Bently 3300/25-03-05-05-03-00-02-00 Dual-Channel Accelerometer Vibration Monitoring Module – Detailed Product Description

I. Product Overview  

The Bently 3300/25-03-05-05-03-00-02-00 is a dual-channel accelerometer monitoring module from the Baker Hughes (formerly GE Bently Nevada) 3300 Series TSI (Turbine Supervisory Instrumentation) system, specifically designed for online monitoring of medium-to-low frequency absolute vibration in industrial large rotating machinery such as machine casings, bearing housings, gearboxes, and equipment foundations. As a standard functional unit within the 3300 series, this module features a dual-channel independent design with identical measurement ranges, compatible with standard piezoelectric accelerometers. It integrates high-precision signal conditioning, programmable filtering, dual-level alarm functions, sealed relay outputs, hardware self-diagnosis, and system bus communication capabilities. Supporting hot-swappable installation in standard 19-inch racks, it can be mixed and matched with other 3300 series modules in cabinet configurations. Widely used in thermal power, nuclear power, petrochemicals, metallurgy, air separation, and other industries, this module provides vibration condition monitoring, early fault warning, and safety protection for critical equipment including steam turbines, gas turbines, centrifugal compressors, large fans, and industrial pump units. Compliant with API 670 industry standards, it serves as a core component of rotating machinery condition monitoring systems.

II. Model Code Explanation (3300/25-AA-BB-CC-DD-EE-FF-GG)  

3300: Bently 3300 Series modular TSI platform featuring backplane centralized power supply, rack-mounted installation, and hot-swappable architecture.  

25: Function category code indicating dual-channel accelerometer monitoring.  

03 (AA): Channel A range configuration—0–5g (peak), compatible with standard 100mV/g piezoelectric accelerometers.  

05 (BB): Channel B range configuration—0–10g (peak), compatible with standard 100mV/g piezoelectric accelerometers.  

05 (CC): Filter combination configuration—high-pass 2.7Hz / low-pass 3kHz, suitable for medium-to-low frequency vibration monitoring applications.  

03 (DD): Certification configuration—CSA/NRTL/C certified, meeting North American industrial safety standards.  

00 (EE): Isolation configuration—no external isolation components; standard electrical isolation design.  

02 (FF): Relay configuration—dual sealed alarm relays enabling two-tier alarm output (warning and danger).  

00 (GG): Output configuration—standard configuration without analog output, focused on monitoring, alarming, and data uploading.

III. Core Features  

1. Dual-Channel Independent High-Precision Vibration Acquisition  

Equipped with two fully independent signal input channels, the module offers differentiated range settings: Channel A (0–5g) and Channel B (0–10g), ideal for monitoring medium-to-low frequency vibration points with varying intensity levels (e.g., bearing housings, medium-to-small gearboxes). Compatible with standard industrial piezoelectric accelerometers (100mV/g sensitivity), it operates in zero-peak (0–p) measurement mode, with an original frequency response of 2.7Hz–10kHz. After applying a 2.7Hz high-pass and 3kHz low-pass filter, the effective monitoring band becomes 2.7Hz–3kHz, accurately capturing medium-to-low frequency fault characteristics such as equipment looseness, bearing wear, gear meshing impacts, and structural resonance. The overall measurement accuracy is ≤±0.5% FS, with a resolution of 0.01g, enabling detection of minute vibration changes and early fault prediction. The module continuously monitors circuit faults such as sensor disconnection, short circuits, signal overloading, or underloading, and is robust against harsh conditions including dust, humidity, and strong electromagnetic interference.

2. Dual-Channel Sealed Relay Tiered Alarm Output Each monitoring channel can independently set two-level alarm thresholds—warning and danger—supporting local configuration via the front panel or remote configuration through a higher-level system. The alarm delay is adjustable from 0 to 10 seconds, effectively filtering out transient vibration disturbances and preventing false alarms. Equipped with dual epoxy-sealed SPDT relays featuring dustproof, moisture-resistant, and anti-vibration properties, the contacts support a rated load of 2A/24VDC. These relays can directly connect to on-site audio-visual alarms, DCS control systems, PLC logic circuits, or emergency shutdown interlock circuits, enabling multi-level safety alarms and interlocking protection upon vibration exceedance.

3. Optimized Programmable Signal Filtering for Mid-to-Low Frequencies  

The device features an internal programmable filter circuit, pre-configured as a combination of a 2.7Hz high-pass and 3kHz low-pass filter. The high-pass filter blocks DC components and extremely low-frequency environmental noise, while the low-pass filter eliminates high-frequency electromagnetic interference and mechanical shock noise, preserving mid-to-low frequency fault characteristics as effectively as possible. On-site adjustment of filter parameters via internal jumpers is supported (over 10,000 combinations of high-pass/low-pass options available), allowing adaptation to the frequency characteristics of different speed equipment and structural designs, thereby improving signal recognition accuracy and relevance.

4. Comprehensive Hardware Self-Diagnosis  

The system continuously monitors the backplane power supply voltage, internal hardware circuits, signal input loops, filtering units, and relay operation status. Upon detecting anomalies such as power failure, module hardware faults, sensor wiring issues, or signal irregularities, corresponding status indicator lights (OK/Alert/Danger/Fault) on the front panel immediately illuminate along with fault codes, helping maintenance personnel quickly identify the location and type of fault, reducing troubleshooting time. Hot-swappable design enables module replacement and maintenance without system downtime, significantly minimizing production losses.

5. System Integration and Anti-Interference Design  

The metal-shielded enclosure provides multiple electrical isolations between internal signal, power, and output circuits. Insulation strength between input and power circuits exceeds 2500VAC, offering excellent resistance to EMI/RFI electromagnetic interference. Seamless integration into the 3300 series backplane bus allows connection to Bentley’s System 1 equipment condition management platform, enabling remote uploading of real-time vibration data, alarm status, and fault records, as well as trend analysis, data storage, and diagnostics. Additionally, the device supports communication via bus protocols with plant DCS, PLC, SCADA, and other automation systems, integrating smoothly into the overall plant automation and control framework to meet modern industrial requirements for centralized monitoring and predictive maintenance.

IV. Detailed Technical Specifications  

Measurement and Input Parameters  

Number of Channels: 2 independent measurement channels.  

Compatible Sensors: Standard piezoelectric accelerometers with rated sensitivity of 100mV/g.  

Measurement Range: Channel A: 0–5g (peak); Channel B: 0–10g (peak).  

Frequency Response: Filtered: 2.7Hz–3kHz; Raw: 2.7Hz–10kHz.  

Measurement Accuracy: ≤±0.5% FS.  

Measurement Mode: Zero-to-peak (0–p).  

Input Impedance: ≥100kΩ.  

Electrical Parameters  

Power Supply: -24VDC (±10%), supplied uniformly via the system backplane.  

Total Power Consumption: ≤5W.  

Relay Output: 2×SPDT epoxy-sealed relays, contact rated load 2A/24VDC.  

Electrical Isolation: Insulation strength between input and power circuits ≥2500VAC.  

Analog Output: None.  

Environmental and Mechanical Parameters  

Operating Temperature: 0°C–+65°C.  

Storage Temperature: -40°C–+85°C.  

Operating Humidity: 5%–95% (non-condensing).  

Installation Method: 19-inch standard rack-mount slot installation, supports hot-swap. Dimensions: Approximately 203 mm × 330 mm × 51 mm.  

Device Weight: Approximately 0.85–1 kg.  

Protection Rating: IP20 (suitable for indoor control cabinet installation).  

Compliance and Certification  

Industry Standards: Complies with API 670 rotating machinery monitoring and protection standards.  

Safety Certification: CSA/NRTL/C (North American industrial safety certification).  

Electromagnetic Compatibility: CE certified, compliant with EN 61000-6-2/4 specifications.  

Environmental Directives: Meets RoHS environmental requirements.  

V. Typical Application Scenarios  

Power Industry: Vibration monitoring of turbine and generator bearing housings, as well as medium and small gearboxes in thermal and nuclear power plants; early warning for bearing wear, gear pitting, structural loosening, resonance, and other faults.  

Petrochemical Industry: Vibration monitoring of large centrifugal compressors, process pump units, and heavy-duty motor casings; suitable for dusty, oily, and humid environments to ensure continuous production.  

Metallurgical Industry: Vibration monitoring of large sintering equipment, induced draft fans, and rolling mill gearbox foundations; detects structural looseness, mechanical imbalance, and transmission mechanism failures.  

General Industrial Applications: Rotating machinery such as gas turbines, large pumping stations, air separation units, and medium-to-small gearboxes; provides mid- to low-frequency vibration data support for equipment condition assessment, fault analysis, and preventive maintenance.  

VI. Installation and Commissioning Guidelines  

Installation Requirements  

Rack Mounting: Gently insert the module into an available slot on the 3300 series rack, ensuring the rear connector fully engages. Tighten the panel mounting screws securely to guarantee reliable contact. Reserve sufficient ventilation space around the module to prevent heat buildup from affecting cooling performance and device operation.  

Sensor Installation: Piezoelectric accelerometers must be rigidly mounted at locations where vibration transfer is effective. The sensor base should be tightly bonded to the surface being monitored. Use dedicated shielded cables for signal wiring, grounding the shield only at one end within the control cabinet—never ground both ends to avoid circulating interference. Route cables away from high-power motors, inverters, and other strong electromagnetic sources.  

Wiring Standards: Clearly distinguish excitation lines, signal lines, and ground lines during sensor connection. Ensure all terminal connections are securely tightened to eliminate loose or intermittent contacts. For relay output circuits, clearly identify common terminals, normally open contacts, and normally closed contacts. After wiring, repeatedly verify circuit continuity.  

Commissioning Steps  

After powering up the backplane, the module automatically performs a self-diagnostic test. A steady OK indicator light on the front panel indicates successful hardware self-check. If the fault indicator lights up, sequentially check the power supply, wiring, sensors, and the module itself.  

Based on field equipment operating requirements, use the front-panel buttons to enter the parameter setup interface. Set alarm thresholds (warning and danger) and delay times for both channels, then save the parameters.  

Verify that the built-in filter settings meet mid- to low-frequency monitoring needs. Adjustments can be made via internal jumpers if necessary.  

After loading the equipment, observe whether vibration values on both channels remain stable without abnormal fluctuations, confirming no fault indications in the sensor loop.  

Manually simulate over-limit conditions to test relay activation status. Verify that alarm and interlock logic functions correctly before officially commissioning the module.  

VII. Maintenance and Troubleshooting  

Routine Maintenance  

During inspections, monitor the module’s front-panel indicator lights and real-time vibration readings to confirm no alarms or fault signals.  

Periodically inspect all terminal blocks for signs of looseness, oxidation, dust accumulation, or moisture. Check cable insulation for damage.  

Ensure proper rack ventilation. Clean the module surface regularly with a dry soft cloth. Do not allow liquids or metal debris to enter the device interior.  

Periodic Calibration  

Calibrate the module annually using a professional standard vibration test bench. Verify measured vibration values, alarm thresholds, and relay trip points to ensure accurate and reliable measurement and protection functions. Record and archive calibration data.  

Common Fault Troubleshooting OK indicator light off: First check whether the 24V DC power supply on the rack backplane is normal. Reinsert and remove the module to rule out poor contact issues. If ineffective, determine it as a hardware failure of the module and replace it directly.

Frequent vibration readings fluctuating: Focus on checking whether the sensor installation is loose, whether there are broken or short-circuited wires, and whether grounding is incorrect. Investigate potential strong electromagnetic interference sources at the site; replace the sensor or signal cable if necessary.

Frequent false alarms: Verify that alarm thresholds and delay settings are reasonable. Check whether filtering parameters do not match the low- to mid-frequency vibration characteristics of the equipment. Optimize wiring shielding measures.

Relay has no alarm output: Inspect relay circuit wiring and contact condition to identify open circuits or damaged contacts.

Sensor circuit fault indication: Check continuity of cables, sensor integrity, and wiring polarity segment by segment. Replace faulty components.

Eight. Usage Precautions

This product is a standard industrial non-explosion-proof device and must not be installed or used in flammable or explosive hazardous areas.

It is compatible only with 100 mV/g standard piezoelectric accelerometers. Connecting eddy current sensors, platinum resistance thermometers, thermocouples, or other types of sensors is strictly prohibited, as this may result in measurement failure or hardware damage.

Designed specifically for monitoring low- to mid-frequency absolute vibration of machine housings and structures; it cannot be used for shaft vibration or shaft displacement monitoring.

Do not disassemble the module housing, modify internal circuits, or replace non-original parts. Unauthorized modifications may cause permanent equipment damage and void the warranty.

Before performing wiring, maintenance, or disassembly operations, disconnect the main power supply to the rack to prevent electric shock or short-circuit accidents. Never plug in or unplug modules or touch internal terminals while the equipment is powered on.

When storing the equipment for extended periods, it is recommended to remove the module from the rack and store it in a dry, cool, and well-ventilated environment to avoid moisture, high temperatures, and dust accumulation, which can accelerate electronic component aging.