Bentley 3300/61 Dual-Channel Vector (XY Axis) Vibration Monitoring Module - Detailed Product Description

I. Product Overview

The Bentley 3300/61 is a dual-channel vector (XY axis) vibration monitoring module of the 3300 series TSI (Turbo Generator Instrumentation) system under Baker Hughes. It is primarily used for high-precision online monitoring of the rotor axis trajectory (Orbit) and vector vibration of large rotating machinery. It is a key unit for rotor dynamics fault diagnosis. The module adopts a standard 19-inch rack-mounted modular design, supports hot swapping, and can be disassembled, replaced, and reinstalled without power interruption, compatible with the 3300 series racks and power supply system. The 3300/61 is equipped with 3300 XL series eddy current probes (X and Y orthogonal installation), real-time processing of the two-dimensional motion trajectory of the rotor, vibration amplitude, phase, and 1×/2× frequency division vectors, featuring high-precision measurement, trajectory analysis, fault diagnosis, and alarm interlock functions, strictly following API 670 standards. It is widely used in non-explosive areas of power, petrochemical, and metallurgical industries, compatible with turbine, gas turbine, centrifugal compressors, and generator sets with sliding bearings, for online identification and protection of complex faults such as axis position monitoring, oil film wobbling/oscillation, rotor imbalance, misalignment, and rubbing. 

II. Model Coding Rules

3300: This is the classic 3300 series modular TSI system of Bentley, installed on a standard 19-inch rack, supporting multi-module combination expansion, centralized power supply, and hot swapping.

61: Function code, defined as a dual-channel vector (XY axis) vibration monitoring module, specifically processing two orthogonal eddy current probe signals, generating axis center trajectory and vector vibration data.

The following 7-digit configuration codes (3300/61-XX-XX-XX-XX-XX-XX-XX):

The 1st digit (probe specification): 01 = 5mm probe; 02 = 8mm probe; 03 = 11mm probe; 04 = 11mm long-stroke probe.

The 2nd digit (range and sensitivity): 01 = 0~2mm peak-to-peak, 7.87V/mm; 02 = 0~5mm peak-to-peak, 3.94V/mm.

The 3rd digit (frequency response): 01 = 1~1000Hz; 02 = 1~500Hz; 03 = 1~2000Hz.

The 4th digit (Keyphasor interface): 00 = None; 01 = Yes (speed synchronization input).

The 5th digit (analog output): 00 = None; 01 = 4-20mA; 02 = 0-10V.

The 6th digit (communication interface): 00 = None; 01 = RS232; 02 = Ethernet.

The 7th digit (special function): 00 = Standard; 01 = High-temperature compatible.

III. Core Functions

Dual-channel orthogonal vector measurement (XY axis): Two input channels are completely independent and synchronized for sampling, compatible with eddy current probes installed vertically in the X and Y directions, real-time collection of radial two-dimensional vibration data, generating axis center trajectory (Lissajous figure), vector amplitude, phase angle, and 1×/2× frequency division vectors, accurately reflecting the dynamic motion characteristics of the rotor. Electrical isolation between channels, single-point failure does not affect the operation of the other channel, ensuring continuous monitoring.

Axis center trajectory and vector analysis: Built-in high-speed signal processing algorithm, supports real-time axis center trajectory generation, vector trend tracking, phase analysis, and frequency division extraction, can clearly distinguish typical fault trajectory forms such as oil film wobbling, oil film oscillation, rotor imbalance, misalignment, and dynamic static rubbing, providing direct diagnostic basis for complex rotor dynamics problems. High-precision signal acquisition and processing: Utilize a 24-bit high-speed ADC for sampling, with 512 samples per channel per second. The measurement linear error is ≤ full scale ±0.5%, phase accuracy is ≤ ±1°, and the minimum resolution is 0.01mm. It can stably capture minute axis center offsets and vibration changes. It is compatible with the full series of 3300 XL 5mm/8mm/11mm eddy current probes, extension cables, and preamplifiers. The sensing components can be directly interchangeable without the need for re-calibration.

Comprehensive fault self-diagnosis: Built-in OK self-check circuit, 24-hour monitoring of probe, extension cable, and preamplifier for faults such as open circuit, short circuit, signal over-limit, and gap anomaly. Accurately distinguish between mechanical equipment faults and sensing circuit faults, reducing the probability of false alarms and false interlocks. The panel LED synchronously displays channel OK, faults, and bypass status, facilitating on-site problem identification.

Programmable multi-level alarm and interlock: Each channel can independently set two-level alarm thresholds for vector amplitude and phase angle (warning / danger). Alarm delay is programmable from 0 to 10 seconds, and filtering of instantaneous signal fluctuations is supported. The entire machine is equipped with 4 SPDT passive relay contacts (2 contacts per channel), with a rated load of 250V AC/3A and 30V DC/3A. It can be directly connected to the sound and light alarm circuit and the unit safety interlock circuit to achieve fault-level protection.

Local status display and operation: The front panel integrates a high-contrast LCD light column display, which can simultaneously display X/Y axis vibration amplitude, axis center trajectory contour, and alarm status. Combined with operation keys, it can complete alarm threshold, range, and trajectory display mode parameter settings on-site without relying on the upper computer. The operation is intuitive and convenient.

Strong anti-interference and system integration: Adopt a metal shielding structure, electrical isolation of input, output, and power supply circuits, resisting electromagnetic interference from frequency converters and high-voltage equipment, with anti-common-mode interference ≥ 2500V AC. Supports internal bus communication of the 3300 system and is compatible with System 1 monitoring software, enabling remote parameter configuration, trajectory data storage, trend analysis, and fault traceability, supporting the full life cycle management of the equipment.

VII. Technical Specifications Measurement parameters

Number of channels: 2 fully independent and synchronized isolated channels (orthogonal X-axis and Y-axis).

Sensor compatibility: 3300 XL 5mm/8mm/11mm eddy current probes, extension cables, preamplifiers.

Measurement range: Standard 0~2mm peak-to-peak (can be scaled on-site to 0~5mm).

Sensitivity: Standard 7.87V/mm (0~2mm range), 3.94V/mm (0~5mm range).

Frequency response: 1~1000Hz (-3dB), supports 1×/2× band-pass filtering.

Sampling rate: 512 samples/second per channel.

Measurement accuracy: Linear error ≤ ±0.5% of full scale, phase accuracy ≤ ±1°, resolution 0.01mm.

Alarm settings: Two-level alarms for vector amplitude and phase angle per channel, with delay of 0~10 seconds programmable.

Electrical parameters

Power supply: -24V DC (allowable fluctuation ±10%), powered by the backplane of 3300 rack.

Power consumption: ≤3.5W, maximum working current 18mA.

Input impedance: matches the standard input impedance of 3300 XL preamplifier.

Relay output: 4 SPDT non-polarized dry contacts, 250V AC/3A, 30V DC/3A.

Analog output (optional): 4-20mA DC (accuracy ±0.1% of full scale), 0-10V DC.

Isolation performance: High-voltage electrical isolation between input/output/power supply, anti-common-mode interference ≥ 2500V AC.

Environmental and mechanical parameters

Operating temperature: -40℃~+70℃ (high-temperature compatible type can reach + 85℃).

Storage temperature: -40℃~+85℃.

Relative humidity: 0%~95% (no condensation).

Installation method: Standard 19-inch rack slot installation of 3300 series, supports hot swapping.

Shell material: Metal panel + flame-retardant engineering plastic, shock-resistant, corrosion-resistant, oil-resistant.

Protection level: IP20 (installed inside control cabinet).

Size: 254mm×165mm×63.5mm (standard 3300 module size).

Weight: Approximately 1kg.

Certification and compliance

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

Electromagnetic compatibility: CE certification, complies with EN 61000-6-2, EN 61000-6-4 standards.

Safety certification: UL, RoHS compliance.

Explosion-proof rating: Non-explosion-proof design, no built-in safety barrier, only applicable to non-flammable and non-explosive areas.

V. Structural Design

The module adopts a standard rack-mounted modular structure, compact layout, divided into front panel, internal main circuit, and rear terminal block. It is convenient for installation, wiring and maintenance.

Front panel: integrates LCD light column display (synchronously displays X/Y axis amplitude and trajectory outline), power/OK/alarm/fault LED indicators and operation keys, can locally view real-time data, alarm status, complete basic parameter configuration such as range, alarm threshold, trajectory display mode, and operation is intuitive and convenient.

Internal main circuit: divided into two completely independent synchronous signal processing units, corresponding to X and Y channels, each unit integrates signal conditioning, high-speed sampling, filtering, vector operation, trajectory generation, alarm comparison and relay drive circuit, there is no electrical connection between channels, a single-point failure does not affect the operation of the other channel. Back terminal block: Zone layout, clearly dividing X/Y axis probe input terminals, 4-channel relay alarm terminals, optional analog output terminals, power terminals, and system communication interface. Terminal markings are clear, wiring is neat, facilitating on-site wiring, line inspection, and maintenance.

Hot-swappable design: The module and the backplane of the rack use gold-plated connectors, with reliable contact, supporting online insertion and removal. Replacing the module does not require shutting down the entire TSI system, reducing the impact of maintenance on the operation of the unit.

VII. System Compatibility

Hardware Compatibility

Rack and Power Supply: Perfectly compatible with 3300 series standard 19-inch racks, system power modules, system monitoring modules. Modules with the same series of vibration, displacement, speed, valve position and other functions can be installed and work collaboratively.

Sensing Components: Fully compatible with the 3300 XL series of 5mm/8mm/11mm electromagnetic induction probes, extension cables, and preamplifiers. Sensors with the same specifications can be directly interchanged without re-calibration.

Output Connection: Relay contacts can be connected to audible and visual alarms, unit interlock circuits, DCS/PLC dry contact inputs; optional analog output can be connected to DCS/PLC analog input modules to achieve centralized monitoring of vibration data.

Software Compatibility

Configuration Software: Compatible with 3300 series dedicated configuration software, supporting remote parameter configuration, alarm logic editing, trajectory display mode setting, and firmware upgrade.

Monitoring Software: Compatible with System 1 equipment status monitoring software, capable of real-time axis trajectory collection, vector trend analysis, fault record storage, report generation, and remote access, supporting rotor dynamics fault diagnosis and equipment full life cycle management.

VIII. Typical Application Scenarios

Power Industry: Rotating shaft axis trajectory and vector vibration monitoring for turbine rotors in thermal power plants, nuclear power plants, and gas turbines, real-time identification of oil film turbulence, oil film oscillation, rotor imbalance, misalignment, and dynamic friction between rotor and stator, warning of shaft instability risks, ensuring safe and stable operation of the unit.

Petrochemical Industry: Axis position and vibration vector monitoring for centrifugal compressors, process turbines, and large steam turbines in non-explosion-proof areas, avoiding unplanned shutdowns caused by rotor faults, bearing wear, oil film instability, and ensuring continuous production.

Metallurgical Industry: Axis trajectory monitoring for high-speed rotating equipment such as blast furnace fans, sintering main exhaust fans, and large drive motors, predicting bearing wear, rotor imbalance, and shaft misalignment hazards, reducing equipment failure rates.

General Industry: Large rotating machinery in industries such as cement, papermaking, and water treatment, such as grinding mills, fans, pump sets, etc., conducting online monitoring of axis status, rotor dynamics fault diagnosis, and safety interlock protection, extending equipment service life, and reducing operation and maintenance costs. Installation of probes: The X and Y probes must be installed strictly perpendicularly and orthogonally. The static gap for the 5mm probe is 0.5mm, for the 8mm probe 1.0mm, for the 11mm probe 1.27mm. The probe end face must be perpendicular to the surface of the measured shaft. The cable must be fixed and protected to avoid vibration wear.

Daily maintenance

Inspection and check: Regularly observe the LCD display on the panel and the LED indicator lights to confirm that the X/Y axis vibration and trajectory display are normal, and that the channel has no faults. Check if the connection terminals are loose, oxidized, or overheated. Address any potential issues promptly.

Precision calibration: Every year, use a standard gap calibration device to calibrate the module's measurement accuracy and phase, ensuring compliance with API 670 standards.

Clean cooling: Regularly clean the dust accumulation on the module surface and the rack slots to ensure good ventilation and cooling, preventing dust-induced short circuits or poor cooling failures.

Replacement of spare parts: When replacing the module, probe, or cable, only use the original Bentley product of the same model. Do not use non-original accessories to avoid compatibility issues or measurement errors.

IX. Usage precautions

This module is not designed for explosion-proof and has no built-in safety barrier. It is strictly prohibited to install and use it in flammable and explosive, or areas with combustible gases or dust.

It must be used in conjunction with the original 3300 XL series eddy current sensing system. The probe specifications (5mm/8mm/11mm) must be strictly matched with the module configuration. Do not mix them; otherwise, it will result in mismatched ranges and sensitivities, and measurement failure.

The X and Y probes must be installed strictly perpendicularly and orthogonally. The static gap must be set strictly according to the corresponding specifications. Inappropriate gaps will cause trajectory distortion and increased measurement errors.

Do not disassemble the module, modify the internal circuitry, or change the factory-calibrated length of the sensing cable. Illegal operations will cause equipment damage and loss of product warranty rights.

Before wiring, maintenance, or module replacement operations, cut off the power supply of the rack to prevent short circuits, electric shock, and other safety accidents.

Alarm thresholds, delays, etc. must be set strictly according to the process requirements of the unit. Improper settings will cause protection failure or frequent false alarms.

The installation position of the module should be as far away as possible from power frequency converters, transformers, high-voltage distribution cabinets, etc., which are strong electromagnetic interference sources. Reduce the influence of external interference on the measurement signal.