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

I. Product Overview

The Bentley 3300/35-02-01-02-00-00 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, dual-channel SPDT relay output, and complete self-diagnosis functions, in accordance with API 670 standards. It is the core equipment for monitoring and fault protection of low-temperature states in 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.

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. as 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-channel SPDT sealed alarm relays, suitable for high-reliability alarms and interlock circuits in industrial environments.

00: Output configuration code, without analog output, only retaining alarm relay 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 Temperature Measurement

Independent 6 RTD inputs, each adapted to Pt100 platinum resistance (three-wire system), measurement range 0–600°C, covering normal operation and abnormal overheating intervals of rotating machinery bearings, windings, lubricating oil, sealing cavities, etc. Utilizing high-precision constant current source excitation and signal conditioning technology, measurement accuracy ≤ ±0.1°C (25°C reference point), resolution 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 Sealed SPDT Relay Output

Each channel independently configured **ALERT (warning) 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 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. 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. 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, RTD circuit resistance, alarm thresholds, and fault codes. 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. This model supports on-site configuration via buttons, 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. The operation is efficient and convenient, reducing the difficulty of on-site maintenance.

4. No analog output, focusing on high-reliability alarm protection

This model does not have an independent analog output function. The core focuses on temperature monitoring + dual-level high-reliability alarm protection. It adopts a sealed relay design, enhancing anti-interference ability and operational stability, suitable for critical equipment scenarios with extremely high requirements for alarm reliability. Through the 3300 series system bus, 6 real-time temperature data, alarm status, and fault information can be uploaded to the Thermo Fisher System 1 platform for remote monitoring and data management, meeting basic monitoring and protection needs.

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. It distinguishes between true temperature anomalies and sensor / circuit faults. The panel LEDs clearly indicate the fault type, and in conjunction with on-site 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 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 Thermo Fisher 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 via bus protocol to meet factory automation integration requirements, 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: 0–600℃

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: Complies with 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 1.4kg

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 / generator): Monitor turbine bearing temperatures, generator winding temperatures, lubricating oil temperatures, and sealing oil temperatures at multiple measurement points to prevent overheating-induced bearing burnout, insulation aging, and equipment damage; implement full-stage low-temperature protection during startup acceleration, normal operation, and shutdown rotation, trigger alarms or interlock shutdown upon overheating, ensuring safe and stable operation of the unit.

Petrochemical industry (large compressors / pump sets / heating furnaces): Monitor compressor bearing temperatures, pump set winding temperatures, heating furnace medium temperatures, and equipment shell temperatures, suitable for medium-low temperature and high-vibration industrial environments, to prevent equipment failures and production interruptions caused by overheating, ensuring continuous industrial production.

Metallurgical industry (large motors / fans / rolling mills): Monitor motor winding temperatures, fan bearing temperatures, rolling mill lubricating oil temperatures, and key equipment component temperatures in batches, implement dual-level safety relay alarm linkage for equipment operation interlocks, promptly warn of overheating faults, reduce unplanned downtime risks, and ensure stable and efficient operation of the metallurgical process.

VI. Installation and commissioning specifications

Installation requirements

Rack installation: Push into the vacant slot of the 3300 series rack smoothly, ensure that the rear connectors are fully engaged, tighten the panel fixing screws to avoid loose connections leading to 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 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.

Sensor installation: RTD probe is tightly attached to the surface of the measured equipment, fixed with thermal conductive silicone and a high-temperature clamp 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 calibration mode through the panel buttons, select Pt100 RTD type, calibrate the three-wire circuit resistance to ensure temperature measurement accuracy.

Alarm settings: Based on the equipment operation standards, set warning thresholds (such as 120°C) and danger thresholds (such as 150°C), adjust alarm delay (such as 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 RTD circuit has no fault indication, confirm that the alarm function is normal, and then put it into operation.

VII. Maintenance and fault troubleshooting

Daily maintenance

Regular inspection: Daily observe the panel temperature values, circuit status, and LED status, confirm no alarms or fault indications; check that the terminal connections of the module are not loose or oxidized, and the rack has good ventilation and heat dissipation. Annual Calibration: Use standard RTD to calibrate the temperature measurement accuracy every year, verify the alarm action value and delay accuracy of the relay, 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 Pt100 RTD wiring is loose, wrongly connected, or broken, and if the cable is damaged. Reconnect the wiring 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 is incorrect, if the cable is broken, and if the fault components need to be replaced.

Alarm triggered wrongly: Re-calibrate the alarm threshold and delay parameters, check if the RTD circuit resistance is abnormal, 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 **Pt100 platinum resistance (three-wire system, IEC 751 standard)** temperature sensor and dedicated RTD shielding cable. Mixing with thermocouples (such as K type) or two-wire / four-wire RTD is not allowed, 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 frame 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.