Bentley 3300/55 Dual-Channel Speed Vibration Monitoring Module

I. Product Overview

The Bentley 3300/55 is a standard dual-channel speed vibration monitoring module of the 3300 series TSI (Turbo Generator Instrumentation) under Baker Hughes (formerly GE), used for continuous online monitoring of absolute vibration speed of rotating / reciprocating mechanical bearing housings. It receives signals from seismic speed sensors (Velomitor, HTVS, etc.) and measures the peak vibration speed in real time. It can detect faults such as imbalance, misalignment, bearing wear, and structural resonance early, and is widely used in vibration protection and condition monitoring of key equipment such as turbines, compressors, fans, pumps, motors, etc. in the power, petrochemical, metallurgical, and oil and gas industries. The module is installed in a 19-inch standard rack and supports hot swapping, allowing for replacement without power interruption, and is compatible with 3300 series racks and power supply systems.

II. Model Coding Rules (3300/55-XX-XX-XX-XX-XX-XX-XX-XX-XX)

3300: Bentley 3300 series modular TSI system, 19-inch rack, centralized power supply, supports hot swapping and mixed installation of multiple modules.

55: Function code, dual-channel speed vibration monitoring module, processes two seismic speed sensor signals, measures absolute vibration speed.

The 1st digit: Sensor sensitivity (e.g., 01 = 500 mV/in/s; 02 = 200 mV/in/s; 03 = 100 mV/in/s).

The 2nd digit: Frequency response (e.g., 01 = 2–300 Hz; 04 = 10–1000 Hz; 05 = 10–2000 Hz).

The 3rd digit: Channel 1 range (e.g., 01 = 0–1.0 mm/s pk; 02 = 0–2.0 mm/s pk; 12 = 0–12.7 mm/s pk).

The 4th digit: Channel 2 range (same as Channel 1, can be independently configured).

The 5th digit: Keyphasor interface (00 = no; 01 = yes).

The 6th digit: Analog output (00 = no; 03 = 4–20 mA; 04 = 0–10 V).

The 7th digit: Relay configuration (e.g., 01 = 2 channels per channel + common OK; 04 = 2 channels per channel without OK; 05 = 2 channels per channel + common OK).

The 8th digit: Communication interface (00 = no; 01 = RS485; 02 = Ethernet).

The 9th digit: Special function (00 = standard; 01 = high-temperature version; 02 = rugged version).

III. Core Functions

Dual-channel independent speed measurement

Two completely independent and synchronized sampling channels, compatible with Bentley Velomitor, high-temperature Velomitor (HTVS), Seismoprobe, etc. Real-time monitoring of absolute vibration speed peaks of bearing housings / shells, electrical isolation between channels, single-point failure does not affect the other channel, ensuring continuous monitoring.

Wide-band programmable filtering

Built-in second-order high-pass / low-pass filter, standard frequency response covers 2 Hz–2000 Hz, can be configured by jumper or software for cutoff frequency. Low-frequency band (2–300 Hz) is suitable for imbalance, misalignment, foundation loosening; mid-frequency band (10–1000 Hz) is suitable for bearing wear, gear meshing; high-frequency band (10–2000 Hz) is used for structural resonance and high-frequency impact monitoring.

High-precision signal processing 24-bit ADC sampling, 256 samples per channel per second, dynamic range > 80 dB. Measurement accuracy ≤ ±1% of reading, resolution 0.1 mm/s, supports integration/differentiation conversion of speed/acceleration/displacement signals, meeting different fault analysis requirements.

Comprehensive self-diagnosis and fault identification

24-hour monitoring of sensor open circuit, short circuit, signal over-limit, sensitivity abnormality, module power failure, etc. Differentiate mechanical vibration faults from sensor/loop faults, reducing false alarms and false interlocks; panel LED displays OK, bypass, alarm, dangerous state.

Two-level programmable alarm and relay output

Each channel independently sets the ** warning (Alert) / dangerous (Danger) ** two-level thresholds, alarm delay 0–10 seconds programmable, filtering transient fluctuations. Relay is SPDT passive contact point, rated 250 V AC/3 A, 30 V DC/3 A, can directly drive sound and light alarm, unit interlock or connect to DCS/PLC.

Local display and local configuration

Front panel with dual-channel light column meter, real-time display of vibration velocity value; equipped with OK, Alert, Danger, Bypass LED indicators. Through panel buttons, local set parameters such as range, filtering, alarm threshold, delay, etc., without need for upper computer.

Strong anti-interference and system integration

Metal shielding shell, input/output/power electrical isolation between high voltage, anti-common-mode interference ≥ 2500 V AC, suitable for frequency converters, high-voltage equipment in strong electromagnetic environment. Compatible with 3300 system bus, can be connected to System 1 status monitoring software, realize remote configuration, data storage, trend analysis and fault traceability.

IV. Technical Parameters

Measurement Parameters

Number of channels: 2 independent isolated channels.

Compatible sensors: Velomitor (100/200/500 mV/in/s), HTVS, Seismoprobe.

Measurement range: 0–1.0 / 2.0 / 5.0 / 12.7 mm/s pk (optional).

Frequency response: 2–300 Hz, 10–1000 Hz, 10–2000 Hz (-3 dB).

Sampling rate: 256 samples per channel per second.

Accuracy: ≤ ±1% of reading (25℃), resolution 0.1 mm/s.

Signal conversion: speed ↔ acceleration ↔ displacement (integration / differentiation).

Alarm: two-level (warning / dangerous) per channel, alarm delay 0–10 seconds programmable.

Electrical parameters

Working power supply: -24 V DC (±10%), backplane power supply of the frame.

Power consumption: ≤ 3 W, typical 1.5 W.

Input impedance: matched to Velomitor sensor standard impedance.

Relay output: 2 SPDT per channel, optional common OK relay.

Analog output (optional): 4–20 mA or 0–10 V, isolated output.

Isolation performance: input/output/power isolation ≥ 2500 V AC.

Environmental and mechanical

Operating temperature: -30℃ ~ +65℃ (standard).

Storage temperature: -40℃ ~ +85℃.

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

Installation: 19-inch standard frame slot, supports hot swapping.

Size: 254 mm × 165 mm × 63.5 mm.

Weight: approximately 1.2 kg.

Protection level: IP20 (in the control cabinet). 

Certification and compliance Industry standard: Compliant with API 670 (version 4/5).

Electromagnetic compatibility: CE, CSA certification, compliant with EN 61000-6-2/4.

Safety: UL, RoHS compliance.

Explosion-proof: Non-explosion-proof design, only applicable to non-hazardous areas.

VII. Structural Design

The module adopts a standard rack structure, with a compact layout, divided into the front panel, main circuit, and rear terminals. The front panel integrates the light column meter, LED indicator lights, and operation keys, facilitating on-site viewing and configuration. The interior consists of two completely independent signal processing units, with no electrical connection between channels, and single-point failure does not spread. The rear terminals are clearly zoned, including sensor input, relay output, power supply, and communication interfaces, with clear markings, facilitating wiring and maintenance. The gold-plated connectors ensure reliable hot-swapping, and replacing the module does not require downtime.

VIII. System Compatibility

Hardware Compatibility

Rack and power supply: Compatible with 3300 series 19-inch racks, power modules, and system monitoring modules, and can be installed with displacement, rotational speed, temperature, etc. modules.

Sensors: Fully compatible with Bently Velomitor, HTVS, Seismoprobe, and the same specifications can be directly interchanged.

Output connection: Relay contacts can be connected to audible and visual alarms, interlock circuits, DCS/PLC dry contacts; analog output can be connected to recorders or DCS analog inputs.

Software Compatibility

Configuration software: 3300 series dedicated configuration software, supports remote parameter configuration, alarm logic editing, and firmware upgrade.

Monitoring software: System 1 equipment status monitoring software, realizes real-time data, trend, fault records, reports, and remote access.

IX. Typical Application Scenarios

Power industry: Vibration monitoring of bearing seats in thermal power / gas turbine units, warning of imbalance, misalignment, bearing wear, resonance, to ensure the safety of the main unit.

Petrochemical industry: Vibration monitoring of centrifugal compressors, process turbines, high-speed pump groups in non-explosion-proof areas, preventing unplanned shutdowns.

Metallurgical industry: Monitoring of high-temperature fan, sintering main exhaust fan, high-speed motor bearing seats, predicting bearing failure, gear faults, resonance.

General industry: Online monitoring, fault diagnosis, and interlock protection of high-speed large rotating machinery (grinding mills, fans, pump groups) in cement, papermaking, water treatment, etc.

IX. Installation and Maintenance Specifications

Installation Requirements

Rack installation: Insert smoothly into the 3300 rack slot, ensure that the connectors are fully engaged, and tighten the panel screws.

Sensor wiring: Connect Velomitor cables according to channel numbers, single-ended grounding of the shielding layer to reduce interference.

Alarm wiring: Connect the relay contacts to the alarm/interlock circuits according to the drawings, distinguish warning, danger, and OK contacts.

Power-on configuration: Confirm normal -24 V DC, then set the range, filtering, alarm threshold, and delay through the panel or software.

Sensor installation: Fix vertically or horizontally on the rigid part of the bearing seat, firmly attached, and cable fixed and protected.

Daily maintenance

Inspection: Observe the panel display and LED, confirm normal data and no fault alarms; check that the terminals are not loose, oxidized, or overheated.

Calibration: Calibrate the accuracy annually using a standard vibration table, in compliance with API 670 requirements.

Cleaning: Regularly clean the module and rack of dust to ensure ventilation and heat dissipation.

Spares: Replacement of modules, sensors, or cables must use Bently original parts to avoid compatibility issues.

X. Usage Precautions

This module is non-explosion-proof. It is strictly prohibited from being used in flammable and explosive hazardous areas.

It must be equipped with Bently original Velomitor/HTVS sensors, and other specifications must not be mixed. Otherwise, the sensitivity will not match and the measurement will fail. The sensors should be installed on the rigid parts of the bearing housing, avoiding thin-walled or non-rigid areas to prevent distortion of vibration transmission.

It is prohibited to disassemble the module, modify the circuit or change the calibration parameters of the sensor without authorization. Otherwise, the equipment will be damaged and the warranty will be invalid.

Before wiring, maintenance or replacing the module, the power supply of the frame must be cut off to prevent short circuits and electric shock.

The alarm threshold and delay must be strictly set according to the process of the unit. Improper parameters will lead to the failure of protection or frequent false alarms.

The installation location should be far away from strong electromagnetic interference sources such as frequency converters, transformers and high-voltage cabinets to reduce signal interference.