Bentley 3300/16-XX-05-01-00-00-00 Dual-channel Vibration / Clearance Monitor Detailed Product Description

I. Product Overview

The Bentley 3300/16 is a dual-channel radial vibration and shaft clearance (XY/Gap) monitoring module within the Bently Nevada 3300 series of rotating machinery protection systems. Model 3300/16-XX-05-01-00-00-00 is a standard industrial configuration that fully complies with API 670 standards. The equipment adopts a 19-inch standard rack-mounted, single-slot modular design, which can be directly integrated into the 3300 series dedicated rack, seamlessly matching with the same series of eddy current probes, preamplifiers, extension cables, and power components. It is mainly used for critical rotating equipment such as steam turbines, gas turbines, centrifugal compressors, large motors, generators, etc. in industries like power, petrochemicals, metallurgy, and oil and gas, simultaneously monitoring two independent radial vibrations (X/Y axes) and the average shaft clearance (distance between the shaft and the probe), replacing the traditional 3300/15 monitor and adding gap alarm functionality. It is the core device for vibration protection and bearing condition monitoring of the unit's shaft system.

II. Model Code Interpretation

3300/16 is the main product model, defined as a dual-channel vibration / clearance monitor; the following two-digit codes in the suffix define the hardware and functional configuration: 3300/16-XX-05-01-00-00-00. The meanings of each section are as follows:

Section 1: XX: Channel Configuration, XX represents dual vibration + dual clearance (XY/Gap) standard channels, supporting two independent eddy current inputs;

Section 2: 05: Measurement Range, 05 corresponds to the standard vibration range of 0–5mm (peak-to-peak), suitable for the routine vibration monitoring requirements of large rotating equipment;

Section 3: 01: Analog Output, 01 represents isolated 4–20mA current output, industrial standard signal compatible with DCS/PLC;

Section 4: 00: Alarm Logic, 00 is the factory default basic alarm configuration, including warning and danger relays, without customized voting logic;

Section 5: 00: Sensor Diagnosis, 00 is the standard loop diagnosis, supporting probe / cable / preamplifier fault detection;

Section 6: 00: Hardware Version, 00 is the original factory standard hardware, without special customization;

Section 7: 00: Certification and Additional Functions, 00 is the standard certification (CE/UL/CSA), without expansion functions.

III. Core Functions

1. Dual-channel Independent Vibration + Clearance Monitoring

Equipped with two completely independent measurement channels, capable of simultaneously connecting two sets of eddy current probes (X and Y in vertical direction), synchronously collecting ** radial vibration (peak-to-peak) and average shaft clearance (static distance)** data, achieving dual monitoring of XY-axis vibration and shaft position; a single channel failure does not affect the operation of the other channel, with redundant design to enhance reliability.

2. Vibration and Clearance Fault Warning

Real-time capture of rotor imbalance, misalignment, bearing wear, shaft bending, oil film vortexing, axial deviation, abnormal clearance, etc., providing early warnings for vibration over-limit, excessive / insufficient clearance, etc., avoiding rotor friction, shaft system damage, and unplanned shutdowns, etc., major accidents.

3. Graded Alarm and Interlock Protection

Integrated with 1 Alert + 1 Danger relay per channel, vibration and clearance threshold can be independently configured locally; relay contacts rated at 250VAC/3A, supporting normally open / normally closed settings, meeting the requirements for graded protection, emergency shutdown, and interlock logic of the unit.

4. Sensor Loop Self-Diagnosis The sensing loop composed of real-time inspection probes, extension cables, and preamplifiers automatically identifies faults such as open circuits, short circuits, signal over-range, probe failure, and abnormal gap voltages, triggering dedicated fault alarms and locking invalid data to avoid false monitoring and false interlocks.

5. On-site configuration and status display

Equipped with an LED digital display and operation keys on the front, it allows for on-site viewing of real-time vibration values, gap voltages, alarm/fault status, and channel OK status; supports full parameter configuration such as range, vibration/gap thresholds, output parameters, relay mode, frequency response, etc., with automatic storage and no data loss upon power failure.

6. Standard analog output

Each channel independently provides isolated 4–20mA current output (corresponding to a 0–5mm vibration range), linearly corresponding to the measured value, which can be directly connected to DCS, PLC, SCADA, etc., to achieve remote data collection, trend recording, and centralized monitoring.

7. Programmable frequency response

Supports two frequency range configurations: **4–4000Hz (240–240000 cpm)** for high-speed turbines; **1–600Hz (60–36000 cpm)** for low-speed / heavy-load equipment, meeting the vibration characteristics requirements of different units.

IV. Working Principle

Based on the non-contact measurement principle of eddy current: The 3300 series eddy current probes are connected to a high-frequency alternating current, when the probe approaches the metal shaft surface, the shaft surface induces eddy currents, and the change in the gap between the probe and the shaft directly alters the intensity of the eddy currents and the equivalent impedance of the probe (Bently Nevada). The weak signal corresponding to the gap is transmitted through the extension cable to the preamplifier, which completes signal amplification, shaping, and temperature compensation, and outputs a linear DC voltage signal to the 3300/16 module (Bently Nevada). The internal circuit of the module separates the voltage signal into dynamic vibration components (peak-to-peak) and static gap components (average spacing), comparing them with the preset vibration/gap thresholds to drive relays to output alarm / trip interlock signals; at the same time, it converts the vibration value into a 4–20mA standard current signal for external output. The two channels operate independently and cooperate with loop diagnosis to achieve redundant monitoring and reliable protection.

V. Main Technical Parameters

1. Measurement System

Channels: 2 independent eddy current signal inputs (X/Y axes), synchronous monitoring of vibration + gap;

Compatible sensors: 3300XL series 5mm/8mm/11mm eddy current probes, compatible with 330180 preamplifier, 330130 extension cable (Bently Nevada);

Input impedance: 10kΩ;

Gap voltage range: -4VDC to -20VDC (standard -12VDC).

2. Measurement Performance

Vibration range: Standard 0–5mm (peak-to-peak), configurable 0–2mm/0–10mm;

Gap range: 0–4mm (corresponding to gap voltage -4VDC to -20VDC);

Accuracy: Full-scale error at normal temperature ≤ ±1%, single-point accuracy ±0.02mm;

Frequency response: Programmable 4–4000Hz or 1–600Hz (-3dB);

Resolution: 0.001mm, meeting the requirements of high-precision vibration monitoring.

3. Output Characteristics

Analog output: Each channel isolated 4–20mA (corresponding to 0–5mm), output load ≤ 500Ω;

Relay output: Each channel 1 warning, 1 danger, contact 250VAC/3A, programmable open / closed.

4. Electrical and Environmental Power supply: -24VDC (±10%), programmable switch - 18VDC;

Power consumption: typical 6W;

Operating temperature: 0℃–60℃;

Storage temperature: -40℃–85℃;

Relative humidity: ≤95% (no condensation);

Certifications: CE, UL, CSA, compliant with API 670.

5. Mechanical Characteristics

Structure: Standard 19-inch rack, single slot (height 83mm);

Weight: approximately 1.5kg;

Protection: Industrial-grade anti-vibration, anti-EMI design, suitable for complex working conditions.

Six. Installation and System Configuration

1. Rack Installation

Directly mount onto the 3300 series dedicated rack, single slot fixed, convenient for installation and disassembly, suitable for industrial control room standard cabinet layout, neat wiring.

2. Sensor Installation

Two eddy current probes are vertically (X/Y) aligned with the surface of the shaft, symmetrically arranged, the initial gap is set at the midpoint of the sensor's linear range (corresponding to a gap voltage of -12VDC), ensuring effective vibration and gap measurement throughout the Bently Nevada (Bently Nevada Nevada).

3. On-site Configuration

After power-on, enter the configuration menu through the panel buttons, sequentially set the vibration range, gap range, warning/danger threshold, frequency response, 4–20mA correspondence, relay contact type, fault alarm mode, etc., parameters are automatically saved, no need for upper software to complete on-site debugging.

4. Wiring Specifications

Divided into power wiring (-24VDC), sensing signal wiring (probe / preamplifier), relay interlock wiring, 4–20mA analog output wiring, strictly distinguish polarity and signal type according to the body markings to ensure reliable wiring.

Seven. Typical Application Scenarios

Power industry: steam turbine generator sets, gas turbine generator sets, monitor X/Y axis vibration and shaft gap, protect bearings, shaft seals and flow components;

Petrochemical industry: centrifugal compressors, process turbines, large pump sets, prevent vibration exceeding limits causing rotor-stator scraping, bearing burnout;

Metallurgical industry: large fans, motors, generators, monitor shaft system vibration and gap, avoid imbalance and misalignment-induced equipment failures;

Other fields: high-speed turbine machinery, screw compressors, cover the entire process of vibration and gap protection for unit start-stop, load regulation, steady operation.

Eight. Product Advantages

1. Dual parameter monitoring of vibration + gap

Single module simultaneously realizes radial vibration and shaft gap monitoring, high functional integration, reduces hardware quantity and installation cost, fills the gap of no gap alarm in traditional 3300/15.

2. High reliability redundant design

Dual-channel independent monitoring + complete sensor circuit diagnosis, hardware redundancy + software fault tolerance, significantly reduce single-point failure-induced false actions, ensure continuous operation of the unit.

3. High precision and wide frequency adaptation

Eddy current non-contact measurement without mechanical wear, combined with high-precision signal processing circuit, measurement is accurate, long-term drift is small; programmable frequency response adapts to high-speed / low-speed various rotating equipment.

4. Flexible system integration

4–20mA standard current output + multiple relay interfaces, strong versatility, seamless integration with mainstream industrial control systems, low integration difficulty.

5. Convenient operation and maintenance

Full-function on-site display and configuration, on-site can quickly view status, determine faults, modify parameters, daily maintenance is efficient; modular design facilitates spare parts replacement, shortens downtime.

Nine. Supporting Components

Requires coordination with the following components to form a complete monitoring system:

Eddy current probe: 3300XL series 5mm/8mm/11mm specifications, select Bently Nevada (Bently Nevada Nevada) according to shaft diameter and installation space. Preamplifier: 330180 series, supplies power to the probe and preprocesses the signals - Bently Nevada;

Extension cable: 330130 series high-frequency coaxial cable, extends the signal transmission distance - Bently Nevada;

System rack: 3300 series standard rack, provides installation support;

Power module: -24VDC dedicated power supply, supplies power to the monitor and sensing system.