoring module of the 3300 series TSI (turbo-generator monitoring instrument) system developed by Baker Hughes (formerly GE Bentley Nevada). It is specifically designed for high-precision temperature monitoring and over-limit protection of large-scale rotating machinery (such as steam turbines, gas turbines, generators, compressors, etc.) in the power generation, nuclear power, petrochemical, and metallurgical industries. 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 Pt100 RTD, with a measurement range of 0–600°C, providing six independent temperature measurements, dual-level alarm, non-sealed SPDT relay output, 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 low-temperature conditions.

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

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 the measurement range of **0–600°C**, suitable for the high-temperature section of Pt100 RTD, covering bearing, winding, lubricating oil, sealing cavity, etc. in low-temperature measurement points.

01: Sensor type code, suitable for Pt100 RTD (platinum resistance), an industrial general-purpose low-temperature temperature measurement configuration.

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

02: Output configuration code, with 4-20mA analog output, capable of connecting to DCS/PLC systems, achieving remote transmission of temperature signals.

III. Core Functions

1. Six-channel high-precision Pt100 RTD temperature measurement

Independent 6 RTD inputs, each adapted to Pt100 platinum resistance (three-wire system, IEC 751 standard), measurement range 0–600°C, covering normal operation and abnormal overheating intervals of rotating machinery bearings, windings, lubricating oil, sealing cavities, etc. High-precision constant current source excitation and signal conditioning technology is adopted, measurement accuracy ≤ ±0.1°C (25°C reference point), resolution up to 0.1°C, capable of accurately capturing small temperature changes in the low-temperature range. Real-time monitoring of RTD circuit status, early warning of broken wires, short circuits, incorrect wiring, cable damage, etc., suitable for complex industrial environments with strong electromagnetic interference and severe vibration.

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

Each channel independently configured with **alert (ALERT) and danger (DANGER)** two-level alarm thresholds, configurable through panel local configuration or remote setting, suitable for different low-temperature protection requirements in different equipment. Equipped with 2 non-sealed SPDT 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 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 low-temperature abnormalities.

3. 4-20mA analog output, supporting signal remote transmission Each channel corresponds to a 4-20mA standard analog output. It can remotely transmit 6 real-time temperature signals to DCS, PLC or other secondary instruments, enabling centralized monitoring and data recording. The analog output accuracy is ≤ ±0.1% FS, with a load capacity of 0–500Ω. It meets industrial standard signal transmission requirements, without the need for additional signal conversion modules, simplifying system integration and adapting to scenarios requiring local monitoring and remote signal connection.

4. Local 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 6 temperature measurement values, RTD circuit resistance, alarm thresholds, analog output status and fault codes in real time. The OK, ALERT, DANGER, and BYPASS four sets of LEDs correspond to normal operation, warning alarm, dangerous alarm, and module bypass status respectively. The operating status is clearly visible. It supports on-site button-based configuration, allowing for range calibration, RTD type matching, circuit resistance calibration, alarm threshold configuration, delay parameter adjustment, analog output calibration, and loop diagnosis settings without the need for an upper computer, making the debugging efficient and convenient, and reducing the difficulty of on-site maintenance.

5. Comprehensive Self-Diagnosis and Fault Identification

The module continuously monitors its own hardware, RTD circuit, analog output circuit, power supply status and signal integrity without interruption. It can accurately identify RTD open circuit / short circuit, wiring errors, analog output overload, power fluctuations, module circuit faults, etc. The panel LEDs clearly indicate the fault type, and in combination with the on-site display of fault codes, it facilitates rapid troubleshooting and maintenance, reducing the risk of unplanned shutdown due to low-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, is 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 Bentley System 1 equipment status monitoring platform to achieve remote configuration, real-time data transmission, historical trend query, fault warning analysis, etc., integrating into the enterprise equipment management system. It supports interfacing with third-party systems such as DCS and PLC through 4-20mA analog signals or bus protocols, 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 Pt100 RTD)

Sensor Type: Pt100 platinum resistance (three-wire system, IEC 751 standard)

Measurement Range: 0–600℃

Measurement Accuracy: ≤ ±0.1℃ (25℃ reference point, typical value)

Resolution: 0.1℃

Excitation Current: 1mA (constant current source, independent for each channel)

Response Time: ≤ 3 seconds (reaching 90% stable reading)

Input Impedance: ≥ 10MΩ (each channel)

Electrical Parameters

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

Power Consumption: Typical 3.2W, maximum ≤ 5.5W

Relay Output: 2 SPDT (ALERT+DANGER), non-sealed type, 250V AC/5A, 30V DC/5A

Analog Output: 6 4-20mA, accuracy ≤ ±0.1% FS, load 0–500Ω

Isolation Strength: Input / Power Supply ≥ 2500V AC; Input / Analog Output ≥ 1500V AC

Sensor Power Supply: Module internal constant current source excitation, no external power supply required

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 standard, anti-vibration and anti-shock

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

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

Weight: Approximately 1.4kg

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

Certifications and compliance

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

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 / generator): Multi-point monitoring of turbine bearing temperature, generator winding temperature, lubricating oil temperature, sealing oil temperature, preventing overheating-induced bearing burnout, insulation aging, and equipment damage; full-stage low-temperature protection during startup acceleration, normal operation, and shutdown rotation, triggering alarms or interlock shutdown for over-temperature, while uploading temperature data via 4-20mA signal to DCS system for centralized monitoring to ensure safe and stable operation of the unit.

Petrochemical industry (large compressors / pump sets / heating furnaces): Synchronous monitoring of compressor bearing temperature, pump set winding temperature, heating furnace medium temperature, equipment shell temperature, suitable for medium-low temperature and high-vibration industrial environments, preventing equipment failure and production interruption due to overheating; analog output signal connects to the factory DCS system to achieve real-time temperature monitoring and historical traceability, ensuring continuous industrial production.

Metallurgical industry (large motors / fans / rolling mills): Batch monitoring of motor winding temperature, fan bearing temperature, rolling mill lubricating oil temperature, key equipment temperatures, dual-level relay alarm linkage for equipment operation interlock, timely warning of overheating faults; 4-20mA analog output compatible with metallurgical industry automation control systems, achieving centralized management of temperature data, reducing unplanned downtime risks, and ensuring 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: Pt100 RTD uses three-wire connection (red, white, black), equipped with dedicated RTD shielded cable, 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 wiring: Distinguish ALERT and DANGER relay contacts (SPDT with common terminal, normally open, normally closed), connect to the alarm/interlock circuit, confirm that the wiring is firm and there is no short-circuit hazard, to ensure reliable output of alarm signals.

Analog output wiring: 4-20mA output terminal connects to the analog input terminal of DCS/PLC, pay attention to the positive and negative polarity, use shielded cables, single-ended grounding of the shielding layer, to reduce signal interference.

Sensor installation: RTD probe is tightly attached to the surface of the measured equipment, fixed with thermal conductive silicone and a high-temperature clamp, ensuring 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-check: After the module is powered on, it automatically performs self-check, the OK light is constantly on indicating normal hardware, when the fault light is on, check the wiring, sensors, or hardware issues. Sensor Calibration: Enter the calibration mode by pressing the panel buttons, select the Pt100 RTD type, calibrate the three-wire circuit resistance, and ensure the temperature measurement accuracy.

Alarm Settings: According to the equipment operation standards, set the warning threshold (such as 120℃) and the dangerous threshold (such as 150℃), adjust the alarm delay (such as 2 seconds), and save the parameters.

Simulation Output Calibration: Enter the simulation output calibration mode, calibrate the 4mA (corresponding to 0℃) and 20mA (corresponding to 600℃) output accuracy, and ensure the signal transmission accuracy.

Signal Verification: During the equipment operation, observe whether the 6-channel temperature values on the panel are stable, without jumps or drifts; check if there are no fault prompts in the RTD circuit, confirm that the alarm function and the simulation output signal are normal, and then put it into operation.

Maintenance and Fault Troubleshooting

Daily Maintenance

Regular Inspection: Daily observe the panel temperature values, circuit status, and LED status, confirm no alarms or fault prompts; check if the module terminal connections are not loose or oxidized, if the rack ventilation and heat dissipation are good, and if the simulation output signal is stable.

Annual Calibration: Use the standard Pt100 RTD to calibrate the temperature measurement accuracy every year, verify the relay alarm action value and delay accuracy, calibrate the 4-20mA simulation output accuracy, and ensure the monitoring, alarm, and signal transmission functions are reliable.

Cleaning and Protection: Regularly clean the module surface dust 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 Fault): Check if the backplane power supply is normal (-24V DC), reinsert the module, and if still abnormal, replace the module.

Abnormal Temperature Display (Jumps / Drifts): Check if the Pt100 RTD wiring is loose, wrongly connected, or broken, and if the cables are damaged. Reconnect the wiring or replace the sensor; check if the environmental temperature is beyond the working range or if there is strong electromagnetic interference.

No Temperature Display: Check if the RTD is damaged, if the three-wire circuit wiring is incorrect, if the cables are broken, and check and replace the faulty components.

Alarm Mis-triggered: Re-calibrate the alarm threshold and delay parameters, check if the RTD circuit resistance is abnormal, optimize the sensor installation and wiring shielding measures.

Simulation Output Abnormal (No Signal / Signal Drift): Check if the simulation output wiring is loose, if the positive and negative poles are connected reversely, if the simulation output is disconnected, calibrate the simulation output accuracy, and check if the load is within the range.

Eight. Usage Precautions

This model is not designed for explosion-proof use; it is strictly prohibited to install and use it in flammable and explosive hazardous areas.

It must be equipped with **Pt100 platinum resistance (three-wire system, IEC 751 standard)** temperature sensor and dedicated RTD shielding cable; it is not allowed to mix with thermocouples (such as K type) or two-wire / four-wire RTD; otherwise, it will cause measurement errors or equipment damage.

It is only applicable for temperature monitoring within 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.