Category: Mitsubishi

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Mitsubishi E700 (E740) Inverter E.AIE Fault Code: Analog Input Error Analysis and Solutions

1. Introduction

The Mitsubishi E700 series inverters, including the E740 model, are widely used high-performance devices in industrial automation, renowned for their efficiency, stability, and flexibility. However, during operation, these inverters may encounter faults, with the “E.AIE” fault code (Analog Input Error) being a common issue. This article provides an in-depth analysis of the E.AIE fault’s meaning, potential causes, and systematic troubleshooting steps and solutions to help users quickly identify and resolve the issue. Additionally, preventive measures are discussed to minimize the occurrence of similar faults.

FR-E740

2. Meaning of the E.AIE Fault Code

According to the Mitsubishi E700 Inverter Manual (hereinafter referred to as the manual), the E.AIE fault code indicates an abnormality in the analog input. This fault is typically related to the analog input signals (e.g., 0-10V voltage or 4-20mA current) received through terminals (such as terminals 2 or 4), which are used to set motor operating frequency or other control parameters. When the inverter detects that these signals are out of range, missing, or unstable, it triggers the E.AIE protection function, halting output and displaying the fault code on the operation panel.

Possible Triggering Conditions

  1. Signal Out of Range: Input signal exceeds the inverter’s supported range (e.g., voltage > 10V or current > 20mA).
  2. Signal Transmission Issues: Wiring problems or electromagnetic interference causing signal interruption or distortion.
  3. External Device Failure: Malfunction of devices providing the signal (e.g., potentiometers, sensors, or PLCs).
  4. Parameter Setting Errors: Incorrect settings for parameters related to analog input, such as PR.73 and PR.267.
  5. Internal Inverter Issues: Damage to the analog input circuit.

Understanding the meaning of E.AIE allows for a multi-angle analysis of its causes and the development of troubleshooting strategies.

3. Possible Causes of the E.AIE Fault

The E.AIE fault may stem from external factors or issues within the device itself. The following is a detailed breakdown of potential causes:

3.1 Abnormal Analog Input Signal

The analog input signal is typically provided by an external device to control frequency or parameters. The manual (PAGE 71) notes that the E700 series supports 0-5V, 0-10V voltage inputs, and 4-20mA current inputs. If the signal exceeds these ranges, the inverter triggers protection.

  • Possible Issues:
    • Abnormal output from an external device (e.g., voltage exceeding 10V).
    • Unstable or missing signal.
  • Example: A damaged potentiometer causing voltage fluctuations, or a PLC output module failing, resulting in current exceeding 20mA.

3.2 Wiring Issues

Wiring problems are a common cause of analog input abnormalities. The manual (PAGE 19 and PAGE 23) provides detailed wiring requirements for control circuit terminals.

  • Possible Issues:
    • Loose or Disconnected Wiring: Poor contact at terminals 2 (voltage input), 4 (current/voltage input), or 5 (common terminal).
    • Wiring Errors: Voltage signal mistakenly connected to a current terminal, or the common terminal not properly connected.
    • Electromagnetic Interference: Unshielded signal lines or proximity to power lines causing signal distortion.
  • Example: Signal lines not using shielded cables, affected by electromagnetic interference from nearby motor operation.

3.3 External Device or Sensor Failure

Analog signals are often sourced from external devices such as potentiometers, sensors, or PLCs. If these devices fail, it can lead to signal abnormalities.

  • Possible Issues:
    • Aged potentiometer causing unstable voltage output.
    • Damaged sensor interrupting the 4-20mA current signal.
    • Abnormal power supply to external devices affecting signal output.
  • Example: A 4-20mA pressure sensor outputting abnormal current due to an internal short circuit.

3.4 Parameter Setting Errors

Inverter parameter settings directly affect analog input recognition. The manual (PAGE 49 and PAGE 71) highlights key parameters:

  • PR.73 (Analog Input Selection): Defines the input type for terminal 2 (e.g., 0-10V or 4-20mA).
  • PR.267 (Terminal 4 Input Selection): Defines the input type for terminal 4, supporting 0-5V, 0-10V, or 4-20mA.
  • PR.125/PR.126 (Frequency Setting Gain): Calibrates the relationship between analog signals and frequency.
  • Possible Issues: Mismatched settings for PR.73 or PR.267 with the actual signal type, preventing correct signal recognition.
  • Example: PR.267 set to “0” (4-20mA) while the actual input is a 0-10V signal, leading to a read error.

3.5 Internal Inverter Circuit Failure

If external signals and wiring are normal but the fault persists, it may indicate a hardware issue.

  • Possible Issues:
    • Damage to the analog input circuit (e.g., A/D conversion module).
    • Aging or moisture-related degradation of internal circuits.
  • Example: Long-term operation in a humid environment causing circuit board corrosion.
E.AI E

4. Role of PR.267 in the E.AIE Fault

PR.267 is a critical parameter related to analog input, specifically used to set the input type for terminal 4. According to the manual (PAGE 71), PR.267 options include:

  • 0: 4-20mA current input.
  • 1: 0-5V voltage input.
  • 2: 0-10V voltage input.

The purpose of PR.267 is to inform the inverter how to interpret the analog signal received via terminal 4. For instance, if PR.267 is set to “0,” the inverter expects a 4-20mA current signal; if set to “2,” it expects a 0-10V voltage signal.

Relationship Between PR.267 and E.AIE Fault

When the PR.267 setting does not match the actual input signal type, the inverter may fail to recognize or process the signal correctly, triggering an E.AIE fault.

  • Mismatch Example: If PR.267 is set to “0” (current input) but the input is a voltage signal, the inverter misinterprets the data, leading to an E.AIE error.
  • Signal Out of Expected Range: Even with the correct signal type, if the PR.267 setting causes the inverter to expect a range that differs from the actual input (e.g., voltage input but exceeding 10V), a fault may occur.

Thus, checking the PR.267 setting is essential during E.AIE fault troubleshooting.

5. Steps to Resolve the E.AIE Fault

Based on the above causes, the following are systematic troubleshooting and resolution steps:

5.1 Check the Analog Input Signal

  • Action:
    • Use a multimeter to measure the signal between terminals 2 (voltage input) or 4 (current/voltage input) and terminal 5.
    • Verify the signal is within the normal range (0-5V, 0-10V, or 4-20mA).
  • Solution:
    • If the signal exceeds the range, adjust the external device output.
    • If the signal is missing, check the external device’s operation.

5.2 Inspect Wiring and Shielding

  • Action:
    • Check the integrity of terminals 2, 4, and 5 wiring, referring to the manual (PAGE 15) for the wiring diagram.
    • Ensure signal lines use shielded cables with the shield grounded (PAGE 33).
  • Solution:
    • Tighten loose terminals or replace damaged wiring.
    • Install shielded cables and keep them away from power lines to reduce interference.

5.3 Test External Devices

  • Action:
    • Disconnect the external device and use a signal generator to input a standard signal, observing if the fault disappears.
  • Solution:
    • If the fault resolves with a direct input, inspect and replace the faulty external device.

5.4 Check Parameter Settings (Focus on PR.267)

  • Action:
    • Enter parameter mode to verify PR.73 (terminal 2) and PR.267 (terminal 4) match the input signal types.
    • Specific steps:
      • Check the current value of PR.267.
      • Confirm the actual signal type at terminal 4 (voltage or current).
      • Adjust PR.267 to the matching value (e.g., “2” for 0-10V).
    • Verify PR.125 and PR.126 are correctly calibrated (PAGE 70).
  • Solution:
    • Adjust PR.73 and PR.267 to the correct values.
    • If unsure, reset parameters to factory settings (PAGE 42) and reconfigure.

5.5 Inspect Inverter Hardware

  • Action:
    • Check terminals for signs of burning or damage.
    • If possible, replace the control board for testing.
  • Solution:
    • If hardware failure is confirmed, contact Mitsubishi service or a professional technician (PAGE 113).

5.6 Reset and Test

  • Action:
    • Press the “STOP/RESET” key to reset the fault (PAGE 95).
    • Restart the inverter and conduct a trial run.
  • Solution:
    • If the fault persists, repeat the steps or seek technical support.

6. Preventive Measures

To reduce the occurrence of E.AIE faults, consider the following measures:

  1. Regular Wiring Checks: Inspect terminal integrity and signal line condition monthly.
  2. Use Quality Equipment: Select external devices compatible with the inverter.
  3. Optimize Installation Environment: Follow manual guidelines (PAGE 14) to avoid harsh conditions.
  4. Parameter Backup and Verification: Back up parameters after initial setup and periodically check PR.267 and other key settings.
  5. Regular Maintenance: Clean the inverter annually and inspect internal circuits as recommended (PAGE 113).

7. Case Study

Consider a FR-E740-7.5K-CHT inverter displaying an E.AIE fault:

  • Troubleshooting: Measurement shows a 0-10V voltage input at terminal 4, but PR.267 is set to “0” (4-20mA).
  • Root Cause: PR.267 mismatch with the actual signal type.
  • Solution: Adjust PR.267 to “2” (0-10V), reset the inverter, and the fault is cleared.
  • Prevention: Record PR.267 settings and regularly inspect external devices.

8. Conclusion

The E.AIE fault in Mitsubishi E700 (E740) inverters is typically caused by abnormal analog input signals, wiring issues, external device failures, parameter setting errors (especially PR.267), or internal hardware damage. By inspecting signals, wiring, devices, parameters, and hardware, users can effectively resolve the issue. Notably, correctly setting PR.267 is crucial to avoiding E.AIE faults. Preventive measures, such as regular parameter checks and backups, enhance equipment reliability. If troubleshooting proves challenging, contacting Mitsubishi technical support is recommended to ensure production efficiency and equipment safety.

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    Implementation Plan for Automated Control System of Mooncake Production Line

    Based on Longi 900 Series Inverter and Mitsubishi FX3U PLC

    1. Project Background

    Mooncakes are a traditional Chinese delicacy with cultural significance, especially during the Mid-Autumn Festival. With increasing market demand for quality, production capacity, and hygiene standards, traditional manual production methods have become inadequate. Therefore, building an efficient, stable, and intelligent automated mooncake production system is crucial.

    This project proposes an automation control system integrating the Mitsubishi FX3U PLC, Weintek HMI, and Rongji 900 series inverter to manage the entire mooncake manufacturing process—from dough and filling feeding, encrusting, pressing, forming, tray loading, baking, cooling, to final packaging. The system aims to provide a flexible, reliable, and cost-effective solution for small to medium-sized food manufacturers.

    Schematic Diagram of Mooncake Production Line

    2. Detailed Workflow and Production Line Principle

    2.1 Overall Operating Principle

    The mooncake production line consists of a series of interconnected machines controlled by PLC logic, frequency inverters, and HMI interfaces. Key mechanisms include:

    • Synchronization of multiple machines via conveyor belts;
    • Detection of workpiece positions using photoelectric sensors;
    • Speed control of motors via inverters for precise encrusting, molding, and tray feeding;
    • Time-sequenced logic from the PLC ensures no process conflicts;
    • Real-time monitoring and parameter setting via HMI.

    2.2 Detailed Workflow Breakdown

    StageDescription
    1. Raw Material FeedingDough and filling are independently fed via hoppers. Dough is delivered using screw or belt feeders, while filling (e.g., lotus paste, egg yolk) is fed by twin-screw or extrusion pumps.
    2. EncrustingAn automatic encrusting machine proportionally wraps dough around the filling. Three synchronized feeding systems ensure consistent weight and shape of each mooncake ball.
    3. Molding and PressingMooncake balls are first shaped by a vibrating pre-former, then enter the press system. The top-down mold structure creates floral patterns and sets thickness using pneumatic or servo mechanisms.
    4. Conveying & AlignmentMolded mooncakes are neatly aligned by guide rails and pushed into baking trays using mechanical pushers. The process is synchronized to avoid overlaps or gaps.
    5. BakingMulti-zone tunnel ovens provide accurate heat distribution (e.g., upper/lower heat). Temperature sensors and alarms ensure safe operation. Advanced models may include vision-based feedback control.
    6. CoolingAfter baking, mooncakes cool for 5–10 minutes via mesh-belt forced-air systems. Adjustable air speed/direction ensures even cooling, with flipping mechanisms for underside exposure.
    7. InspectionMetal detectors and weight checkers remove defective or foreign-object-containing products.
    8. PackagingQualified mooncakes are guided by robotic arms or channels into packaging machines for automatic wrapping, sealing, coding, and boxing. The system synchronizes with the conveyor line via PLC signals.

    This line typically supports 50,000 to 200,000 pieces/day with a throughput of 60–120 pieces per minute and easily accommodates various flavors and sizes.

    Automatic Mooncake Production Line

    3. System Architecture

    3.1 Mitsubishi FX3U PLC

    • Manages all I/O signals (e.g., sensors, buttons, alarms);
    • Includes main program, interrupt routines, and PID modules for real-time operation;
    • MODBUS-compatible for seamless communication with Rongji inverters;
    • Expandable with high-speed counting modules for precise positioning.

    3.2 Rongji 900 Series Inverter

    • Drives dough feeders, encrusters, mold presses, tray pushers, etc.;
    • Supports VF and SVC modes for high torque at low speeds;
    • Built-in PID for closed-loop control (e.g., pressure in mold presses);
    • Multi-speed (F4) support with 8-step preset frequencies;
    • Rich I/O terminals for flexible integration.

    3.3 Weintek HMI (e.g., TK6071iQ)

    • Communicates with PLC via RS-232 or MODBUS-RTU;
    • Enables menu control, recipe switching, alarms, and statistics;
    • Supports USB recipe import/export and data logging for quality control.
    Mooncake Production Control System

    4. Sample Control Logic

    Encrusting Module

    • DI1: Start signal
    • AI1: Speed reference (from HMI or upper system)
    • DO1: Completion signal to trigger the next stage

    Molding Module

    • PLC monitors position sensor and triggers press motor;
    • Rongji 900 inverter reads pressure sensor input via AI and uses PID to maintain consistent pressing force.

    Tray Loading Module

    • PLC controls solenoid valves and pushers based on production rhythm;
    • Light sensors detect tray availability;
    • System halts and alarms when trays are missing.

    5. Advantages of Longi 900 Series Inverter

    The longi 900G3 inverters demonstrated the following key strengths in this project:

    • Strong Low-Speed Torque: 150% torque at 0.5Hz ensures stable encrusting and precise tray loading;
    • Flexible Control Modes: VF and SVC switching adapts to fast feeding and slow pressing tasks;
    • Built-in PID: Reduces PLC workload and hardware requirements;
    • Compact and Cost-Effective: Ideal for upgrading production lines in small/medium food factories;
    • Simple, Reliable Communication: Easy-to-configure MODBUS registers speed up commissioning.

    6. Conclusion

    This automation system combines Mitsubishi FX3U PLC, Rongji 900 inverters, and Weintek HMI to create a comprehensive, efficient, and stable mooncake production solution. It features flexible parameter settings, smooth operation, high productivity, and easy scalability and maintenance.

    As a key drive component, the Longi inverter stands out for its excellent performance and affordability—making it not only ideal for this project, but also highly recommended for other food processing lines such as pastry, frozen food, and beverage packaging.

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    LTI Motion ServoC Servo Drive Application Solution for Ceramic Rolling Forming Equipment (Based on Mitsubishi FX-3U Series PLC)

    1. Overview
    Ceramic rolling forming equipment is a typical multi-axis automatic machine widely used in the initial pressing of electronic, structural, and functional ceramics. The system usually consists of a servo control unit, electrical control system, pneumatic components, and a rolling head. This document introduces in detail how to apply the LTI Motion ServoC series servo drive in combination with the Mitsubishi FX3U series PLC, covering the application strategy, wiring diagram, parameter configuration, and control logic.

    ServoCplus

    2. Application Scenario and System Structure
    This system involves two servo control units:

    • Pressing Axis Servo: Drives the pressing roller vertically to compress ceramic blanks.
    • Rotary Table Servo: Controls intermittent indexing of the rotary table for sequential forming.

    3. Key Functional Requirements

    • Precise positioning of the pressing head for consistent product thickness.
    • Indexing rotation of the rotary table with accurate angular control.
    • Multi-sensor interlock with limit switches and origin sensors.
    • Safety integration with emergency stops, alarms, and feedback loops.

    4. Hardware and Wiring Configuration

    • PLC: Mitsubishi FX3U-48MR/ES-A
    • Servo Drive: ServoC SGS4.0750.0012.0000.0 (LTI Motion)
    • Motor: Matching LTI servo motor (1.5~2.2kW)
    • Power Supply: 3-phase 400VAC

    5. Detailed Servo Wiring
    5.1 Pressing Servo (I/O Mode Control)

    ServoC TerminalFunctionConnect to PLC
    ISD00STR (Forward)Y2
    ISD01STL (Reverse)Y3
    ENPOEnableY4
    DGNDGround0V

    5.2 Rotary Table Servo (Pulse + Direction Mode)

    ServoC TerminalFunctionConnect to PLC
    ME_A+Pulse+Y0
    ME_B+Direction+Y1
    ENPOEnableY4

    5.3 Sensor Inputs

    SensorDescriptionConnect to PLC
    Origin SensorPressing Axis HomeX3
    Bottom SensorPressed PositionX4
    Table SensorIndex CompleteX5
    LTI MOTION SC54

    6. ServoC Parameter Configuration

    • P145 = 4: Position control mode
    • P152 = 1 or 2: Set input mode to pulse+direction or I/O trigger
    • P210 = 2; P211 = 3: Set ISD00 to STR, ISD01 to STL
    • P483 = 2 or 3: Motor direction configuration
    • P759 / P760: Software limit for press upper/lower bounds
    • P803: Position error tolerance

    7. Control Logic Sequence

    1. Power ON → Y4 output to enable servos.
    2. Origin detection via X3 → Set M10 (homed flag).
    3. Start pressing:
      • X0 input triggers Y2 = ON (STR), Y3 = OFF (STL).
      • X4 bottom sensor triggers M20.
    4. Return press head:
      • X1 input triggers Y3 = ON (STL), Y2 = OFF.
    5. Rotate table:
      • X2 input + M20 triggers 2000 pulses via Y0 and DIR = Y1.
      • X5 confirms rotation complete (M31).

    8. Ladder Diagram (Simplified)

    LD M8013
OUT Y4 ; Servo Enable

LD X3
OUT M10 ; Homed flag

LD X0 AND M10
OUT Y2
RST Y3

LD X1 AND M10
OUT Y3
RST Y2

LD X4
OUT M20

LD X2 AND M20
RST M20
SET Y1
PLS Y0 K2000

LD X5
OUT M31
RST M30

    9. Diagrams and Application Notes

      ServoC_FX_ConnectionDiagram

      10. Conclusion and Recommendations
      This solution demonstrates the application of ServoC servo drives in high-precision ceramic roller forming machines using Mitsubishi FX3U PLCs.

      Best Practices:

      • Set software travel limits.
      • Implement emergency stops and feedback alarms.
      • Always home the servo before operation.
      • Use opto-isolated I/O to reduce interference.

      Future Extensions:

      • Integrate HMI for parameter recipes and alarms.
      • Add pressure sensors and linear encoders for quality control.
      • Expand to multi-station synchronization with communication protocols.
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      Mitsubishi FR-A700 Inverter E.ou2 Fault: Analysis and Solutions for Overvoltage During Constant Speed Operation

      Abstract

      This article provides a detailed analysis of the E.ou2 fault (overvoltage during constant speed operation) in the Mitsubishi FR-A700 series inverter. By integrating manual content with real-world application scenarios, it explores the causes, troubleshooting steps, and solutions to help users quickly diagnose and resolve the issue, ensuring stable equipment operation.

      Keywords

      Mitsubishi FR-A700, E.ou2 fault, overvoltage during constant speed, inverter, regenerative energy

      1. Introduction

      The Mitsubishi FR-A700 series inverters are widely recognized for their excellent performance in industrial motor control, particularly in applications like injection molding machines. However, during operation, inverters may trigger fault codes such as the user-reported “E.ou2.” According to the manual and the screenshot provided by the user, E.ou2 indicates an “overvoltage during constant speed operation,” meaning the main circuit DC voltage exceeds a safe threshold during fixed-speed operation, activating the protection mechanism. This article delves into this fault and offers practical solutions.

      E.OU2

      2. Definition and Causes of the E.ou2 Fault

      The E.ou2 fault is a protective error code in the Mitsubishi FR-A700 inverter, specifically denoting “overvoltage during constant speed operation.” When the inverter detects that the main circuit DC voltage surpasses the specified limit (typically related to the power supply voltage and device configuration, e.g., a threshold in a 400V system), it automatically stops output to safeguard the equipment. The primary causes of this fault include:

      • Excessive Regenerative Energy: During constant speed operation, the motor may generate significant regenerative energy due to load characteristics or mechanical inertia, feeding back into the inverter’s DC bus and raising the voltage.
      • Improper Parameter Configuration: For instance, if Pr.22 (stall prevention operation level) is set too low, it may fail to effectively suppress voltage fluctuations.
      • Abnormal Power or Load: Unstable power supply voltage or sudden load changes (e.g., process adjustments in an injection molding machine) may exacerbate regenerative energy production.

      3. Fault Manifestations and Real-World Case

      Based on the user-provided image, the inverter display clearly shows the “E.ou2” error code with the “RUN” light off, indicating that the device has stopped. This issue may occur in the following scenarios:

      • Time Pattern: The user noted that the equipment runs normally in the morning but frequently faults at noon, possibly due to rising environmental temperatures or changes in production load.
      • Industrial Environment: The image reveals dust accumulation on the inverter’s surface, suggesting prolonged operation in a harsh environment, which may impair heat dissipation and worsen the fault.

      4. Troubleshooting and Solutions

      To effectively address the E.ou2 fault, users are advised to follow these step-by-step troubleshooting and improvement measures:

      4.1 Parameter Check and Adjustment
      • Pr.22 (Stall Prevention Operation Level): Verify that this parameter is not lower than the motor’s no-load current. If it is, adjust it to a value higher than the no-load current to prevent erroneous protection triggers.
      • Pr.882 ~ Pr.886 (Regenerative Feedback Function): Enable and optimize these parameters to manage regenerative energy effectively. Refer to page 365 of the manual for specific settings.
      4.2 External Equipment Optimization
      • Braking Unit: If regenerative energy is significant, installing a braking unit to dissipate excess energy through resistors is recommended.
      • Common DC Bus Converter (FR-CV): For frequent overvoltage issues, using an FR-CV can efficiently absorb regenerative energy.
      • Power Supply Inspection: Use a multimeter or oscilloscope to check the input power stability, ensuring voltage fluctuations stay within the inverter’s allowable range.
      4.3 Environmental Improvements
      • Heat Dissipation Management: Ensure proper ventilation for the inverter, adding fans or air conditioning, especially during high-temperature periods (e.g., noon).
      • Cleaning Maintenance: Regularly remove dust from the inverter’s surface to prevent poor heat dissipation from causing cascading issues.
      4.4 Data Logging and Analysis
      • Operation Log: Record data such as load, speed, and environmental temperature at the time of the fault to identify potential patterns.
      • Fault History: Use the inverter’s MON mode to review historical fault records for diagnostic support.
      FR-A700

      5. Case Analysis and Recommendations

      Based on the user’s feedback and image data, the frequent occurrence of the E.ou2 fault at noon may be linked to the following factors:

      • Temperature Impact: Rising environmental temperatures at noon reduce heat dissipation efficiency, making DC bus voltage more likely to exceed limits.
      • Load Fluctuations: Production process adjustments may lighten the load, increasing regenerative energy.
        For this scenario, the following recommendations are suggested:
      1. Enhance heat dissipation measures during high-temperature periods, such as temporarily adding fans.
      2. Investigate load characteristics during noon hours and adjust operating parameters or processes as needed.
      3. Implement regular maintenance to ensure long-term equipment stability.

      6. Conclusion

      The E.ou2 fault is a common overvoltage issue in Mitsubishi FR-A700 inverters during constant speed operation. By optimizing parameter settings, installing external equipment, improving heat dissipation, and conducting regular maintenance, users can significantly reduce fault occurrence and enhance equipment reliability. The troubleshooting steps and solutions provided in this article are universally applicable to similar scenarios.

      7. References

      • Mitsubishi FR-A700 Series Inverter User Manual

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      User Guide for Mitsubishi FR-A500 (A540 and A520) Series Inverter

      The Mitsubishi FR-A500 series inverter, including models A540 and A520, is a widely used device in the field of industrial control. Its user manual serves as an essential guide for operating and maintaining the inverter. This article provides a detailed introduction to the operation panel functions, parameter settings, password management, external control, and fault handling of this series of inverters based on the user manual.

      FR-A540

      I. Introduction to Operation Panel Functions

      The operation panel (FR-DU04) of the Mitsubishi FR-A500 series inverter is the primary interface for users to interact with the inverter, offering a range of display and operation capabilities:

      • Display Functions: The operation panel can display real-time key parameters of the inverter, such as operating frequency, output current, output voltage, and alarm information, facilitating user monitoring of the inverter’s status.
      • Key Functions:
        • MODE Key: Used to switch between different operation modes, such as monitor mode, frequency setting mode, and parameter setting mode.
        • SET Key: Used to confirm set values or enter the parameter setting interface.
        • ↑ and ↓ Keys: Used to increase or decrease set values, adjusting parameters or frequencies.
        • FWD and REV Keys: Used to issue forward and reverse commands, respectively, controlling the motor’s rotation direction.
        • STOP RESET Key: Used to stop the inverter or reset faults.

      II. Parameter Initialization Settings

      During the use of the inverter, it may be necessary to restore parameters to their factory settings. Users can perform parameter initialization through the following steps:

      • Clear All Parameters: Set parameter Pr.77 to 1, then press and hold the SET key for more than 1.5 seconds to restore all parameters (except Pr.77, Pr.79, Pr.80, and Pr.81) to their factory settings.
      • Clear User Parameter Groups: To clear user-defined parameter groups, use parameters Pr.174 and Pr.176 to clear the first and second user parameter groups, respectively.

      III. Password Setting, Removal, and Parameter Access Restrictions

      To protect the inverter’s parameters from being modified arbitrarily, users can set parameter access restrictions through the following methods:

      • Parameter Write Protection Selection (Pr.77):
        • When set to 1, parameters can only be written when the inverter is stopped.
        • When set to 2, writing to all parameters is prohibited (factory setting).
        • When set to 0, parameter writing is allowed during operation (note: safety considerations apply).
      • Password Function: Although the FR-A500 series inverter does not directly provide a password setting function, parameter write protection through Pr.77 can indirectly achieve a certain level of access control.

      IV. External Control Functions

      The Mitsubishi FR-A500 series inverter supports external terminal control, allowing users to configure it flexibly according to actual needs.

      • External Terminal Forward/Reverse Control:
        • Use terminals STF (forward start) and STR (reverse start) for forward/reverse control. When the STF signal is activated, the inverter operates in the forward direction; when the STR signal is activated, it operates in reverse.
        • Parameter Settings: Ensure that Pr.79 (operation mode selection) is set to external operation mode or combined operation mode to enable external terminal control.
      • External Potentiometer for Frequency Setting and Speed Control:
        • Frequency Setting Terminals: Use terminals 2, 4, 5, and 10 (or AU terminal, depending on parameter settings) for analog frequency setting. Typically, a potentiometer is connected between terminals 10 (or AU) and 5, and the input voltage is adjusted by rotating the potentiometer to set the operating frequency.
        • Parameter Settings: Set Pr.73 to select the voltage input range (e.g., 0-5V, 0-10V, etc.); ensure that parameters such as Pr.125 (analog input filter time constant) are set appropriately to ensure the stability of frequency setting.
      FR-A540

      V. Fault Codes and Handling Methods

      The inverter may encounter various faults during operation, and the user manual provides detailed fault codes and handling methods. Below are some common fault codes and brief handling steps:

      • E.OC1 (Overcurrent Trip During Acceleration): Check if the load is too heavy, if the acceleration time is too short, and if the motor and cable insulation are in good condition.
      • E.OV1 (Regenerative Overvoltage Trip During Acceleration): Check if the power supply voltage is too high, if the deceleration time is too short, and if the braking resistor is damaged.
      • E.THM (Motor Overload Trip): Check if the motor load is too heavy, if the motor cooling is adequate, and if necessary, reduce the load or improve the cooling conditions.
      • E.UVT (Undervoltage Protection): Check if the power supply voltage is too low and if the power lines are properly connected.
      • E.FIN (Heat Sink Overheat): Check if the inverter’s heat sink is excessively dusty, if ventilation is adequate, and if necessary, clean the heat sink or improve ventilation conditions.

      When the inverter stops due to a fault, the operation panel displays the corresponding fault code. Users should refer to the user manual based on the fault code and take appropriate handling measures. After handling, press the STOP RESET key to reset the inverter and restart operation.

      VI. Conclusion

      The Mitsubishi FR-A500 (A540 and A520) series user manual is an essential guide for operating and maintaining the inverter. Through this article, users should be able to master the operation skills of the operation panel functions, parameter initialization settings, password management, external control, and fault handling. In practical applications, users should configure the inverter parameters reasonably according to specific needs to ensure stable and efficient operation of the inverter. Additionally, regularly consulting the user manual to stay informed about the latest features and technical advancements of the inverter is also an important way to enhance equipment management capabilities.

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      Operation Guide for Mitsubishi VFD FR-D700 （D740,D720）Series User Manual

      I. Introduction to VFD Operation Panel Functions
      The operation panel of the Mitsubishi VFD FR-D700 series(D740,D720) is straightforward, facilitating various settings and operations for users. The panel primarily includes the following buttons and a rotary potentiometer:

      Mitsubishi VFD FR-D700 Operation Panel Function Diagram

      RUN: Press this button to start the VFD.
      STOP/RESET: Press this button to stop the VFD or reset alarms.
      MODE: Mode switching button used to toggle between different setting and display modes.
      SET: Confirmation button used to confirm current settings or enter the next menu level.
      PU/EXT: Operation mode switching button used to switch between PU (operation panel) mode and EXT (external terminal) mode.
      Rotary Potentiometer: Used to manually adjust the output frequency of the VFD.

      Setting Operation Modes
      The VFD offers multiple operation modes, which can be set via parameter P79:

      P79=0: PU operation mode, controlled via buttons and the rotary potentiometer on the operation panel.
      P79=2: External operation mode, receiving start, stop, and speed commands via external terminals.

      II. Terminal Start/Stop and External Potentiometer Speed Adjustment
      Wiring Instructions
      To achieve terminal start/stop and external potentiometer speed adjustment, proper wiring to the corresponding terminals of the VFD is required. Typically, the wiring is as follows:

      STF (Forward Start): Connect to the normally open contact of an external start button or relay.
      STR (Reverse Start): If reverse function is needed, connect to the normally open contact of an external reverse start button or relay.
      SD (Stop): Connect to the normally closed contact of an external stop button or relay.
      RH, RM, RL (Speed Setting): These terminals are typically used to connect an external potentiometer for speed adjustment. Among them, RH and RL are connected to the two ends of the potentiometer, and RM is connected to the sliding contact of the potentiometer.

      Parameter Settings
      Apart from proper wiring, relevant parameters need to be set to ensure the VFD operates as expected:

      P79: Set to 2 to select external operation mode.
      Pr7, Pr8: Set acceleration and deceleration times respectively to suit different application needs.
      Pr9: Set the electronic overcurrent protection parameter to protect the VFD and motor from overcurrent damage.

      Mitsubishi VFD FR-D700 Series External Wiring Diagram

      III. VFD Fault Code Analysis and Solutions
      When faults occur in the Mitsubishi VFD FR-D700 series, corresponding error codes are displayed, allowing users to analyze and resolve the faults. Below are some common fault codes and their solutions:

      ER1: Overcurrent during acceleration. Check if the motor is overloaded, if there is a short circuit in the output, and if the acceleration time is set too short.
      ER2: Overcurrent during constant speed. Check for sudden changes in load, and if there is a short circuit in the output.
      ER3: Overcurrent during deceleration. Check for rapid deceleration, if there is a short circuit in the output, and if the motor’s mechanical brake is applied too early.
      OL: Overspeed prevention (overcurrent). Check if the motor is overloaded.
      TH: Motor overheat. Check if the motor is operating overloaded for a long time, if the ambient temperature is too high, and if the cooling system is functioning properly.
      PS: PU stop. Check if the STOP button on the operation panel is pressed.
      MT: Main circuit terminal abnormality. Check if the connections of the main circuit terminals are loose or damaged.
      uV: Undervoltage protection. Check if the power supply voltage is too low, and if there is a large-capacity motor starting up causing instantaneous voltage drop.

      Solutions
      For overcurrent faults (ER1, ER2, ER3, OL): First, check if the motor and load are normal, then adjust acceleration time, deceleration time, and electronic overcurrent protection parameters.
      For overheating faults (TH): Improve the motor’s cooling conditions, such as adding fans or lowering the ambient temperature.
      For PU stop (PS): Confirm if the STOP button was pressed by mistake; if not, check the related control circuits.
      For main circuit terminal abnormality (MT): Check and tighten the connections of the main circuit terminals, and replace if damaged.
      For undervoltage protection (uV): Check if the power supply voltage is stable, and consider adding a power supply voltage stabilizing device.

      The above is the operation guide for the Mitsubishi VFD FR-D700 series user manual, hoping to assist users in practical operations. If encountering other issues during use, it is recommended to refer to the detailed user manual of the VFD or contact professional technicians of longi for consultation.

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      Analysis of PLC-Based Variable Frequency Constant Pressure Water Supply System with One-to-Two Drive

      Introduction

      Variable frequency constant pressure water supply systems are essential for maintaining stable water pressure in pipeline networks. This article delves into a specific system configuration that employs a Programmable Logic Controller (PLC) and a frequency converter to control two water pumps in a one-to-two drive setup. The system ensures continuous and stable water supply by automatically adjusting the pump operations based on pipeline pressure.

      Mitsubishi PLC Constant Pressure Water Supply Circuit Diagram

      System Overview

      The system primarily consists of a frequency converter, a PLC, and two water pumps. The control mechanism leverages the PID (Proportional-Integral-Derivative) and other related functions of the frequency converter, in conjunction with the PLC, to achieve automatic constant pressure water supply. Additionally, the system is equipped with an automatic/manual switching function, allowing manual control of the water pumps in case of a frequency converter fault.

      Control Process

      The control process of the system is as follows:

      1. Initial Start-Up: When the pipeline pressure drops below the set value, the frequency converter starts the first pump (#1 pump).
      2. Full Speed Operation: After running at full speed for a predetermined period, if the pipeline pressure still does not reach the set value, the PLC switches the #1 pump from frequency conversion to power frequency operation.
      3. Second Pump Activation: The frequency converter then starts the second pump (#2 pump), adjusting its speed based on the pipeline pressure to maintain constant pressure.
      4. Pump Switching: As water demand decreases and pipeline pressure increases, if the #2 pump’s speed drops to zero but the pipeline pressure remains high, the PLC stops the #1 pump operating at power frequency, allowing the #2 pump to maintain constant pressure.
      5. Cycle Continuation: When the pipeline pressure drops again, the #2 pump is switched to power frequency operation, and the frequency converter starts the #1 pump, adjusting its speed to maintain constant pressure. This cycle continues indefinitely.

      Frequency Converter Settings

      For the system to function correctly, the frequency converter must be configured with specific parameters:

      • Start/Stop Control: Set to operate on external terminals.
      • Parking Mode: Configured for free parking to avoid impact during frequency conversion/power frequency switching.
      • PID Mode: Enabled, with the pressure setting value entered via the AUX terminal and the feedback signal entering via the VIN terminal.
      • Control Terminals: Configured to output contact actions for frequency conversion faults, zero speed, and full speed.
      Mitsubishi PLC Constant Pressure Water Supply Program Diagram 1
      Mitsubishi PLC Constant Pressure Water Supply Program Diagram 2
      Mitsubishi PLC Constant Pressure Water Supply Program Diagram 3
      Mitsubishi PLC Constant Pressure Water Supply Program Diagram 4

      PLC Control Wiring and Program

      The PLC control wiring diagram shows the integration of fault signals from the water pumps and frequency converter, summarized through relay KA2. The manual/automatic switching is controlled by relay KA1, while the frequency conversion/power frequency operation is interlocked via contactor contacts for enhanced safety.

      The PLC program is straightforward, consisting of four main steps (S20 to S23) that form a complete cycle. The switching time between frequency conversion and power frequency is adjustable via two potentiometers (D8030 and D8031) connected to the FX1S type PLC.

      The program utilizes step instructions combined with set and reset commands. Step control begins with the STL instruction, and upon completion of all steps, a RET instruction returns the program to the starting step (S0). The SET command energizes the coil, while the RST command de-energizes it. The ZRST command is used for batch resetting multiple coils.

      Technological Advancements and Alternative Solutions

      As technology progresses, frequency converters are becoming more advanced, with some models capable of one-to-three or even one-to-six configurations. Automated instruments can also perform the PID function, allowing the frequency converter to work passively. In some setups, the frequency converter drives only one pump in a fixed manner, with the second pump directly switched to power frequency when needed. This approach, combined with timely pressure regulation by the frequency converter, results in more stable pipeline pressure.

      Conclusion

      The PLC-based variable frequency constant pressure water supply system with a one-to-two drive is a reliable and efficient solution for maintaining stable water pressure in pipeline networks. By leveraging the capabilities of PLCs and frequency converters, the system automatically adjusts pump operations to meet changing water demands. As technology continues to evolve, alternative solutions and configurations will emerge, offering even greater flexibility and efficiency in water supply management.

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      n-depth Analysis and Maintenance Guide for Mitsubishi F1S Switching Power Supply

      In-depth Analysis and Maintenance Guide for Mitsubishi F1S Switching Power Supply

      In the field of modern industrial automation, the application of Mitsubishi PLCs (Programmable Logic Controllers) is extensive. As a critical component of PLCs, the stability and reliability of the switching power supply directly determine the operating efficiency of the entire system. This article takes the Mitsubishi F1S switching power supply as an example, deeply analyzing its circuit structure, working principle, and maintenance methods. The aim is to provide readers with a comprehensive and practical technical guide.

      I. Overview of Circuit Structure

      The Mitsubishi F1S switching power supply board is designed intricately, featuring two relatively independent 24V output structures (although somewhat isolated by L2, they can still be considered as two separate outputs). These two outputs not only provide stable 5V power supply for the PLC motherboard but also offer DC24V external control power for external measurement instruments and other devices. The power board is tightly connected to the motherboard through copper needle-shaped rigid wires, ensuring stable signal transmission.

      II. Detailed Explanation of Working Principle

      1. Input Filtering and Protection: After entering the power board through the L and N terminals of the PLC, the industrial frequency 220V power first passes through a bidirectional low-pass filter network composed of C1, C2, C4, and L1. This design effectively filters out high-frequency interference and improves the purity of the power supply. Meanwhile, the bidirectional filters L1 and L2 further isolate high-frequency interference pulses from both inside and outside the power supply, ensuring stable system operation. F1 serves as an overload protection fast-acting fuse, while TH1 acts as a temperature fuse, together constituting a dual protection mechanism for the power supply.
      2. Rectification and Oscillation: The filtered AC power passes through F1 and TH1 into the full-wave rectification circuit, where it is rectified to obtain a direct current voltage of approximately 280V. This voltage is sent to the oscillation and voltage-stabilizing circuit centered on STRG6551. STRG6551 is a power oscillation module with an integrated switching tube. Its 4 and 3 pins are the power supply terminals, while 1 and 2 pins are internally connected to the source and drain of the power switching tube. Additionally, pin 2 provides negative feedback for the switching operating current. Pin 5 is the feedback voltage input terminal, used to regulate the stability of the output voltage.
      3. Voltage Stabilization and Protection: The voltage induced by the secondary winding of the switching transformer TB1 undergoes rectification and filtering before serving as the working power for the PLC. To maintain voltage stability, the system employs an output voltage sampling circuit composed of R9, IC2, PC1, and other components. When the voltage changes, this change is converted into a variation in the input current on the PC1 optocoupler device, which is then fed into pin 5 of STRG6551 through R4. The comparison amplification circuit inside STRG6551 adjusts the conduction/cutoff time of the switching tube, i.e., controls the duty cycle of the oscillation frequency, to achieve stable output voltage.

      Furthermore, the system boasts a comprehensive protection mechanism. When an abnormal load causes a sharp increase in current, the voltage variation across the sampling resistor R2 is introduced into pin 5 of STRG6551, reducing the output voltage to decrease the load current. When the voltage or current anomaly reaches a certain threshold, STRG6551 disconnects the driving circuit of the switching tube, causing the circuit to oscillate and protecting the subsequent circuit from damage.

      III. Maintenance Methods and Practices

      Faced with potential faults in the Mitsubishi F1S switching power supply, reasonable troubleshooting steps and scientific maintenance methods are crucial for improving maintenance efficiency. Here are some common maintenance methods:

      1. Routine Inspection: First, check whether the F1 and TH1 fuses are blown. If they are blown and there are no abnormal short-circuit points in the switching tube and load circuit, replacing the fuses generally resolves the issue. If the power still does not oscillate after replacing the fuses, further investigation is needed.
      2. Identify Fault Circuits: Disconnect the PLC motherboard, use a voltage regulator to adjust the input voltage to below AC100V, and connect a dummy load (such as a 100Ω 5W resistor). Short-circuit pins 1 and 2 of the PC1 optocoupler to make the voltage feedback signal zero. Power on and observe the power output. If there is output but not at a stable voltage, the fault lies in the voltage-stabilizing circuit; if there is no output, the fault is in the oscillation circuit.

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      Testing Method for Offline Operation of Mitsubishi MR-J3 Servo Driver Maintenance Board

      When repairing Mitsubishi servo drives, encountering damaged modules is common. After repairing such modules, it’s crucial to test the drive board’s output function offline before reinstallation. This article provides a detailed guide for testing a repaired Mitsubishi MR-J3-350A/3.5KW servo module.

      Mitsubishi Servo MR-J3 Circuit Board Maintenance Test Diagram

      Preparation for Offline Testing:

      1. Power Connection: Connect 300V DC voltage to power boards P2 and N to avoid E9 fault after power-on.
      2. Module Pad Hole Shielding:
        • Connect the 10 pins of the module pad hole to N.
        • Connect pad holes U, V, W to N to prevent AL24 fault.
        • Connect pad holes EV, EU, EW (upper axle drive trigger) to N.

      Parameter Setting Before Running:

      1. Change PA01: Set PA01 to 0002.
      2. Change PD01: Set PD01 to 0000.
      3. Power Board Connection: Connect P and D on the power board.
      4. Additional Power Board Connections: Connect L1 to L11 and L2 to L12 on the power board.
        • If PD parameters are not visible, change PA19 to 000C and power on again.
      Mitsubishi servo MR-J3 drive circuit actual pulse state

      Testing Process:

      • After following the above steps, power on and run the servo to test its 6-way waveform.
      • During parameter waveform testing, manually rotate the motor shaft to observe changes in pulse width and phase in the waveform. Note that this machine does not have a static cut-off negative voltage.

      By following this comprehensive guide, you can effectively test the offline operation of a repaired Mitsubishi MR-J3 servo driver maintenance board, ensuring its functionality before reinstallation.