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

I. Product Overview

The Bentley 3300/35-01-01-02-00-00 is a six-channel RTD temperature monitoring module of the 3300 series TSI (Turbo Generator Instrumentation) system developed by 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 for high-precision temperature monitoring in the low-temperature sections. 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 **-40℃ to +125℃**, providing six independent temperature measurements, dual-level sealed SPDT relay outputs, no analog output, and complete self-diagnosis functions, in accordance with API 670 standards. It is the core equipment for monitoring the low-temperature state of rotating machinery and providing high-reliability alarm protection.

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

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.

01: Range code, corresponding to **-40℃ to +125℃** measurement range, suitable for Pt100 RTD in the low-temperature section, covering bearing, winding, lubricating oil, environmental cavity, etc. low-temperature measurement points.

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

02: Relay configuration code, equipped with dual SPDT sealed alarm relays, suitable for harsh industrial environments such as dampness and dust for alarm and interlock circuits.

00: Output configuration code, no analog output, only retaining relay alarm and system bus communication functions.

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

III. Core Functions

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

Independent 6 RTD inputs, each adapted to Pt100 platinum resistance (three-wire system, IEC 751 standard), measurement range **-40℃ to +125℃**, covering normal operation and abnormal overheating intervals of rotating machinery. Using high-precision constant current source excitation and signal conditioning technology, measurement accuracy ≤ ±0.1℃ (25℃ reference point), resolution up to 0.1℃, capable of accurately capturing minute temperature changes in the low-temperature section. Real-time monitoring of RTD circuit status, early warning of wire breakage, short circuit, wiring error, cable damage, etc., suitable for complex industrial environments with strong electromagnetic interference, severe vibration, and damp dust.

2. Dual-level sealed SPDT relay output, high-reliability alarm in harsh environments

Each channel independently configured with **alert (ALERT) and danger (DANGER)** two-level alarm thresholds, configurable via panel local configuration or remote setting, suitable for different low-temperature protection requirements of different equipment. Equipped with 2 sealed SPDT relays, contact specifications 250V AC/5A, 30V DC/5A, with moisture-proof, dust-proof, and vibration-resistant characteristics, can directly drive audible and visual alarms, DCS/PLC interlock circuits or shutdown protection devices, suitable for harsh industrial environments with dampness and dust. Alarm delay adjustable from 0 to 10 seconds, filtering instantaneous temperature fluctuations, avoiding false alarms; The relay status is linked with the module operation status. When a fault occurs, it automatically triggers an alarm to ensure timely response to low-temperature abnormalities.

3. No analog output. Focuses on alarm protection in harsh environments.

This model does not have an independent analog output function. The core focuses on low-temperature monitoring + dual-stage sealed relay high-reliability alarm protection. It adopts a sealed relay design to enhance the operational stability in humid and dusty environments, suitable for harsh industrial scenarios with extremely high requirements for alarm reliability. Through the 3300 series system bus, it can upload 6 real-time temperature data, alarm status, and fault information to the BTL System 1 platform, enabling remote monitoring and data management, meeting the needs of low-temperature monitoring and protection.

4. Local display and convenient configuration

The front panel is equipped with an LCD digital display window and multiple status LED indicators. It can display the real-time temperature measurement values of 6 channels, RTD circuit resistance, alarm thresholds, and fault codes. The OK, ALERT, DANGER, and BYPASS four groups of LEDs correspond to normal operation, warning alarm, dangerous alarm, and module bypass status, making the operational status visible at a glance. It supports on-site button-based configuration, allowing for range calibration, RTD type matching, circuit resistance calibration, alarm threshold configuration, delay parameter adjustment, 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

It continuously monitors the module's own hardware, RTD circuit, power supply status, and signal integrity 24 hours a day. It can accurately identify RTD open circuit / short circuit, wiring errors, power fluctuations, module circuit faults, etc. The panel LEDs clearly indicate the fault type, and in combination with the local display of fault codes, it facilitates quick 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, high vibration, and humid dusty conditions. It is compatible with the 3300 series system bus (type A), and can be connected to the BTL 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 bus protocol, meeting factory automation integration requirements, and ensuring stable transmission of temperature monitoring data.

Four. 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: -40℃ to +125℃

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

Resolution: 0.1℃

Excitation current: 1mA (constant current source, independent per channel)

Response time: ≤ 3 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 3.0W, maximum ≤ 5.0W

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

Analog output: None

Isolation strength: Input / power supply ≥ 2500V 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, resistant to vibration and shock

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

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

Weight: Approximately 1.4kg

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 low-temperature bearing temperatures of turbines, cold-end winding temperatures of generators, low-temperature lubricating oil temperatures, and ambient temperatures of sealing cavities, to prevent equipment damage caused by low-temperature abnormalities or overheating; full-stage low-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 compressors / pump sets / outdoor equipment): Synchronous monitoring of low-temperature bearing temperatures of compressors, ambient temperatures of pump sets, shell temperatures of outdoor equipment, and low-temperature medium temperatures, suitable for humid, dusty, and outdoor harsh industrial environments, to prevent low-temperature faults or overheating from causing equipment failures and production interruptions, ensuring continuous industrial production.

Metallurgical industry (large motors / fans / cooling equipment): Batch monitoring of low-temperature winding temperatures of motors, bearing temperatures of fans, medium temperatures of cooling equipment, and key component low-temperature measurement points, dual-level sealed relay alarm linkage for equipment operation interlocks, timely warning of low-temperature abnormal or 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 in 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 contact failure; 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 shield 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; in harsh environments, handle the wiring terminals for moisture and dust protection.

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, keep away from strong electromagnetic radiation sources; in humid environments, provide waterproof protection for the probe.

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 Pt100 RTD type, calibrate the three-wire circuit resistance to ensure temperature measurement accuracy.

Alarm settings: According to the equipment operation standards, set the warning threshold (e.g. 80℃) and danger threshold (e.g. 100℃), adjust the alarm delay (e.g. 2 seconds), save parameters. Signal verification: During the operation of the equipment, observe whether the 6-channel temperature values on the panel are stable, without fluctuations or drift; check that there are no fault indications in the RTD circuit and confirm that the alarm function is normal before putting it into operation.

Maintenance and Fault Troubleshooting

Daily Maintenance

Regular Inspection: Daily observation of the temperature values on the panel, the status of the circuit, and the LED status to confirm no alarms or fault indications; check that the terminal connections of the module are not loose, oxidized, or damp, and that the ventilation and heat dissipation of the rack are good.

Annual Calibration: Use standard RTD to calibrate the temperature measurement accuracy every year, verify the accuracy of the relay alarm action value and delay, and ensure the reliability of the monitoring and protection functions.

Cleaning and Protection: Regularly clean the dust on the surface of the module with a dry soft cloth to avoid dust accumulation affecting heat dissipation; strictly prohibit liquids, metal debris from entering the module interior to prevent short-circuit faults; regularly check the sealing performance in harsh environments.

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 (fluctuation / drift): Check if the Pt100 RTD wiring is loose, wrongly connected, broken, or damp, and if the cables are 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 RTD is damaged, if the three-wire connection of the RTD is incorrect, if the cables are broken, and check and replace the faulty components; 

Alarm mis-trigger: Re-calibrate the alarm threshold and delay parameters, check if the resistance of the RTD circuit is abnormal, optimize the installation and wiring shielding, and moisture-proof measures of the sensor.

Safety Precautions for Use

This model is not designed for explosion-proof; 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 lead to measurement errors or equipment damage.

It is only applicable for temperature monitoring in the range of -40℃ to +125℃. For over-temperature scenarios, select the corresponding range module.

It is strictly prohibited to disassemble the module, modify the internal circuitry, or replace non-original accessories. 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.