Bentley 3300/16-14-01-01-00-00-00 Dual-channel Vibration / Clearance Monitor Detailed Product Description

I. Product Overview

The Bentley 3300/16 belongs to the 3300 series of rotating machinery protection system. It is a rack-mounted dual-channel radial vibration and shaft clearance comprehensive monitoring module. The current model 3300/16-14-01-01-00-00-00 is a standard customized configuration. The product strictly follows the API 670 industry standard. The equipment adopts a 19-inch standard cabinet single-slot modular design, which can be directly installed in the 3300 series system rack, and can be fully compatible with the same series eddy current probes, preamplifiers, extension cables, and power modules. This equipment is mainly used in steam turbines, gas turbines, centrifugal compressors, large generators, industrial fans, heavy-duty pump sets, and other key rotating machinery in the power, petrochemical, metallurgy, and other fields. It can simultaneously complete the real-time monitoring of two paths of shaft radial vibration and static shaft clearance, fault alarm, and safety interlock. It is the core equipment for protecting the bearing condition and shaft system operation status of rotating equipment.

II. Model Code Interpretation

3300/16 is the main product model, representing a dual-channel vibration and shaft clearance monitor. The suffix consists of seven two-digit segments, which define the hardware configuration, measurement range, output type, alarm logic, diagnostic function, hardware version, and certification configuration. The meanings of each segment of this model are as follows.

The first segment code 14 represents the channel function and measurement type configuration, which is suitable for two independent eddy current sensor inputs and supports the simultaneous collection of radial vibration peak-to-peak values and the static gap signal from the probe to the shaft body. It is a standard XY-axis vibration monitoring configuration.

The second segment code 01 represents the preset measurement range, corresponding to a vibration range of 0 to 1 mm peak-to-peak, suitable for small-sized rotating machinery with strict vibration amplitude requirements and high-speed shaft systems.

The third segment code 01 represents the analog output specification, using isolated 4-20mA direct current current output, which is an industrial standard signal and can be directly connected to DCS, PLC, SCADA, etc. industrial control systems.

The fourth segment code 00 represents the alarm logic configuration, using the factory default basic alarm logic, without additional customized channel voting, special interlock expansion functions.

The fifth segment code 00 represents the sensor circuit diagnostic configuration, enabling the standard full circuit diagnostic function, which can monitor the probe, extension cable, and preamplifier status.

The sixth segment code 00 represents the hardware version, being the original factory standard general hardware version, without special hardware modification and customization.

The seventh segment code 00 represents additional functions and certifications, equipped with CE, UL, CSA international universal certifications, without additional additional functions and special industry customization requirements.

III. Core Functions

1. Dual-channel Comprehensive Monitoring

The equipment has two independent measurement channels that can be externally connected to two sets of vertically arranged eddy current probes to simultaneously complete the synchronous collection and calculation of two paths of axial vibration and static shaft clearance. The two channels do not interfere with each other, and a single channel failure will not affect the normal operation of the other channel. The dual-channel monitoring architecture enhances the stability of the entire system operation.

2. Equipment Fault Early Warning

Continuous tracking of the axial radial vibration amplitude and the static gap changes of the shaft, which can effectively identify common fault hazards such as rotor imbalance, shaft misalignment, bearing wear, oil film instability, shaft displacement deviation, and probe installation abnormalities, and issue early warning signals to avoid vibration over-limit, shaft friction, bearing burnout, etc., ensuring the safe and stable operation of the unit.

3. Graded Alarm and Interlock Protection Each channel is independently configured with one warning relay and one danger relay. The vibration threshold and gap threshold can be independently set through local buttons. The rated parameters of the relay contacts are 250VAC and 3A. The contact mode can be set as normally open or normally closed. The equipment can be configured with hierarchical alarms, unit interlocks, and emergency shutdown logic according to the on-site process requirements.

4. Self-diagnosis of sensor circuit faults

The device is equipped with a complete circuit monitoring program that can detect the entire sensing circuit composed of the probe, extension cable, and preamplifier in real time. Once problems such as open circuit, short circuit, signal beyond the measurement range, or abnormal power supply occur, the equipment will immediately trigger a sensor fault alarm and mark the abnormal channels to prevent false alarms or interlocks caused by abnormal signals.

5. Local display and parameter configuration

The body is equipped with an LED digital display and physical operation buttons. Maintenance personnel can directly view real-time vibration values, static gap voltage, current alarm status, and channel operation status on-site. The equipment supports local configuration of all parameters such as range, alarm threshold, analog output correspondence, frequency response, and relay action mode. All settings parameters are automatically saved, and the data will not be lost after power loss. All debugging work can be completed without the need for an external upper-level software.

6. Standard analog output

Each measurement channel is equipped with a isolated 4-20mA current output. The output signal is linearly corresponding to the measurement range. The signal isolation design can effectively resist industrial interference on-site and meet the usage requirements of remote data acquisition, trend curve recording, and centralized monitoring.

7. Programmable frequency response

The equipment supports two frequency response modes for on-site switching, which are suitable for different rotational equipment with different rotational speeds. The low-frequency mode is suitable for low-speed heavy-load units, and the high-frequency mode is suitable for high-speed turbine equipment. It can match the vibration frequency characteristics of different equipment.

IV. Working Principle

This equipment operates based on the mature non-contact eddy current measurement principle. The eddy current probe is connected to a high-frequency alternating current. When the probe is close to the metal shaft surface, the metal layer will induce eddy current. When the shaft system undergoes radial vibration, the gap between the probe and the shaft body will change dynamically, and the intensity of eddy current and the equivalent impedance of the probe itself will also change accordingly. The changed signal is transmitted through the high-frequency coaxial extension cable to the preamplifier, which completes signal amplification, shaping, temperature compensation, etc., and outputs a stable DC voltage signal sent to the 3300/16 monitoring module.

The internal circuit of the module splits the input signal into dynamic components and static components. The dynamic component is converted through calculation into the peak value of the shaft radial vibration, and the static component is converted into the average gap value between the probe and the shaft body. The system compares the measured values with the preset warning and danger thresholds. When the conditions are met, the corresponding relay is driven to act, and a switch quantity interlock signal is output. At the same time, the vibration value will be linearly converted into a 4-20mA standard current signal for external transmission. The two channels independently complete signal processing and logic judgment, combined with the circuit diagnosis function, to achieve reliable monitoring and protection throughout the process.

V. Main Technical Parameters

1. Input and compatibility system

The entire machine is equipped with two independent eddy current signal inputs, compatible with Benelli 3300XL series full-range eddy current probes, 330180 series preamplifiers, and 330130 series extension cables. The input impedance of the equipment is 10kΩ, which can perfectly match the output characteristics of the accompanying sensing equipment. The standard gap voltage working range is - 4VDC to - 20VDC, and the normal working point is - 12VDC.

2. Measurement performance parameters

The standard vibration measurement range of the equipment is 0 to 1 millimeter peak-to-peak, and it supports on-site small-scale range adjustment. Under normal temperature conditions, the full-scale measurement error of the entire machine does not exceed ±1%, and the single-point measurement accuracy is high. The overall resolution can reach 0.001 millimeters. The frequency response supports two selectable gears, namely 1 to 600 hertz and 4 to 4000 hertz, which can cover the vibration monitoring requirements of various rotating equipment from low speed to high speed. The shaft clearance measurement range matches the linear interval of the sensor and can be combined with the clearance voltage for status determination.

3. Output Parameters

The analog output is isolated 4-20mA direct current, with a maximum load of no more than 500Ω for a single channel output. The signal linearity is good. The relay output consists of 1 warning and 1 danger channel per channel. The contact withstand voltage is 250VAC, the rated current is 3A, and the normally open and normally closed modes can be programmed on-site.

4. Electrical Parameters

The equipment's working power supply is -24VDC, and the allowable voltage fluctuation range of the power supply is ±10% of the rated value. The normal operating power consumption of the entire machine is approximately 6W.

5. Environmental Parameters

The normal working environment temperature is 0℃ to 60℃, and the storage temperature range of the equipment is -40℃ to 85℃. The relative humidity of the working environment does not exceed 95%, and it is required that there be no condensation, corrosive gases, or strong dust inside the environment. The product has CE, UL, and CSA certifications, and the overall design complies with API 670 standard requirements.

6. Mechanical Parameters

It adopts a 19-inch standard rack structure, with a single-slot design, and the total weight of the machine is approximately 1.5 kilograms. The body adopts industrial-grade anti-interference and anti-vibration design, which can adapt to the complex electromagnetic and mechanical conditions of industrial sites.

Six. Installation and System Configuration

1. Rack Installation

The module adopts a plug-in structure and can be directly installed in the standard slot of the 3300 series dedicated system rack. Each slot occupies a small space, and the installation and disassembly operations are simple, with a neat layout, and are compatible with the standard cabinet installation specifications of the industrial control room.

2. Sensor Installation

Two electrical eddy current probes are arranged vertically in the XY direction outside the measured shaft. During installation, the initial gap of the probes is adjusted to the midpoint of the sensor's linear working range, corresponding to a standard clearance voltage of -12VDC, ensuring that the vibration and clearance measurements are always within the effective range. After the probe installation, make sure it is fixed properly to avoid displacement during operation.

3. On-site Wiring

The equipment wiring is divided into four categories: -24VDC power supply wiring, two sensor signal wiring, relay interlock wiring, and 4-20mA analog output wiring. During the wiring process, strictly distinguish the polarity and signal type of the lines according to the terminal markings on the body. After the wiring is completed, check the tightness of the lines to avoid false connections or incorrect connections.

4. Parameter Configuration

After the equipment is powered on, enter the configuration menu through the panel operation buttons, and complete the settings of vibration range, clearance monitoring parameters, warning and danger alarm thresholds, frequency response gear, corresponding relationship of analog output, relay contact mode, and fault alarm rules. After the parameter settings are completed, they will be automatically saved and will not be lost when the power is turned off. All debugging work can be completed on-site.

Seven. Typical Application Scenarios

In the power industry, it is mainly used for steam turbine generator sets, gas turbine generator sets, and large generators, to monitor the radial vibration of the shaft system and the probe clearance, protecting core components such as supporting bearings and shaft seals. In the petrochemical industry, it is widely used in centrifugal compressors, process turbines, and booster pump groups, preventing faults such as rotor and stator friction and blade damage caused by excessive vibration. In the metallurgical and general industrial fields, it is adapted to large exhaust fans, blowers, and high-speed pumps, to monitor the operating status of the shaft system and avoid bearing damage and shaft instability problems in advance. It can also be used for various small and medium-sized high-speed rotating machinery. During the start-up, load regulation, and full cycle of continuous operation of the unit, it provides dual protection against vibration and clearance.

VIII. Product Features and Advantages

First, the integration degree of functions is high. A single module can simultaneously achieve dual-channel radial vibration and static shaft clearance monitoring. It integrates multiple monitoring functions, reducing the number of on-site hardware, installation space, and wiring workload. Second, the operational reliability is strong. The dual-channel independent monitoring combined with the full-loop fault diagnosis function effectively avoids false alarms and false interlocks caused by sensor failures and abnormal lines, ensuring the stable operation of the protection system. Third, the measurement performance is excellent. It adopts mature eddy current non-contact measurement technology. The probe has no mechanical wear and is combined with a high-precision signal processing circuit. The measurement values are accurate, and the long-term drift is small. Fourth, the integration adaptability is good. The standard 4-20mA analog output and universal relay interface can seamlessly connect with mainstream industrial control systems. The system integration is simple and convenient. Fifth, the environmental adaptability is strong. The industrial-grade hardware design has a wide temperature and humidity working range. It has the ability to resist vibration and electromagnetic interference and can operate continuously in harsh industrial environments. Sixth, the operation and maintenance are convenient. It is equipped with a complete local operation interface. Without the need for professional upper-level equipment, it can complete status viewing, fault排查， and parameter modification. The modular structure also facilitates the rapid replacement of faulty modules， reducing equipment downtime.

IX. Supporting Components

This monitoring module must be paired with components of the same series to form a complete monitoring system. The core supporting components include the 3300XL series eddy current probes， which are selected according to the measured shaft diameter and installation space； the 330180 series preamplifiers， which are responsible for powering the probes and completing the pre-processing of the original signals； the 330130 series high-frequency coaxial extension cables， which are used to extend the signal transmission distance and are compatible with the layout distance between the equipment and the cabinet. In addition， it also needs to be paired with the 3300 series standard installation racks and the -24VDC dedicated power module to provide installation support and stable working power for the entire monitoring system.

I. Product Overview

The Bentley 3300/16 belongs to the 3300 series of rotating machinery protection system. It is a rack-mounted dual-channel radial vibration and shaft clearance comprehensive monitoring module. The current model 3300/16-14-01-01-00-00-00 is a standard customized configuration. The product strictly follows the API 670 industry standard. The equipment adopts a 19-inch standard cabinet single-slot modular design, which can be directly installed in the 3300 series system rack, and can be fully compatible with the same series eddy current probes, preamplifiers, extension cables, and power modules. This equipment is mainly used in steam turbines, gas turbines, centrifugal compressors, large generators, industrial fans, heavy-duty pump sets, and other key rotating machinery in the power, petrochemical, metallurgy, and other fields. It can simultaneously complete the real-time monitoring of two paths of shaft radial vibration and static shaft clearance, fault alarm, and safety interlock. It is the core equipment for protecting the bearing condition and shaft system operation status of rotating equipment.

II. Model Code Interpretation

3300/16 is the main product model, representing a dual-channel vibration and shaft clearance monitor. The suffix consists of seven two-digit segments, which define the hardware configuration, measurement range, output type, alarm logic, diagnostic function, hardware version, and certification configuration. The meanings of each segment of this model are as follows.

The first segment code 14 represents the channel function and measurement type configuration, which is suitable for two independent eddy current sensor inputs and supports the simultaneous collection of radial vibration peak-to-peak values and the static gap signal from the probe to the shaft body. It is a standard XY-axis vibration monitoring configuration.

The second segment code 01 represents the preset measurement range, corresponding to a vibration range of 0 to 1 mm peak-to-peak, suitable for small-sized rotating machinery with strict vibration amplitude requirements and high-speed shaft systems.

The third segment code 01 represents the analog output specification, using isolated 4-20mA direct current current output, which is an industrial standard signal and can be directly connected to DCS, PLC, SCADA, etc. industrial control systems.

The fourth segment code 00 represents the alarm logic configuration, using the factory default basic alarm logic, without additional customized channel voting, special interlock expansion functions.

The fifth segment code 00 represents the sensor circuit diagnostic configuration, enabling the standard full circuit diagnostic function, which can monitor the probe, extension cable, and preamplifier status.

The sixth segment code 00 represents the hardware version, being the original factory standard general hardware version, without special hardware modification and customization.

The seventh segment code 00 represents additional functions and certifications, equipped with CE, UL, CSA international universal certifications, without additional additional functions and special industry customization requirements.

III. Core Functions

1. Dual-channel Comprehensive Monitoring

The equipment has two independent measurement channels that can be externally connected to two sets of vertically arranged eddy current probes to simultaneously complete the synchronous collection and calculation of two paths of axial vibration and static shaft clearance. The two channels do not interfere with each other, and a single channel failure will not affect the normal operation of the other channel. The dual-channel monitoring architecture enhances the stability of the entire system operation.

2. Equipment Fault Early Warning

Continuous tracking of the axial radial vibration amplitude and the static gap changes of the shaft, which can effectively identify common fault hazards such as rotor imbalance, shaft misalignment, bearing wear, oil film instability, shaft displacement deviation, and probe installation abnormalities, and issue early warning signals to avoid vibration over-limit, shaft friction, bearing burnout, etc., ensuring the safe and stable operation of the unit.

3. Graded Alarm and Interlock Protection Each channel is independently configured with one warning relay and one danger relay. The vibration threshold and gap threshold can be independently set through local buttons. The rated parameters of the relay contacts are 250VAC and 3A. The contact mode can be set as normally open or normally closed. The equipment can be configured with hierarchical alarms, unit interlocks, and emergency shutdown logic according to the on-site process requirements.

4. Self-diagnosis of sensor circuit faults

The device is equipped with a complete circuit monitoring program that can detect the entire sensing circuit composed of the probe, extension cable, and preamplifier in real time. Once problems such as open circuit, short circuit, signal beyond the measurement range, or abnormal power supply occur, the equipment will immediately trigger a sensor fault alarm and mark the abnormal channels to prevent false alarms or interlocks caused by abnormal signals.

5. Local display and parameter configuration

The body is equipped with an LED digital display and physical operation buttons. Maintenance personnel can directly view real-time vibration values, static gap voltage, current alarm status, and channel operation status on-site. The equipment supports local configuration of all parameters such as range, alarm threshold, analog output correspondence, frequency response, and relay action mode. All settings parameters are automatically saved, and the data will not be lost after power loss. All debugging work can be completed without the need for an external upper-level software.

6. Standard analog output

Each measurement channel is equipped with a isolated 4-20mA current output. The output signal is linearly corresponding to the measurement range. The signal isolation design can effectively resist industrial interference on-site and meet the usage requirements of remote data acquisition, trend curve recording, and centralized monitoring.

7. Programmable frequency response

The equipment supports two frequency response modes for on-site switching, which are suitable for different rotational equipment with different rotational speeds. The low-frequency mode is suitable for low-speed heavy-load units, and the high-frequency mode is suitable for high-speed turbine equipment. It can match the vibration frequency characteristics of different equipment.

IV. Working Principle

This equipment operates based on the mature non-contact eddy current measurement principle. The eddy current probe is connected to a high-frequency alternating current. When the probe is close to the metal shaft surface, the metal layer will induce eddy current. When the shaft system undergoes radial vibration, the gap between the probe and the shaft body will change dynamically, and the intensity of eddy current and the equivalent impedance of the probe itself will also change accordingly. The changed signal is transmitted through the high-frequency coaxial extension cable to the preamplifier, which completes signal amplification, shaping, temperature compensation, etc., and outputs a stable DC voltage signal sent to the 3300/16 monitoring module.

The internal circuit of the module splits the input signal into dynamic components and static components. The dynamic component is converted through calculation into the peak value of the shaft radial vibration, and the static component is converted into the average gap value between the probe and the shaft body. The system compares the measured values with the preset warning and danger thresholds. When the conditions are met, the corresponding relay is driven to act, and a switch quantity interlock signal is output. At the same time, the vibration value will be linearly converted into a 4-20mA standard current signal for external transmission. The two channels independently complete signal processing and logic judgment, combined with the circuit diagnosis function, to achieve reliable monitoring and protection throughout the process.

V. Main Technical Parameters

1. Input and compatibility system

The entire machine is equipped with two independent eddy current signal inputs, compatible with Benelli 3300XL series full-range eddy current probes, 330180 series preamplifiers, and 330130 series extension cables. The input impedance of the equipment is 10kΩ, which can perfectly match the output characteristics of the accompanying sensing equipment. The standard gap voltage working range is - 4VDC to - 20VDC, and the normal working point is - 12VDC.

2. Measurement performance parameters

The standard vibration measurement range of the equipment is 0 to 1 millimeter peak-to-peak, and it supports on-site small-scale range adjustment. Under normal temperature conditions, the full-scale measurement error of the entire machine does not exceed ±1%, and the single-point measurement accuracy is high. The overall resolution can reach 0.001 millimeters. The frequency response supports two selectable gears, namely 1 to 600 hertz and 4 to 4000 hertz, which can cover the vibration monitoring requirements of various rotating equipment from low speed to high speed. The shaft clearance measurement range matches the linear interval of the sensor and can be combined with the clearance voltage for status determination.

3. Output Parameters

The analog output is isolated 4-20mA direct current, with a maximum load of no more than 500Ω for a single channel output. The signal linearity is good. The relay output consists of 1 warning and 1 danger channel per channel. The contact withstand voltage is 250VAC, the rated current is 3A, and the normally open and normally closed modes can be programmed on-site.

4. Electrical Parameters

The equipment's working power supply is -24VDC, and the allowable voltage fluctuation range of the power supply is ±10% of the rated value. The normal operating power consumption of the entire machine is approximately 6W.

5. Environmental Parameters

The normal working environment temperature is 0℃ to 60℃, and the storage temperature range of the equipment is -40℃ to 85℃. The relative humidity of the working environment does not exceed 95%, and it is required that there be no condensation, corrosive gases, or strong dust inside the environment. The product has CE, UL, and CSA certifications, and the overall design complies with API 670 standard requirements.

6. Mechanical Parameters

It adopts a 19-inch standard rack structure, with a single-slot design, and the total weight of the machine is approximately 1.5 kilograms. The body adopts industrial-grade anti-interference and anti-vibration design, which can adapt to the complex electromagnetic and mechanical conditions of industrial sites.

Six. Installation and System Configuration

1. Rack Installation

The module adopts a plug-in structure and can be directly installed in the standard slot of the 3300 series dedicated system rack. Each slot occupies a small space, and the installation and disassembly operations are simple, with a neat layout, and are compatible with the standard cabinet installation specifications of the industrial control room.

2. Sensor Installation

Two electrical eddy current probes are arranged vertically in the XY direction outside the measured shaft. During installation, the initial gap of the probes is adjusted to the midpoint of the sensor's linear working range, corresponding to a standard clearance voltage of -12VDC, ensuring that the vibration and clearance measurements are always within the effective range. After the probe installation, make sure it is fixed properly to avoid displacement during operation.

3. On-site Wiring

The equipment wiring is divided into four categories: -24VDC power supply wiring, two sensor signal wiring, relay interlock wiring, and 4-20mA analog output wiring. During the wiring process, strictly distinguish the polarity and signal type of the lines according to the terminal markings on the body. After the wiring is completed, check the tightness of the lines to avoid false connections or incorrect connections.

4. Parameter Configuration

After the equipment is powered on, enter the configuration menu through the panel operation buttons, and complete the settings of vibration range, clearance monitoring parameters, warning and danger alarm thresholds, frequency response gear, corresponding relationship of analog output, relay contact mode, and fault alarm rules. After the parameter settings are completed, they will be automatically saved and will not be lost when the power is turned off. All debugging work can be completed on-site.

Seven. Typical Application Scenarios

In the power industry, it is mainly used for steam turbine generator sets, gas turbine generator sets, and large generators, to monitor the radial vibration of the shaft system and the probe clearance, protecting core components such as supporting bearings and shaft seals. In the petrochemical industry, it is widely used in centrifugal compressors, process turbines, and booster pump groups, preventing faults such as rotor and stator friction and blade damage caused by excessive vibration. In the metallurgical and general industrial fields, it is adapted to large exhaust fans, blowers, and high-speed pumps, to monitor the operating status of the shaft system and avoid bearing damage and shaft instability problems in advance. It can also be used for various small and medium-sized high-speed rotating machinery. During the start-up, load regulation, and full cycle of continuous operation of the unit, it provides dual protection against vibration and clearance.

VIII. Product Features and Advantages

First, the integration degree of functions is high. A single module can simultaneously achieve dual-channel radial vibration and static shaft clearance monitoring. It integrates multiple monitoring functions, reducing the number of on-site hardware, installation space, and wiring workload. Second, the operational reliability is strong. The dual-channel independent monitoring combined with the full-loop fault diagnosis function effectively avoids false alarms and false interlocks caused by sensor failures and abnormal lines, ensuring the stable operation of the protection system. Third, the measurement performance is excellent. It adopts mature eddy current non-contact measurement technology. The probe has no mechanical wear and is combined with a high-precision signal processing circuit. The measurement values are accurate, and the long-term drift is small. Fourth, the integration adaptability is good. The standard 4-20mA analog output and universal relay interface can seamlessly connect with mainstream industrial control systems. The system integration is simple and convenient. Fifth, the environmental adaptability is strong. The industrial-grade hardware design has a wide temperature and humidity working range. It has the ability to resist vibration and electromagnetic interference and can operate continuously in harsh industrial environments. Sixth, the operation and maintenance are convenient. It is equipped with a complete local operation interface. Without the need for professional upper-level equipment, it can complete status viewing, fault排查， and parameter modification. The modular structure also facilitates the rapid replacement of faulty modules， reducing equipment downtime.

IX. Supporting Components

This monitoring module must be paired with components of the same series to form a complete monitoring system. The core supporting components include the 3300XL series eddy current probes， which are selected according to the measured shaft diameter and installation space； the 330180 series preamplifiers， which are responsible for powering the probes and completing the pre-processing of the original signals； the 330130 series high-frequency coaxial extension cables， which are used to extend the signal transmission distance and are compatible with the layout distance between the equipment and the cabinet. In addition， it also needs to be paired with the 3300 series standard installation racks and the -24VDC dedicated power module to provide installation support and stable working power for the entire monitoring system.