Category: Instrumentation

——Practical Analysis Based on HandleException / Default Policy Software Errors

Abstract
The Malvern Mastersizer series of laser particle size analyzers are widely used in laboratories and industrial quality inspection fields. However, abnormalities during software startup are not uncommon. This paper provides an in-depth analysis of the typical error message “An unexpected exception occurred while calling HandleException with policy ‘Default Policy'” that occurs during the startup process. It dissects the issue from the perspectives of the software framework, runtime library dependencies, instrument hardware communication, Aero dry dispersion module, and the Windows system level, offering a complete diagnostic logic, troubleshooting process, and solution ideas for third-party maintenance engineers and equipment managers.

I. Introduction: Why is Malvern Mastersizer prone to startup abnormalities?
The Mastersizer series (including models 2000, 3000, and 3000E) are high-precision particle size testing devices that involve multiple modules such as optical measurement modules, laser optical path systems, expansion units, high-speed data acquisition cards, communication links, and PC software environments. An abnormality in any of these modules can lead to software startup failure. In particular, the Mastersizer 3000 software adopts the Microsoft .NET + Enterprise Library exception management framework, resulting in a complex exception structure that is prone to “HandleException” and “Default Policy” related errors.

II. Reproducing the Fault Phenomenon: What does the error message indicate?
When users start the software, they may see a pop-up window labeled “Application Error” with the message “An unexpected exception occurred while calling HandleException with policy ‘Default Policy’. Please check the event log for details about the exception.” This indicates the following:

• An exception has been captured internally by the software, such as module initialization failure, configuration file reading failure, or device non-response.
• The “Default Policy” that captures the exception has itself encountered an error. The software uses the Microsoft Enterprise Library Exception Handling Block, and when the default policy fails to execute, the software cannot continue to start.
• Such errors do not necessarily directly prove instrument damage; they are more likely to reflect issues such as driver abnormalities, missing software dependencies, or disconnected communication links.

III. Analysis of the Mastersizer Software Startup Process: Understanding the root causes of faults from the source

1. Software loading of its dependent DLLs
   This includes the .NET Framework, VC++ Runtime, Malvern core module DLLs, and Enterprise Library configuration files, among others. If any DLLs are missing or corrupted, startup abnormalities will occur.
2. Software reading of configuration files
   This involves instrument model information, recently used module configurations, communication ports, laser initialization parameters, and dispersion module configurations. Reading failures will trigger exceptions.
3. Instrument communication initialization
   The communication link for the Mastersizer 3000 may be USB, fiber optic, or RS-232. If the software does not receive a response from the instrument during the initialization stage, an exception will be thrown, especially when there are abnormalities in the Aero dry dispersion module.
4. Optical system initialization
   Failure to turn on the laser drive, non-response from the optical path unit, or no return from the ADC data acquisition card can also lead to software startup failure.
5. Software UI loading
   This stage is unlikely to cause HandleException unless there is damage to system fonts or abnormalities in Windows graphical components.

IV. Typical root causes that may lead to HandleException (ranked by probability)

1. Instrument communication failure (highest probability)
   Examples include loose or damaged USB cables, use of incompatible USB-HUBs, uninstalled or corrupted USB drivers, and Aero modules that are not powered on or have internal communication board failures.
2. Corrupted or missing .NET Framework (very common)
   The software relies on .NET 3.5 and .NET 4.0/4.5. Windows updates, viruses, or incorrect software uninstallation can damage these components.
3. Missing VC++ runtime libraries (often overlooked but very critical)
   Malvern uses a large number of C++ modules internally, and missing VC++ Runtime libraries will prevent the program from loading.
4. Corrupted local configuration files of Malvern software
   Corruption or formatting errors in files such as software.config, exception.config, and user.config can prevent the Enterprise Library from reading them, triggering Default Policy errors.
5. Windows permission issues
   Examples include the program being unable to write to ProgramData, the software not having administrator privileges, or company IT-installed antivirus systems blocking access to key files.
6. Host and dispersion hardware issues
   These include damage to the Aero fan module, inability of the control board to power on, abnormal sensor output, or interrupted data links.

V. Complete on-site troubleshooting process (standard operating procedure for engineers)
Step 1: Confirm physical connections and power-on status
Check all USB/fiber optic communication cables, unplug and replug them, avoid using USB-HUBs, confirm that both the Mastersizer host and Aero are powered on, and observe whether the LED indicators are normal.
Step 2: Restart the device and computer
The recommended sequence is to close the software, turn off the instrument, restart the computer, turn on the instrument, and then open the software. This is the reset method recommended by Malvern.
Step 3: Check the Windows event log (critical)
Navigate to “Event Viewer → Windows Logs → Application” and search for relevant logs such as Malvern, Mastersizer, .NET Runtime, and Application Error to obtain detailed exception sources.
Step 4: Repair system runtime libraries
Install .NET Framework 3.5, .NET Framework 4.0/4.5, and VC++ 2005/2008/2010/2012/2013 runtime libraries. You can use the Microsoft .NET Repair Tool and the Visual C++ Redistributable Package collection to perform repairs.
Step 5: Reset or delete software configuration files (commonly effective)
Delete the configuration files in the C:\Users\username\AppData\Local\Malvern\ and C:\ProgramData\Malvern\ directories. The software will automatically regenerate them.
Step 6: Reinstall the software (ultimate solution)
This is suitable for situations such as software corruption, abnormal configuration files, missing DLLs, or interference from enterprise antivirus software. A complete reinstallation will almost restore normal operation.

VI. Special case: Abnormalities caused by the Aero dry dispersion module
In the Mastersizer + Aero dry dispersion module combination system, the Aero contains components such as a motor drive, differential pressure sensor, control CPU board, and speed feedback system. If the Aero’s internal hardware is damaged, error messages such as “Unexpected exception” and “Failed to initialize module: Aero” will appear during the software initialization stage. If you observe no indicator lights when the Aero is powered on, no startup action of the suction fan, abnormal fan current, or non-operation of the internal fan on-site, the problem may be concentrated on damage to the Aero control board or fan drive board.

VII. Best advice for engineers

• Confirm communication lines and device power-on status: Re-plug the communication lines and avoid using USB-HUBs.
• Restart the device and computer: Follow the correct restart sequence.
• Check the event log: Obtain detailed exception information.
• Repair the .NET Framework and VC++ Runtime: Ensure that software dependencies are complete.
• Exclude equipment hardware abnormalities (especially Aero): Focus on the fan, control board, and power module.
• Reinstall the software if necessary: Use this as the final solution.

VIII. Conclusion: The essence and solution direction of Mastersizer startup abnormalities
The error “An unexpected exception occurred while calling HandleException with policy ‘Default Policy'” analyzed in this paper is, from a software structure perspective, a secondary exception caused by the failure of the software’s exception handling mechanism. However, the root causes often lie in system runtime libraries, drivers, configuration files, communication links, or abnormal initialization of instrument modules (especially Aero). Through a systematic diagnostic process, almost 100% of the problems can be located.

IX. Appendix: On-site troubleshooting checklist for engineers (printable)
✔ Communication check

• Loose USB/fiber optic cables
• Whether the HUB has been removed
• Whether the instrument is properly powered on
  ✔ Software environment
• .NET Framework 3.5/4.x
• Integrity of VC++ Runtime
• Whether the software has been blocked by enterprise antivirus software
  ✔ Windows system
• Permissions
• Event Viewer
• Whether there are conflicting drivers
  ✔ Instrument hardware
• Aero fan
• Control board
• Internal sensors
• Host power module
  ✔ Software repair
• Delete configuration files
• Reinstall the software

X. Overall Summary
By technically dissecting the startup process of the Malvern Mastersizer particle size analyzer and analyzing the root causes of HandleException / Default Policy errors, it can be concluded that such faults are the result of a comprehensive failure in the coordination of the software, system, drivers, and instrument initialization processes. As long as engineers master the troubleshooting logic proposed in this paper, they can quickly locate and accurately repair most on-site abnormalities.

Introduction

The Cydem VT Automated Cell Culture System, as a vital tool in modern biotechnology, significantly enhances the efficiency and stability of cell culture through its highly integrated automation design. Based on the core content of the system manual and combined with operational logic and practical tips, this guide provides researchers with a comprehensive reference for use. Covering the entire process from system overview to advanced applications, including installation, operation, maintenance, and troubleshooting, it aims to help users fully master the operation essence of this advanced equipment. The following content is strictly written in accordance with the manual specifications to ensure practicality and accuracy.

Chapter 1: System Overview and Core Advantages

1.1 System Definition and Application Scope

The Cydem VT system is a modular, fully automated cell culture platform that integrates four core modules: temperature control, gas regulation, liquid handling, and real-time monitoring. Designed to replace traditional manual operations, it is suitable for scenarios requiring high repeatability and sterile conditions, such as pharmaceutical research and development, oncology research, and stem cell culture. The system enables human-machine interaction through a touchscreen interface and remote control software, supporting multi-task parallel processing.

1.2 Technical Features Analysis

• Precise Environmental Control: The incubator maintains a temperature fluctuation range of ≤ ±0.2°C, CO₂ concentration control accuracy of ±0.1%, and humidity above 95%, ensuring a stable environment for cell growth.
• Automated Liquid Handling: Equipped with a built-in multi-channel pipetting arm, it supports liquid transfer from 1 μL to 50 mL with an error rate below 2%.
• Contamination Prevention Mechanism: It employs a dual safeguard of HEPA filtration and UV sterilization, with key pipelines equipped with check valves to prevent cross-contamination.
• Data Traceability Function: All operational parameters and cell images are automatically stored and can be exported in CSV or PDF formats.

Chapter 2: Hardware Installation and Initial Configuration

2.1 Site Preparation Requirements

The system should be placed on a level and stable laboratory bench with a surrounding clearance of at least 50 cm for heat dissipation. The power supply requirement is 220 V ± 10%/50 Hz, and an independent grounding line must be connected. The ambient temperature is recommended to be maintained between 18°C and 25°C, avoiding direct sunlight or direct alignment with ventilation openings.

2.2 Core Component Installation Process

• Main Unit Positioning: Remove the transportation fixing bolts and adjust the feet until the level indicator shows green.
• Culture Module Assembly: Insert the culture dish holder into the slide rail until it locks into place with a click. Handle glass components gently.
• Liquid Pathway Connection:
  • Connect the culture medium bottle and waste liquid bottle to the color-coded interfaces respectively (blue for air intake, red for liquid pathway).
  • Perform pipeline priming: Select “Liquid Pathway Cleaning” in the software interface until there are no air bubbles in the pipeline.
• Gas Source Configuration: Connect the CO₂ cylinder to the back interface of the system through a pressure reducer, with an initial pressure setting recommended at 0.1–0.15 MPa.

2.3 First-time Startup and Calibration

After powering on, the system performs a self-check (approximately 5 minutes), and the touchscreen displays the initialization interface. Follow the prompts to complete:

• Sensor Calibration: Including pH electrode calibration (using standard buffer solutions) and O₂ probe calibration (zeroing in air).
• Mechanical Arm Origin Correction: The pipetting arm automatically moves to the preset position and records the coordinates.
• User Permission Settings: Assign administrator and operator accounts, set passwords, and define operational scope restrictions.

Chapter 3: Full Process Analysis of Daily Operations

3.1 Culture Initiation Phase

• Step 1 – Program Creation: Create a new task in the “Protocol Editor,” with key parameters including:
  • Culture type (adherent/suspension cells)
  • Liquid exchange frequency (e.g., every 48 hours)
  • Termination conditions (OD value ≥ 0.8 or time threshold)
• Step 2 – Sample Loading:
  • Use sterile forceps to place the culture dish on the loading platform and scan the barcode to associate sample information.
  • For adherent cells, allow them to settle for 10 minutes; for suspension cells, directly initiate the mixing program.
• Step 3 – Environmental Parameter Setting: Select a preset mode according to the cell type (e.g., the HEK-293 mode automatically sets to 37°C/5% CO₂), or manually input:

Temperature: 37.0°C  
CO₂: 5.0%  
O₂: Set as required (conventionally 20%)  
Humidity: ≥ 95%

3.2 Monitoring During Operation

• Real-time Data Viewing: Switch to the “Monitoring” tab on the main interface to view temperature fluctuation curves and pH trend graphs.
• Abnormal Alarm Handling: When a “Liquid Insufficient” warning appears, pause the task → replace the culture medium bottle → resume operation.
• Intermediate Intervention Operations: Wear sterile gloves, pause the mechanical arm using the emergency stop button, and quickly complete sampling or liquid supplementation.

3.3 Culture Termination and Sample Collection

Select the target experiment from the task list and click “Terminate.” The system automatically performs:

• The pipetting arm aspirates and discards the waste liquid.
• It injects 0.25% trypsin (for adherent cells).
• The low-temperature preservation module is lowered to 4°C.
  After removing the samples, immediately execute the “Quick Clean” program (taking approximately 15 minutes).

Chapter 4: Maintenance and Upkeep Specifications

4.1 Daily Maintenance Checklist

• Check the waste liquid bottle level (empty if it exceeds 80%).
• Wipe the touchscreen and exterior surfaces with 70% ethanol.
• Confirm the remaining pressure in the CO₂ cylinder (replace if it is below 0.05 MPa).

4.2 Weekly In-depth Maintenance

• Pipeline Disinfection: Run the “Sterilization” program and circulate 0.1 M NaOH solution for 30 minutes.
• Mechanical Arm Lubrication: Apply specialized silicone grease to the XYZ-axis guide rails (never use Vaseline).
• Sensor Calibration: Soak the pH electrode in 3 M KCl storage solution and perform air calibration for the O₂ sensor.

4.3 Monthly Inspection Items

• Replace the HEPA filter (Part Number: CYD-FIL-01).
• Check the aging of the sealing rings of the pipette tips.
• Back up system logs and user data to an external storage device.

Chapter 5: Fault Diagnosis and Emergency Response

5.1 Common Alarm Handling Solutions

Alarm Code	Meaning	Handling Action
E-102	Temperature Exceeding Limit	Check the incubator door seal and reset the heating module.
E-205	Liquid Pathway Blockage	Execute the pipeline backflush program and replace the 0.22 μm filter.
E-311	Communication Timeout	Restart the control computer and check the network cable connection.

5.2 Emergency Situation Response

• Power Interruption: The system automatically activates the backup battery to maintain the operation of key sensors. Power must be restored within 2 hours.
• Contamination Incident: Immediately initiate “Emergency Sterilization” (UV + 75% ethanol spray). Contaminated culture dishes must be autoclaved before disposal.
• Mechanical Arm Collision: Enter “Maintenance Mode” to manually adjust the arm position and calibrate the track encoder.

Chapter 6: Advanced Functions and Application Expansion

6.1 Multi-task Parallel Strategy

Through the “Batch Scheduler” function, up to 6 independent experiments can be managed simultaneously. It is recommended to group them according to the following principles:

• Arrange the same type of cells in the same batch.
• Prioritize high-frequency detection tasks for daytime periods.
• Set resource conflict warnings (e.g., detection of overlapping pipette usage).

6.2 Data In-depth Analysis Techniques

• Growth Curve Fitting: After exporting OD data, use the built-in Gompertz model in the system to calculate the doubling time.
• Morphological Analysis: Combine with the microscopic imaging module to quantify cell aggregation degree through image segmentation algorithms.
• Custom Report Template: In the “Report Generator,” drag and drop fields to generate experimental reports compliant with GLP specifications.

6.3 Remote Control Configuration

After connecting to the laboratory local area network via Ethernet:

• Enable “Remote Access” permissions in the administrator account.
• Use the official app (Cydem Controller) to scan the device QR code for binding.
• Set operation delay compensation (recommended ≤ 200 ms within the local area network).

Conclusion

The value of the Cydem VT system lies not only in replacing manual operations with automation but also in ensuring the repeatability and traceability of experimental data through standardized processes. It is recommended that users establish a complete set of SOP documentation, participate in technical training organized by the manufacturer at least once a year, and stay updated on firmware update announcements to obtain functional optimizations. This guide covers the core operational scenarios of the system, and parameters should be flexibly adjusted according to specific experimental needs in actual use to maximize equipment performance.

Abstract

Laser particle size analyzers are widely used in fields such as materials science, powder technology, biopharmaceuticals, and mineral processing. Their measurement accuracy and repeatability are key indicators for evaluating equipment performance. The Anton Paar PSA 1090 LD, as a high-precision wet laser particle size analyzer, may encounter typical abnormalities such as “slow drainage, low flow rate, system blockage, poor measurement repeatability, and large particle size deviation” during long-term use. Based on actual fault cases of a user’s equipment, this study conducts a systematic analysis from multiple dimensions including the light path, flow path, circulation pump, dispersion cell, and drainage channel, and proposes technical cause determination methods and engineering maintenance steps. This article aims to provide a complete set of fault diagnosis methods and scientific maintenance paths for third-party laboratories, after-sales engineers, and equipment users, helping to improve instrument reliability and service life.

1. Introduction

Laser particle size analyzers play an irreplaceable role in the field of powder and particle material characterization. With the rapid development of materials science and nanotechnology, the requirements for the accuracy, stability, and repeatability of particle size testing continue to increase. The Anton Paar PSA 1090 LD, as an internationally recognized laser particle size analyzer, has core advantages such as high light path stability, good dispersion effect, and high system automation. However, even high-end equipment may still encounter typical problems such as “slow drainage, blockage, poor repeatability, and large particle size deviation” during long-term operation or improper maintenance.

Based on real-world usage cases, this article, from the perspective of third-party laboratory engineers, systematically analyzes the root causes of such faults and provides immediately implementable diagnostic methods, aiming to provide high-value references for relevant practitioners.

2. Working Principle and System Composition of the PSA 1090 LD

To understand why the equipment exhibits abnormalities, it is necessary to first understand its internal structure and operating mechanism.

2.1 Introduction to the Wet Dispersion System

The PSA 1090 LD uses a wet dispersion method, where the liquid is driven by a circulation pump to form a continuous flow between the sample cell and the water tank. The water flow undertakes three tasks:

• Transporting sample particles
• Ensuring uniform dispersion of particles
• Providing a stable light path environment

The stability of the flow rate determines whether the sample can uniformly pass through the light beam and whether the measurement can be precise.

2.2 Structure of the Light Path System

The laser is emitted from the transmitting end, passes through the sample in the sample cell, and the scattered light is collected by the detector. If the light path is affected, it will lead to significant data deviations.

Light path window contamination may cause:

• Unstable scattered light intensity
• Increased data noise
• Abnormal oscillation of the particle size curve

This is an important factor contributing to measurement deviations.

2.3 Importance of the Circulation System and Fluid Dynamics

The circulation system consists of:

• Suction hose
• Circulation pump
• Flow cell (sample cell)
• Drainage channel

An increase in resistance at any position will lead to:

• Decreased water flow
• Inability to discharge bubbles
• Accumulation of particles in the cell
• Unstable test curves

Actual cases show that fluid dynamic problems are the main source of abnormalities in the PSA series.

3. Fault Manifestations and Initial Symptoms

According to feedback from the user’s site and video footage, the equipment exhibited typical system fault characteristics.

3.1 Slow Drainage and Insufficient Flow Rate

This is the most intuitive abnormal phenomenon. A normal device should be able to complete drainage quickly, but in this case:

• The drainage speed is significantly reduced
• The water flow is interrupted or intermittent
• There is a noticeable sense of resistance

This indicates partial blockage within the circulation system.

3.2 Particle Deposition and Flocculation in the Sample Cell

From the photos of the sample cell window, it can be seen that:

• There is a large amount of sediment at the bottom
• There are flocculent impurities
• The light path channel is not clean

This directly affects measurement accuracy.

3.3 Huge Deviations in Multiple Measurement Results

For example:

• D50 changes from 0.8 µm to 58 µm (a jump of 70 times)
• The shapes of the three curves are completely different

This phenomenon is definitely not due to sample problems but rather:

• Uneven flow rate
• Incomplete dispersion of aggregates
• Laser signal fluctuations

These cause systematic deviations.

3.4 Bubble Retention and Discontinuous Fluid Flow

The video shows the presence of:

• A large number of bubbles in the liquid
• Interruptions and jumps in the liquid flow
• Inability of the water body to continuously flow through the sample cell

This directly leads to a sharp increase in optical signal noise.

4. Systematic Analysis of Fault Causes

Based on the fault manifestations, the main abnormal sources involved in this case are as follows.

4.1 Blockage in the Dispersion Cell and Flow Cell

The bottom of the sample cell and the drainage outlet are the most prone to blockage. Long-term accumulation of:

• Microparticles
• Scale
• Sediment
• Organic film

will narrow the fluid channel.

Results:

• Insufficient flow rate
• Discontinuous signals
• Jittering of the particle size curve

4.2 Blockage in the Drainage Channel (Core Cause in This Case)

The drainage channel is narrow, and even a small amount of sediment can significantly affect the flow rate. In this case, the obvious slowdown in drainage indicates severe blockage in the channel.

4.3 Insufficient Suction or Excessive Load of the Circulation Pump

The circulation pump is not damaged but rather:

• The resistance in the pathway has increased
• It is difficult to form sufficient flow
• The pump idles, is sluggish, or has fluctuating water output

This leads to abnormalities in the entire system.

4.4 Aging of the Water Inlet Hose and Formation of Biofilm

The hose in this case has shown:

• Yellowing
• Rough inner walls
• Increased flow resistance

Biofilm or sediment reduces the water absorption efficiency.

4.5 Light Path Window Contamination and Optical Signal Attenuation

Deposits on the window will:

• Change the incident light intensity
• Cause abnormal scattering
• Trigger abnormal peaks in particle size
• Deform the distribution curve

This is significantly present in this case.

4.6 Software Parameter Factors

Although parameters such as refractive index and dispersion mode can also affect the results, they will not cause mechanical problems such as “slow drainage” and can be excluded.

5. Engineering Diagnostic Steps

The following diagnostic process can be used by third-party laboratories to judge the performance of the PSA series wet systems.

5.1 Flow Observation Method

Normal: Continuous flow
Abnormal: Flow interruption, slowness, repeated appearance of bubbles
In this case, the flow rate is severely insufficient.

5.2 Blank Baseline Stability Judgment

A stable signal during blank testing indicates a normal light path; fluctuations suggest light path or fluid abnormalities.
In this case, the baseline noise is significantly increased.

5.3 Evaluation of Ultrasonic Dispersion Effectiveness

If particles still aggregate after ultrasonic activation, it indicates:

• Insufficient flow rate
• Inability to carry away aggregates

rather than a fault in the ultrasonic device itself.

5.4 Inspection of the Optical Window of the Sample Cell

The presence of:

• Mildew spots
• Scale
• Contamination points

may lead to unstable data.

5.5 Drainage Speed Test

The slower the drainage speed, the more it indicates:

• Blockage in the flow channel
• Adherents on the pipe walls
• Excessive system resistance

In this case, the drainage speed has significantly decreased.

5.6 Judgment of Circulation Pump Performance

If the pump can operate normally but the flow rate is insufficient, it is mostly due to excessive resistance, and the pump may not necessarily be damaged.

6. System Maintenance and Recovery Plan (Engineer Level)

The following are the most effective maintenance steps for the PSA series.

6.1 Cleaning the Flow Path: Circulation with 1% NaOH Solution

Steps:

• Add 1% NaOH solution to the water tank
• Operate at the maximum flow rate for 10–15 minutes
• Then rinse with a large amount of pure water for 10 minutes
• If there is an ultrasonic function, activate it for collaborative cleaning

Functions:

• Dissolve sediment
• Remove biofilm
• Clean the flow channel

6.2 Reverse Flushing of the Sample Cell (Key Step)

Using a 50–100 mL syringe:

• Unplug the drainage hose
• Aim the syringe at the drainage outlet
• Inject water backward into the sample cell

It is normal to flush out black or yellow sediment. This is the most effective unclogging method for the PSA series.

6.3 Replacement of the Water Inlet Hose and Drainage Pipe

Aging hoses cause poor water absorption. In this case, the pipes are obviously aged and need to be completely replaced with new ones.

6.4 Cleaning Method for the Light Path Window

Use:

• 70–99% IPA
• Fiber-free cotton swabs

Gently wipe the contaminated areas and avoid scratching with hard objects.

6.5 Standard Process for Eliminating Bubbles

• Operate at the maximum circulation
• Tilt the instrument by 20–30 degrees
• Discharge the liquid multiple times
• Continuously observe the changes in bubbles inside the sample cell

6.6 Final Calibration and Repeatability Verification

Test:

• Three repeatability curves
• Stability of D10, D50, and D90
• Baseline noise level

After recovery, the curves should have a high degree of overlap.

7. Case Study: Correspondence between Abnormal Data and Real Causes

In this case, typical “data distortion caused by unstable system flow rate” is observed.

7.1 Abnormal Shoulder Peaks in the Particle Size Distribution Curve

Shoulder peaks indicate that the particles are not uniformly dispersed, which is a false peak caused by unstable flow.

7.2 Direct Correlation between D50 Jumps and Flow Rate Problems

Insufficient flow rate will lead to:

• Deposition of large particles, resulting in false large particle peaks
• Uneven concentration, causing jumps

This is completely consistent with this case.

7.3 Reasons for Different Shapes of Three Measurement Curves

• Interruption of water flow
• Bubbles passing through the light path
• Fluctuations in sample concentration

Not due to the sample itself.

8. Preventive Maintenance Strategies and Recommendations

To prevent similar faults from occurring again, the following maintenance system should be established:

8.1 Lifespan Management of Pipelines

It is recommended to replace hoses every 6–12 months.

8.2 Flow Path Cleaning Plan

Recommendations:

• Clean with pure water once a week
• Perform NaOH circulation once a month
• Conduct reverse flushing once a quarter

8.3 Light Path Maintenance Cycle

Check the light path window every 1–2 months and immediately remove any scale if present.

8.4 Water Quality and Environment

Must use:

• Deionized water (electrical conductivity < 10 μS/cm)
• Clean sample cups
• Avoid dust entering the water tank

9. Conclusion

This case fully demonstrates that when the Anton Paar PSA 1090 LD exhibits faults such as “slow drainage, blockage, and large particle size deviation,” the root causes are mostly a combination of fluid dynamic abnormalities, light path contamination, and aging pipelines. Through systematic diagnosis and engineering maintenance, the equipment performance can be fully restored.

Key insights include:

• The flow rate is the primary factor affecting the measurement accuracy of wet methods
• The drainage channel and sample cell are the most important cleaning points
• Light path window contamination can sharply reduce measurement repeatability
• Pipeline aging can lead to potential resistance problems
• Ultrasonication and flow rate must work in tandem to ensure sufficient dispersion

For third-party laboratories and engineers, establishing standardized maintenance procedures is a necessary measure to ensure the long-term stable operation of instruments.

— A Focus on “END” Faults and TRIP Light Illumination

Table of Contents

1. Introduction
2. Fundamentals of Inverters 2.1 How Inverters Work 2.2 Technical Specifications of Anruiji E6 Series Inverters 2.3 Core Functions and Applications
3. Basic Fault Diagnosis Process 3.1 Classification of Fault Phenomena 3.2 Steps for Fault Diagnosis
4. In-Depth Analysis of “END” Faults and TRIP Light Illumination 4.1 Definition and Manifestation of Faults 4.2 Possible Causes of Faults 4.3 Viewing and Interpreting Fault Codes
5. Common Fault Types and Solutions 5.1 Overcurrent Faults (OC1/OC2/OC3) 5.2 Overload Faults (OL1/OL2) 5.3 Phase Loss Faults (SP1/SP0) 5.4 Overvoltage/Undervoltage Faults (OV1/OV2/UV) 5.5 Motor Parameter Autotuning Faults (TE) 5.6 External Faults (EF)
6. Principles and Troubleshooting of Motor Parameter Autotuning 6.1 Purpose and Process of Autotuning 6.2 Causes and Solutions for Autotuning Failures
7. Maintenance and Upkeep of Inverters 7.1 Daily Maintenance Checklist 7.2 Periodic Maintenance Procedures 7.3 Replacement of Wear-Prone Components
8. Advanced Fault Diagnosis Techniques 8.1 Using Oscilloscopes for Signal Analysis 8.2 Diagnosing Issues via Analog Inputs and Outputs 8.3 Remote Monitoring through Communication Functions
9. Case Studies 9.1 Case Study 1: “END” Fault Due to Failed Motor Parameter Autotuning 9.2 Case Study 2: TRIP Light Illumination Caused by Overcurrent 9.3 Case Study 3: Inverter Shutdown Due to Input Phase Loss
10. Preventive Measures and Best Practices 10.1 Avoiding Common Faults 10.2 Best Practices for Parameter Settings 10.3 Environmental Factors Affecting Inverters
11. Conclusion

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1. Introduction

Inverters are pivotal components in modern industrial automation systems, widely used for motor control, energy conservation, and precise speed regulation. The Anruiji E6 series inverters are renowned for their high performance, reliability, and extensive functionality. However, inverters can encounter various faults during operation, such as the “END” fault and TRIP light illumination, which can disrupt production and potentially damage equipment.

This article focuses on the Anruiji E6 series inverters, providing an in-depth analysis of the causes, diagnostic methods, and solutions for “END” faults and TRIP light illumination. Combined with practical case studies, this guide offers a systematic approach to troubleshooting and maintenance, helping engineers and technicians quickly identify and resolve issues to restore production efficiency.

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2. Fundamentals of Inverters

2.1 How Inverters Work

Inverters adjust the frequency and voltage of the input power supply to achieve precise control of AC motors. Key components include:

• Rectifier Unit: Converts AC power to DC power.
• Filter Unit: Smooths the DC voltage.
• Inverter Unit: Converts DC power back to adjustable frequency and voltage AC power.
• Control Unit: Adjusts output frequency and voltage based on set parameters and feedback signals.

2.2 Technical Specifications of Anruiji E6 Series Inverters

The Anruiji E6 series inverters feature:

• Input/Output Characteristics:
  • Input Voltage Range: 380V/220V ±15%
  • Output Frequency Range: 0~600Hz
  • Overload Capacity: 150% rated current for 60s, 180% rated current for 10s
• Control Modes:
  • Sensorless Vector Control (SVC)
  • V/F Control
  • Torque Control
• Functional Features:
  • PID Control, Multi-Speed Control, Swing Frequency Control
  • Instantaneous Power Loss Ride-Through, Speed Tracking Restart
  • 25 types of fault protection functions

2.3 Core Functions and Applications

Inverters are widely used in:

• Fans and Pumps: Achieving energy savings through speed regulation.
• Machine Tools and Injection Molding Machines: Precise control of speed and torque.
• Cranes and Elevators: Smooth start/stop operations to reduce mechanical stress.
• Textile and Fiber Industries: Swing frequency control for uniform winding.

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3. Basic Fault Diagnosis Process

3.1 Classification of Fault Phenomena

Inverter faults can be categorized as:

• Hardware Faults: Such as IGBT damage, capacitor aging, and loose connections.
• Parameter Faults: Incorrect parameter settings or failed autotuning.
• Environmental Faults: Overheating, high humidity, and electromagnetic interference.
• Load Faults: Motor stalling, excessive load, or mechanical jamming.

3.2 Steps for Fault Diagnosis

1. Observe Fault Phenomena: Note display messages and indicator light statuses.
2. Check Fault Codes: Retrieve specific fault codes via the panel or communication software.
3. Analyze Possible Causes: Refer to the manual to list potential causes based on fault codes.
4. Systematic Troubleshooting: Start with simple checks and progress to more complex issues.
5. Verification and Repair: After fixing the fault, restart the inverter to verify the solution.

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4. In-Depth Analysis of “END” Faults and TRIP Light Illumination

4.1 Definition and Manifestation of Faults

• “END” Display: Typically appears after motor parameter autotuning or parameter setting completion. If accompanied by the TRIP light, it indicates a fault during autotuning or operation.
• TRIP Light Illumination: Indicates that the inverter has triggered a fault protection and stopped output.

4.2 Possible Causes of Faults

1. Failed Motor Parameter Autotuning:
   • Motor not disconnected from the load (autotuning requires no load).
   • Incorrect motor nameplate parameters (F2.01~F2.05).
   • Inappropriate acceleration/deceleration times (F0.09, F0.10) causing overcurrent.
2. Overcurrent Faults:
   • Motor stalling or excessive load.
   • Unstable input voltage (undervoltage or overvoltage).
   • Mismatch between inverter power and motor power.
3. Overload Faults:
   • Motor operating under high load for extended periods.
   • Overload protection parameter (Fb.01) set too low.
4. Input/Output Phase Loss:
   • Loose connections in input (R, S, T) or output (U, V, W).
5. Overvoltage/Undervoltage:
   • Significant input voltage fluctuations.
   • Short deceleration time causing energy feedback and bus overvoltage.

4.3 Viewing and Interpreting Fault Codes

• Press PRG/ESC or DATA/ENT to view specific fault codes (e.g., OC1, OL1, TE).
• Refer to the “Fault Information and Troubleshooting” section in the manual to find solutions based on fault codes.

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5. Common Fault Types and Solutions

5.1 Overcurrent Faults (OC1/OC2/OC3)

Causes:

• Acceleration time too short (F0.09).
• Motor stalling or excessive load.
• Low input voltage.

Solutions:

• Increase acceleration time (F0.09).
• Check motor and load for mechanical jamming.
• Verify input voltage stability.

5.2 Overload Faults (OL1/OL2)

Causes:

• Motor operating under high load for extended periods.
• Overload protection parameter (Fb.01) set too low.

Solutions:

• Adjust overload protection current (Fb.01).
• Check motor cooling and load conditions.

5.3 Phase Loss Faults (SP1/SP0)

Causes:

• Loose input or output connections.
• Incorrect wiring of power source or motor.

Solutions:

• Check input (R, S, T) and output (U, V, W) connections.
• Ensure no short circuits or open circuits in power source or motor wiring.

5.4 Overvoltage/Undervoltage Faults (OV1/OV2/UV)

Causes:

• Significant input voltage fluctuations.
• Short deceleration time causing energy feedback and bus overvoltage.

Solutions:

• Increase deceleration time (F0.10).
• Install braking resistors or units.
• Check input voltage stability.

5.5 Motor Parameter Autotuning Faults (TE)

Causes:

• Incorrect motor parameters.
• Motor not disconnected from the load.
• Autotuning timeout.

Solutions:

• Re-enter motor nameplate parameters (F2.01~F2.05).
• Ensure motor is unloaded.
• Set appropriate acceleration/deceleration times (F0.09, F0.10).

5.6 External Faults (EF)

Causes:

• External fault input terminal activation.
• Communication faults (CE).

Solutions:

• Check external fault input signals.
• Verify communication lines and baud rate settings.

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6. Principles and Troubleshooting of Motor Parameter Autotuning

6.1 Purpose and Process of Autotuning

Motor parameter autotuning aims to obtain precise motor parameters (e.g., stator resistance, rotor resistance, inductance) to enhance control accuracy. The process includes:

1. Set F0.13=1 (Full Autotuning).
2. Press RUN to start autotuning.
3. The inverter drives the motor and calculates parameters.
4. Upon completion, parameters are automatically updated to F2.06~F2.10.

6.2 Causes and Solutions for Autotuning Failures

Cause	Solution
Motor not unloaded	Ensure motor is disconnected from load
Incorrect parameters	Re-enter motor nameplate parameters (F2.01~F2.05)
Short acceleration/deceleration times	Increase F0.09, F0.10
Incorrect motor wiring	Check U, V, W connections
Unstable power supply	Verify input voltage

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7. Maintenance and Upkeep of Inverters

7.1 Daily Maintenance Checklist

• Check environmental temperature and humidity.
• Ensure fan operates normally.
• Verify input voltage and frequency stability.

7.2 Periodic Maintenance Procedures

Check Item	Check Content	Action
External Terminals	Loose screws	Tighten
PCB Board	Dust, debris	Clean with dry compressed air
Fan	Abnormal noise, vibration	Clean or replace
Electrolytic Capacitors	Discoloration, odor	Replace

7.3 Replacement of Wear-Prone Components

• Fans: Replace after 20,000 hours of use.
• Electrolytic Capacitors: Replace after 30,000 to 40,000 hours of use.

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8. Advanced Fault Diagnosis Techniques

8.1 Using Oscilloscopes for Signal Analysis

• Check input/output voltage waveforms for distortions or phase loss.
• Analyze analog input/output signals for interference.

8.2 Diagnosing Issues via Analog Inputs and Outputs

• Verify A11, A12 inputs are normal.
• Check AO1, AO2 outputs match settings.

8.3 Remote Monitoring through Communication Functions

• Use Modbus communication to read real-time inverter data.
• Remotely adjust parameters to avoid on-site operation risks.

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9. Case Studies

9.1 Case Study 1: “END” Fault Due to Failed Motor Parameter Autotuning

Phenomenon: Inverter displays “END”, TRIP light illuminated. Cause: Motor not disconnected from load, autotuning timeout. Solution:

1. Disconnect motor from load.
2. Re-enter motor parameters (F2.01~F2.05).
3. Restart autotuning (F0.13=1).

9.2 Case Study 2: TRIP Light Illumination Caused by Overcurrent

Phenomenon: Inverter shuts down during operation, displays OC1. Cause: Acceleration time too short, motor stalling. Solution:

1. Increase acceleration time (F0.09=20s).
2. Check motor load for jamming.

9.3 Case Study 3: Inverter Shutdown Due to Input Phase Loss

Phenomenon: Inverter fails to start, displays SP1. Cause: Input power source R phase loss. Solution:

1. Check input connections, ensure R, S, T are connected.
2. Restart inverter, fault cleared.

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10. Preventive Measures and Best Practices

10.1 Avoiding Common Faults

• Regularly check connections and environment.
• Set reasonable acceleration/deceleration times and overload protection parameters.
• Avoid frequent starts/stops to reduce mechanical stress.

10.2 Best Practices for Parameter Settings

• Accurately set motor parameters (F2.01~F2.05) based on nameplate.
• Optimize carrier frequency (F0.12) to balance noise and efficiency.
• Enable AVR function (F0.15) to improve voltage stability.

10.3 Environmental Factors Affecting Inverters

• Avoid high temperature, humidity, and dusty environments.
• Ensure good ventilation to prevent overheating.

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11. Conclusion

The “END” fault and TRIP light illumination in Anruiji E6 series inverters are typically caused by failed motor parameter autotuning, overcurrent, overload, phase loss, and other issues. Through a systematic fault diagnosis process, combined with fault codes and practical case studies, issues can be quickly identified and resolved. Regular maintenance and proper parameter settings are crucial for ensuring the long-term stable operation of inverters. Engineers should be familiar with the working principles and fault characteristics of inverters to enhance the efficiency and accuracy of troubleshooting.