Industrial control technology

Posted on 2025年11月8日2025年11月9日 by baiyuzhan

Comprehensive Analysis of AL-09 Overload Fault Diagnosis and Solutions for LS Servo Drive APD-VP Series

Introduction
Basic Concept of AL-09 Overload Fault 2.1 What is AL-09 Overload Fault? 2.2 Common Manifestations of AL-09 Fault
Structure and Working Principle of LS Servo Drive APD-VP Series 3.1 Hardware Structure of APD-VP Series Servo Drive 3.2 Control Logic and Feedback Mechanism of Servo Drive 3.3 Working Principle of Overload Protection Mechanism
Causes of AL-09 Fault 4.1 Mechanical Load Abnormalities 4.2 Electrical Parameter Setting Errors 4.3 Motor or Encoder Failures 4.4 Power Supply Issues 4.5 Environmental Factors
Diagnostic Steps for AL-09 Fault 5.1 Preliminary Inspection 5.2 Mechanical System Inspection 5.3 Electrical Parameter Inspection 5.4 Motor and Encoder Inspection 5.5 Power Supply and Wiring Inspection
Solutions for AL-09 Fault 6.1 Optimization and Adjustment of Mechanical Load 6.2 Reconfiguration of Electrical Parameters 6.3 Maintenance and Replacement of Motor and Encoder 6.4 Improvement of Power Supply Stability 6.5 Control of Environmental Factors
Preventive Measures for AL-09 Fault 7.1 Regular Maintenance and Upkeep 7.2 Parameter Backup and Optimization 7.3 Runtime Monitoring and Alarm System
Case Studies 8.1 Case Study 1: AL-09 Fault Caused by Mechanical Jamming 8.2 Case Study 2: AL-09 Fault Caused by Parameter Setting Errors 8.3 Case Study 3: AL-09 Fault Caused by Unstable Power Supply
Conclusion and Recommendations
References

1. Introduction

In the field of modern industrial automation, servo drives are core components for precise motion control, widely used in robotic arms, CNC machines, packaging machinery, and other equipment. The LS Electric APD-VP series servo drives are renowned for their high performance, reliability, and flexible control methods. However, in practical applications, servo drives may encounter various faults, with AL-09 overload faults being one of the most common issues. AL-09 faults not only cause equipment downtime but also severely impact the continuity and quality of production lines. Therefore, a deep understanding of the causes, diagnostic methods, and solutions for AL-09 faults is of significant practical importance for engineers and technicians.

This article comprehensively analyzes the causes, diagnostic steps, solutions, and preventive measures for AL-09 overload faults in the LS servo drive APD-VP series. It also validates these through practical case studies, aiming to provide a systematic and practical reference guide for relevant technical personnel.

2. Basic Concept of AL-09 Overload Fault

2.1 What is AL-09 Overload Fault?

AL-09 is an alarm code for LS servo drives, indicating an overload fault (Over Load). When the load on the servo motor exceeds its rated capacity during operation, the drive triggers the overload protection mechanism and displays the AL-09 alarm. Overload faults can be caused by various factors, including mechanical load abnormalities, electrical parameter setting errors, motor or encoder failures, and power supply issues.

2.2 Common Manifestations of AL-09 Fault

When a servo drive encounters an AL-09 fault, the following phenomena typically occur:

The drive’s display shows the “AL-09” alarm code.
The servo motor stops operating and cannot continue executing motion commands.
The alarm indicator light turns on, usually red or yellow.
The system may be accompanied by abnormal noises, such as motor humming or mechanical friction sounds.
The upper-level machine or PLC may receive alarm signals, causing the entire control system to shut down.

3. Structure and Working Principle of LS Servo Drive APD-VP Series

3.1 Hardware Structure of APD-VP Series Servo Drive

The LS servo drive APD-VP series adopts a modular design, primarily consisting of the following components:

Main Circuit Board: Includes IGBT inverters, PWM control circuits, current/voltage detection circuits, etc., responsible for converting input AC power into controllable three-phase AC power to drive the servo motor.
Control Circuit Board: Contains core control chips such as DSP (Digital Signal Processor) and FPGA (Field-Programmable Gate Array), responsible for motion control algorithms, parameter settings, communication interfaces, etc.
Interface Board: Provides various input/output interfaces, including analog input/output, pulse input, encoder feedback interfaces, etc., for communication with upper-level machines, PLCs, sensors, and other devices.
Power Supply Module: Supplies stable DC power to the internal circuits of the drive.
Cooling System: Includes heat sinks and fans to ensure stable operation of the drive under high loads.

3.2 Control Logic and Feedback Mechanism of Servo Drive

The APD-VP series servo drive employs a closed-loop control method, achieving precise motion control through the following steps:

Command Input: The upper-level machine (such as PLC or motion controller) sends motion commands (position, speed, or torque commands) to the drive.
Control Algorithm: The internal DSP of the drive calculates the control output based on the commands and feedback signals (such as encoder pulses and current sensor signals).
PWM Modulation: The control algorithm outputs PWM signals to drive the IGBT inverter, converting the DC bus voltage into variable frequency and amplitude three-phase AC power.
Motor Drive: The three-phase AC power drives the servo motor.
Feedback Detection: The encoder detects the motor’s position and speed in real-time, and the current sensor detects the actual current of the motor, sending feedback signals to the drive.
Closed-Loop Adjustment: The drive compares the commands and feedback signals and adjusts the output through the PID controller to achieve precise control.

3.3 Working Principle of Overload Protection Mechanism

The APD-VP series servo drive is equipped with an overload protection mechanism, which operates as follows:

Current Detection: The drive monitors the phase current of the motor in real-time. When the current exceeds the rated value, it triggers overload protection.
Torque Calculation: The drive calculates the actual output torque based on the current and motor parameters (such as torque constant). When the torque exceeds the set torque limit ([PE-205], [PE-206]), it triggers overload protection.
Load Monitoring: The drive calculates the actual load on the motor through encoder feedback and current detection. When the load exceeds the rated load (typically 300% of the rated torque), it triggers the AL-09 alarm.
Protection Action: Once overload protection is triggered, the drive immediately cuts off the PWM output, stopping the motor and displaying the AL-09 alarm code.

4. Causes of AL-09 Fault

The causes of AL-09 overload faults are diverse and can be categorized as follows:

4.1 Mechanical Load Abnormalities

Mechanical load abnormalities are the most common cause of AL-09 faults, including:

Mechanical Jamming: Transmission mechanisms (such as gears, guides, and screws) may jam or experience excessive friction, preventing the motor from rotating normally.
Excessive Load: The actual load exceeds the motor’s rated load capacity, such as overweight workpieces or unreasonable mechanical design.
Coupling Misalignment: The motor shaft and load shaft are misaligned, resulting in additional radial or axial forces that increase the motor load.
Insufficient Lubrication: Transmission components lack lubrication, increasing friction and motor load.

4.2 Electrical Parameter Setting Errors

Incorrect parameter settings in the drive can directly affect the motor’s operating state. Common parameter setting errors include:

Torque Limit Set Too Low: [PE-205] (CCW Torque Limit) and [PE-206] (CW Torque Limit) are set too low, causing the motor to trigger overload protection under normal loads.
Incorrect Gain Parameter Settings: Speed proportional gain ([PE-307], [PE-308]) or position proportional gain ([PE-302], [PE-303]) are set too high, leading to system oscillation or overload.
Electronic Gear Ratio Error: [PE-701] (Electronic Gear Ratio) is set incorrectly, causing a mismatch between pulse commands and actual positions, resulting in overload.
Encoder Pulse Number Setting Error: [PE-204] (Encoder Pulse Number) does not match the actual encoder, leading to incorrect feedback signals and triggering overload protection.

4.3 Motor or Encoder Failures

Failures in the motor or encoder can also cause AL-09 alarms:

Motor Winding Short Circuit or Open Circuit: Internal winding damage in the motor causes abnormal current increases.
Encoder Signal Loss or Error: Encoder damage or loose wiring causes interruption or error in feedback signals.
Motor Bearing Damage: Worn or jammed bearings increase the motor’s rotational resistance.

4.4 Power Supply Issues

The stability of the power supply directly affects the operation of the drive and motor:

Voltage Fluctuations: Unstable input voltage, such as overvoltage or undervoltage, causes abnormal drive output.
Poor Power Line Contact: Loose or oxidized power lines cause excessive voltage drops.
Regenerative Resistor Failure: Damaged regenerative resistors or incorrect parameter settings prevent effective absorption of regenerative energy, leading to overvoltage or overload.

4.5 Environmental Factors

Environmental factors can indirectly cause AL-09 faults:

High Temperature: Operation of the drive or motor in high-temperature environments leads to poor heat dissipation and performance degradation.
Humidity or Corrosive Gases: Moisture or corrosive environments may cause short circuits or poor contact in the circuit board.
Vibration or Impact: Mechanical vibration or impact may loosen or damage internal components of the drive.

5. Diagnostic Steps for AL-09 Fault

When the APD-VP series servo drive displays an AL-09 fault, follow these steps for diagnosis:

5.1 Preliminary Inspection

Confirm Alarm Code: Verify that the alarm code displayed on the drive is AL-09.
Check Mechanical Load: Manually rotate the motor shaft to confirm if there is jamming or abnormal resistance.
Check Power Supply: Ensure the input voltage is within the allowed range (AC200-230V) and the power line is normal.

5.2 Mechanical System Inspection

Inspect Transmission Mechanism:
- Ensure gears, guides, screws, and other transmission components are well-lubricated and free from jamming.
- Check if the coupling is aligned and free from offset or deformation.
Check Load:
- Confirm that the load is within the motor’s rated range, such as workpiece weight and mechanical friction.
- Reduce the load and observe if the fault disappears.

5.3 Electrical Parameter Inspection

Check Torque Limit:
- Enter menus [PE-205] and [PE-206] to confirm if the torque limit is set too low.
- If the torque limit is too low, increase the setting appropriately (usually not exceeding 300%).
Check Gain Parameters:
- Check if the speed proportional gain ([PE-307], [PE-308]) and position proportional gain ([PE-302], [PE-303]) are too high.
- If the gain is too high, gradually reduce the gain value and observe if the fault disappears.
Check Electronic Gear Ratio:
- Ensure [PE-701] (Electronic Gear Ratio) matches the mechanical transmission ratio.
Check Encoder Settings:
- Ensure [PE-204] (Encoder Pulse Number) matches the motor nameplate.

5.4 Motor and Encoder Inspection

Inspect Encoder:
- Ensure encoder wiring is secure and free from breaks or short circuits.
- Use an oscilloscope to check encoder signals (A, B, Z phases) for normality.
Inspect Motor:
- Measure the insulation resistance of the motor windings to ensure no short circuits or open circuits.
- Manually rotate the motor shaft to ensure bearings are free from abnormal noises or jamming.

5.5 Power Supply and Wiring Inspection

Check Power Supply:
- Use a multimeter to measure the input voltage, ensuring it is within the AC200-230V range.
- Check the power line for poor contact or oxidation.
Check Regenerative Resistor:
- Ensure the regenerative resistor is connected correctly and parameters are set reasonably.
- Check if the regenerative resistor is damaged and if the resistance value is normal.

6. Solutions for AL-09 Fault

Based on the diagnostic results, the following solutions can be implemented:

6.1 Optimization and Adjustment of Mechanical Load

Reduce Load:
- Lighten the workpiece weight or optimize the mechanical structure to reduce the motor load.
Lubricate Transmission Components:
- Regularly add lubricating oil or grease to gears, guides, screws, and other transmission components.
Adjust Coupling:
- Ensure the motor shaft and load shaft are aligned to avoid radial or axial forces.

6.2 Reconfiguration of Electrical Parameters

Adjust Torque Limit:
- Based on the actual load, appropriately increase the torque limit values in [PE-205] and [PE-206].
Optimize Gain Parameters:
- Gradually reduce the speed proportional gain ([PE-307], [PE-308]) and position proportional gain ([PE-302], [PE-303]) to avoid system oscillation.
Recalibrate Electronic Gear Ratio:
- Reset [PE-701] (Electronic Gear Ratio) according to the mechanical transmission ratio.

6.3 Maintenance and Replacement of Motor and Encoder

Replace Damaged Encoder:
- If the encoder signal is abnormal, replace it with a new one and ensure correct wiring.
Repair or Replace Motor:
- If the motor windings or bearings are damaged, send them for repair or replace them with new ones.

6.4 Improvement of Power Supply Stability

Stabilize Power Voltage:
- Use a voltage regulator or UPS (Uninterruptible Power Supply) to ensure stable input voltage.
Check Power Line:
- Ensure the power line is in good contact and free from oxidation.

6.5 Control of Environmental Factors

Improve Cooling Conditions:
- Ensure the cooling fans of the drive and motor operate normally to avoid high-temperature environments.
Prevent Moisture and Corrosion:
- In humid or corrosive environments, take protective measures such as sealing the drive cabinet.

7. Preventive Measures for AL-09 Fault

To prevent the occurrence of AL-09 faults, the following measures can be taken:

7.1 Regular Maintenance and Upkeep

Regularly Inspect Mechanical Transmission Components:
- Check the wear and lubrication of gears, guides, screws, and other components.
Regularly Clean Drive and Motor:
- Remove dust and debris to ensure good heat dissipation.
Regularly Check Electrical Connections:
- Ensure all terminal connections are secure and free from oxidation or loosening.

7.2 Parameter Backup and Optimization

Backup Drive Parameters:
- Regularly back up the drive’s parameter settings for quick recovery after faults.
Optimize Parameter Settings:
- Optimize parameters such as gain and torque limit based on actual load and operating conditions.

7.3 Runtime Monitoring and Alarm System

Real-Time Monitoring of Operating Status:
- Use upper-level machines or PLCs to monitor motor current, speed, position, and other parameters in real-time.
Set Alarm Thresholds:
- Set reasonable alarm thresholds in the drive to detect and handle abnormalities promptly.

8. Case Studies

8.1 Case Study 1: AL-09 Fault Caused by Mechanical Jamming

Fault Phenomenon: A CNC machine suddenly stopped during operation, and the drive displayed an AL-09 alarm. Manual rotation of the motor shaft revealed significant jamming in the screw transmission.

Diagnostic Process:

Inspected the mechanical transmission and found that the screw guide lacked lubrication, causing excessive friction.
Checked the drive parameters and found that the torque limit settings were normal.

Solution:

Added lubricating oil to the screw guide.
Adjusted the coupling alignment to reduce radial forces.
Reset the alarm, and the equipment resumed normal operation.

Experience Summary: Mechanical jamming is a common cause of AL-09 faults. Regular maintenance and lubrication of transmission components are crucial.

8.2 Case Study 2: AL-09 Fault Caused by Parameter Setting Errors

Fault Phenomenon: An automated production line frequently displayed AL-09 alarms during debugging, and the motor failed to start normally.

Diagnostic Process:

Inspected the mechanical load and found no abnormalities.
Checked the drive parameters and found that the speed proportional gain ([PE-307]) was set too high, causing system oscillation.

Solution:

Gradually reduced the speed proportional gain until the system stabilized.
Optimized other control parameters, such as the integral time constant ([PE-309]).
Reset the alarm, and the equipment operated normally.

Experience Summary: Parameter setting errors are another significant cause of AL-09 faults. During debugging, parameters should be adjusted gradually to avoid excessive settings.

8.3 Case Study 3: AL-09 Fault Caused by Unstable Power Supply

Fault Phenomenon: A packaging machine suddenly stopped during operation, and the drive displayed an AL-09 alarm. Inspection revealed significant voltage fluctuations in the input power.

Diagnostic Process:

Used a multimeter to measure the input voltage, which fluctuated between 180V and 250V.
Inspected the power line and found poor contact causing excessive voltage drops.

Solution:

Replaced the power line to ensure good contact.
Added a voltage regulator to stabilize the input voltage.
Reset the alarm, and the equipment resumed normal operation.

Experience Summary: Unstable power supply can cause abnormal drive output, triggering overload protection. Ensuring power stability is key to preventing AL-09 faults.

9. Conclusion and Recommendations

AL-09 overload faults are common issues in the LS servo drive APD-VP series in practical applications. Through this analysis, we can draw the following conclusions:

AL-09 faults have diverse causes, including mechanical load abnormalities, electrical parameter setting errors, motor or encoder failures, power supply issues, and environmental factors.
Diagnosing AL-09 faults requires a systematic approach, involving inspections from mechanical, electrical, and environmental perspectives.
Solving AL-09 faults requires targeted measures, such as optimizing mechanical loads, adjusting electrical parameters, maintaining motors and encoders, and stabilizing power supplies.
Preventing AL-09 faults requires proactive measures, including regular maintenance, parameter optimization, and runtime monitoring.

Recommendations:

Establish Equipment Maintenance Records: Document the equipment’s operating status, fault history, and maintenance activities.
Regularly Train Operators: Enhance their ability to diagnose and handle servo drive faults.
Introduce Remote Monitoring Systems: Monitor equipment operating status in real-time to detect and address abnormalities promptly.

Posted on 2025年11月2日2025年11月2日 by baiyuzhan

A Comprehensive Guide to Fault Diagnosis and Troubleshooting for ER.C90 in VEICHI SD700 Servo Drives

Introduction

In the realm of modern industrial automation, servo drives, as the core components of precision control systems, play a pivotal role. The VEICHI SD700 series servo drives are highly regarded for their high performance and reliability, finding widespread applications in fields such as CNC machine tools, robots, printing machinery, and packaging equipment. However, various faults may occur during the use of these products, among which the ER.C90 fault is relatively common, manifesting as encoder communication abnormalities. If not addressed promptly, such faults can not only disrupt production processes but also potentially lead to equipment damage or safety hazards.

Based on the detailed version of the VEICHI SD700 servo system manual and practical engineering experience, this article provides an in-depth analysis of the ER.C90 fault and offers a comprehensive and practical guide for diagnosis and troubleshooting. The aim is to assist engineers and technicians in quickly locating problems and enhancing system stability.

Overview of the SD700 Servo System

The VEICHI SD700 series servo drive is a high-performance AC servo system suitable for 200V and 400V voltage classes, supporting servo motors with power ranges from 100W to 7.5kW. This system employs advanced vector control technology, combined with high-resolution encoder feedback, to achieve closed-loop control, ensuring high precision and high dynamic response of the system.

Main Component Names and Functions of the System

Servo Drive Main Body: Includes a display panel, CHARGE indicator light, and CN series interfaces (such as CN1 control terminals, CN2 encoder interface, and CN7 USB communication terminal). The display panel is used to display status codes, fault codes, and parameter settings.
Servo Motor: Equipped with incremental or absolute encoders, supporting multi-turn absolute position feedback.
Encoder: The core feedback component, typically with a resolution of 17 or 24 bits, used to provide motor position and speed information.
System Block Diagram: The main circuit includes power input, regenerative resistor, and motor output; the control circuit involves PLC upper computers, I/O signals, and communication modules. The SD700 supports multiple communication protocols, such as RS485, CANopen, and EtherCAT, facilitating integration into industrial networks. An example of system composition includes an upper computer (such as a PLC), servo drive, motor, and load, forming a closed-loop control link.

Role of the Encoder in the Servo System

The encoder serves as a bridge connecting mechanical and electrical components, converting the physical motion of the motor into digital signals and providing real-time feedback to the drive. The SD700 servo system mainly uses optical incremental or absolute encoders with resolutions as high as 16,777,216 pulses per revolution (24 bits).

Working Principle of the Encoder

The encoder generates A, B, and Z phase signals (for incremental types) or multi-turn absolute position data (for absolute types) through optical or magnetic grating disks. These signals are transmitted to the drive via the CN2 interface, and the drive calculates the motor position, speed, and torque deviations accordingly to achieve PID closed-loop regulation. If communication is interrupted, the drive cannot obtain accurate feedback, leading to system out-of-control and triggering the ER.C90 fault.

Description of the ER.C90 Fault

The ER.C90 is a specific fault code for the VEICHI SD700 servo drive, displayed on the panel, such as a red LED showing “ER.C90”. This fault is classified as a “Class 1” alarm, meaning “encoder communication fault: disconnection.”

When the drive detects a loss or abnormality in the encoder signal, it immediately stops the motor output and triggers this alarm. Symptoms include:

The motor fails to start or stops suddenly.
The system reports an error and cannot enter the enabled state.
The upper computer monitoring shows zero or abnormal values for position feedback.

Analysis of Fault Causes

The root cause of the ER.C90 fault lies in the interruption of the communication link between the encoder and the drive. The main reasons include:

Signal wire disconnection or poor connection: Cable breakage due to bending, pulling, or aging during use. Loose or oxidized CN2 plugs can also cause poor contact.
Incompatible cable specifications: Using non-original cables or improper shielding layers can lead to signal distortion.
Excessive cable length: Exceeding the recommended length causes significant signal attenuation.
External interference: Electromagnetic interference from devices such as frequency converters and welding machines. Improper shielding grounding exacerbates the problem.
Motor or encoder damage: Failure of the internal photoelectric components of the encoder or wear of the motor bearings leading to unstable signals.
Incorrect parameter settings: Mismatched motor group parameters or incorrect drive power ratings.
Drive hardware failure: Damage to the communication module on the main board.

Diagnostic Steps

Diagnosing the ER.C90 fault requires a systematic approach, starting from simple to complex. Ensure that power is disconnected before operation to avoid the risk of electric shock.

Preliminary Inspection: Observe the panel display to confirm it is an ER.C90 fault. Use the manual FN000 to view the alarm records.
Cable Integrity Test: Use a multimeter to measure each signal wire of the CN2 interface to check for continuity and short circuits.
Connection Inspection: Check the CN2 and motor-end plugs for dust, dirt, or oxidation. Re-plug and test.
Cable Specification Verification: Measure the cable length and confirm that the model matches the requirements in the manual.
Interference Investigation: Check the shielding layer grounding and keep away from interference sources. Try adding magnetic rings for filtering.
Parameter Confirmation: Check parameters such as Pn000 (encoder type) and Pn100 (inertia ratio) for correctness.
Hardware Testing: Replace with spare cables or motors for testing.
Advanced Diagnosis: Connect the CN7 USB and use upper computer software to monitor Un003 (rotor position).

Solutions

Provide specific solutions for each cause:

Disconnection/poor connection: Replace the cable or tighten the plugs.
Incompatible specifications: Select the correct cable model and shorten the length.
Excessive cable length: Optimize the layout to reduce the length.
Interference: Improve grounding and add magnetic rings.
Hardware damage: Replace the encoder or motor.
Parameter errors: Reset the Pn parameters and restore factory settings before reconfiguration.
Drive failure: Contact VEICHI after-sales service to replace the unit.

Preventive Measures

Prevention is better than cure. The following strategies can reduce the incidence of the ER.C90 fault:

Regular maintenance: Check cables and connections every quarter and clean dust.
Environmental optimization: Install in ventilated cabinets to avoid high temperatures. Use EMI filters.
Cable management: Use fixed clips to secure cables and prevent pulling.
Parameter backup: Use the upper computer to export parameters for easy restoration.
Training: Train operators on correct installation to avoid misoperations.
Redundancy design: In critical applications, use dual encoders or wireless feedback.

Case Studies

Case 1: A printing factory using an SD700 servo drive for roller positioning suddenly encountered an ER.C90 fault, and the motor stopped. Diagnosis revealed a broken A-phase wire of the CN2 interface. Replacing the cable and adding a magnetic ring resolved the issue.
Case 2: A factory had a welding machine nearby with poor grounding, causing interference. Adding shielding resolved the ER.C90 fault.

Advanced Debugging Techniques

For stubborn faults, use the upper debugging tools in Chapter 14 of the manual:

Upper computer connection: Connect via the CN7 USB, install the driver, and open the software.
Real-time monitoring: View Un140 bus voltage and Un003 position feedback.
Digital oscilloscope: Capture the encoder signal waveform and analyze distortion.
Auxiliary functions: Perform FN105 vibration initialization and use EASYFFT to eliminate mechanical interference.

Conclusion

Although the ER.C90 fault is common, it can be efficiently resolved through systematic diagnosis and guidance from the manual. The VEICHI SD700 servo system is renowned for its high reliability, and correct maintenance can ensure long-term stable operation. This article provides a comprehensive reference, hoping to be of assistance. For more details, refer to the official manual or contact support.

Posted on 2025年10月31日2025年10月31日 by baiyuzhan

Comprehensive Analysis of the Yaskawa Varispeed F7 PG Feedback Card — A Practical Study on the SI-P1 Ver 3.04

1. Introduction: The Role of the PG Card in Inverter Control Systems

In modern vector-control inverters, the PG card (Pulse Generator card) plays a central role.
It acts as an interface between the inverter and the motor encoder, acquiring high-precision rotational signals from the motor shaft and feeding them back to the inverter’s control CPU.
Through this feedback, the inverter can precisely detect speed, position, and rotational phase, enabling closed-loop vector control, zero-servo holding, stable-speed regulation, and torque compensation.

In Yaskawa’s Varispeed F7 series, the PG feedback card is not just an accessory—it is the core component that transforms the inverter from a standard open-loop V/f device into a high-performance vector drive.
With accurate speed feedback, the F7 achieves servo-level control precision, excellent dynamic response, and high stability even under heavy load variations.

This paper focuses on the SI-P1 Ver 3.04 PG card (code 73600-C0333 / SIP-901), an OEM version widely used in the F7 family.
By comparing it with the official PG-A2/B2/D2/X2 cards described in Yaskawa’s manuals, we analyze its structure, compatibility, wiring method, parameter configuration, and field performance in real industrial applications.

2. Technical Background — Function and Principle of PG Feedback

2.1 Basic Function of the PG Card

The PG card’s primary function is to receive incremental encoder signals (A, B, Z phases) and convert them into the internal pulse format that the inverter’s CPU can process.
Based on these pulses, the inverter continuously calculates the rotational speed, direction, and position deviation of the motor.

This closed-loop feedback enables several advanced control modes:

Speed Feedback Control — maintains a precise target RPM regardless of load fluctuation.
Torque Compensation — improves low-speed torque stability.
Zero-Servo Control — holds the motor shaft at a fixed mechanical position.
Regenerative Braking Control — enhances braking torque using feedback phase information.

The accuracy and signal integrity of the PG card determine the overall response time, torque precision, and stability of the system.

2.2 Common PG Cards Used with the Varispeed F7

Model	Signal Type	Supply Voltage	Typical Application	Remarks
PG-A2	Differential TTL (A/A¯, B/B¯, Z/Z¯)	+5 V	Standard incremental encoders	Most widely used type
PG-B2	Open-collector (single-ended A/B)	+12 V	NPN output encoders	For environments with higher noise
PG-D2	Push-pull (A/B/Z quadrature)	+15 V	Heavy industrial, long-distance feedback	Excellent noise immunity
PG-X2	High-speed TTL differential	+5 V	High-resolution / high-speed vector control	Used in advanced servo applications

All four cards share the same mechanical interface and CN5 connector, but differ in electrical levels and signal types.
Among them, PG-A2 is the standard type used in most F7 applications.

3. Identifying the SI-P1 Ver 3.04 and Its Compatibility

Although the SI-P1 Ver 3.04 is not explicitly listed in the official F7 manual, practical testing and circuit comparison confirm that:

The SI-P1 Ver 3.04 is an OEM-equivalent version of the PG-A2 card.

The justification is as follows:

Identical Signal Architecture
The SI-P1 accepts differential inputs for A, /A, B, /B, Z, /Z, which perfectly matches the TTL line-driver interface of PG-A2.
Same Power Requirements
It provides an internal +5 V DC output (maximum 200 mA) for encoder supply—exactly like the PG-A2—and does not support 12 V or 15 V encoders.
Same Physical Connector
The card plugs directly into the F7 control PCB via the CN5 slot. Pin layout and dimensions are identical to the PG-A2.
Firmware Generation
The “Ver 3.04” label corresponds to the firmware generation period of early-2000s Yaskawa F7 inverters, when PG-A2 was the default model.

Hence, the SI-P1 card can be treated as functionally identical to PG-A2.
All wiring, parameter settings, and diagnostic methods described for PG-A2 apply equally to SI-P1.

4. Detailed Wiring between the SI-P1 and the Encoder

4.1 Terminal Definitions

Pin	Signal Name	Function	Description
1	+5 V	Encoder Power Supply	Provides +5 V DC (≤ 200 mA)
2	0 V	Power Ground	Common reference for encoder
3	A	Phase A positive	Forward rotation signal
4	/A	Phase A negative	Differential complement
5	B	Phase B positive	90° shift from A
6	/B	Phase B negative	Differential complement
7	Z	Zero-mark signal	Once-per-revolution pulse
8	/Z	Zero-mark complement	Optional connection
FG	Frame Ground	Connect to shield of cable

Use twisted-pair shielded cable for each differential pair (A/A¯, B/B¯, Z/Z¯).
Connect the cable shield to FG at the inverter side only.

4.2 Typical Wiring Diagram

Encoder Side               SI-P1 PG Card
+5 V  ───────────────────────→  Pin 1 (+5 V)
0 V   ───────────────────────→  Pin 2 (0 V)
A    ───────────────────────→  Pin 3 (A)
A¯   ───────────────────────→  Pin 4 (/A)
B    ───────────────────────→  Pin 5 (B)
B¯   ───────────────────────→  Pin 6 (/B)
Z    ───────────────────────→  Pin 7 (Z)
Z¯   ───────────────────────→  Pin 8 (/Z)
Shield layer ─────────────→  FG (Ground)

This standard differential connection ensures noise immunity and reliable high-speed feedback, even under strong EMI conditions.

4.3 Electrical Precautions

Keep the encoder cable shorter than 20 m; for longer runs, use a differential line driver (RS-422 standard).
Never connect both ends of the shield to ground—do so only on the inverter side.
Verify the A/B phase shift (90° ± 10°) using an oscilloscope; reversed A/B causes inverted rotation detection.
Avoid running encoder cables in parallel with power cables.

5. Parameter Configuration and Commissioning

To enable the feedback loop, several parameters must be configured in the Varispeed F7:

Parameter	Description	Typical Setting	Notes
A1-02	Control Mode Selection	3	“Vector control with PG”
F1-01	Encoder Pulses per Revolution	e.g., 1024 PPR	Match actual encoder
F1-03	PG Input Type	0	Differential TTL input
E1-04	Rotation Direction Logic	0 or 1	Depends on wiring
U1-05	Monitor Speed Feedback	–	Used for verification

Commissioning Steps

Open-loop Test
Run the inverter without enabling PG feedback. Verify that the motor runs smoothly and direction matches your system.
Enable Closed-Loop Mode
Set A1-02 = 3 and cycle the power. The inverter now reads encoder feedback. Observe that the motor starts softly and maintains constant speed.
Zero-Servo or Position Hold
For applications requiring shaft holding, fine-tune parameters F1-05 to F1-07.
Verification
Check parameter U1-05 to ensure displayed speed matches the actual RPM measured by a tachometer.

6. Practical Field Experience and Case Studies

Case 1: Speed Feedback Optimization

A 37 kW Varispeed F7 inverter driving a conveyor motor used a 1024 PPR encoder.
After replacing a damaged PG-A2 with an SI-P1 Ver 3.04, the system was configured with:

A1-02 = 3
F1-01 = 1024
F1-03 = 0

Result:
Acceleration response improved from 100 ms to 40 ms, and steady-state speed fluctuation dropped below 0.3%.
The SI-P1 performed identically to the original PG-A2.

Case 2: Direction Error due to Reversed Phases

In a hoisting control system, swapping A/B signal pairs caused the inverter to misinterpret rotation direction, leading to oscillation.
After interchanging the A and B channels, feedback direction was corrected, and stability restored.

Case 3: Noise Interference and Shielding

A 15 m unshielded encoder cable caused ±5% speed variation due to EMI.
Replacing it with twisted-pair shielded cable and grounding only at the inverter side reduced fluctuation to ±0.2%.
Proper shielding proved critical for feedback reliability.

7. Signal Verification and Maintenance

Regular inspection of the PG system is essential for long-term stability.

7.1 Oscilloscope Test

Check A/B waveforms at the PG card input:

Duty cycle ≈ 50%
Phase shift ≈ 90°
Distorted or noisy waveforms indicate cable damage or grounding issues.

7.2 Feedback Speed Monitoring

Under no-load constant-speed operation, monitor U1-05.
If speed fluctuates, inspect PG connections, encoder bearings, and connector pins.

7.3 Cleaning and Care

The PG card contains sensitive CMOS components.
Avoid dust or moisture.
Clean contacts periodically with isopropyl alcohol and ensure firm seating in the CN5 slot.

8. Signal Mapping Comparison: SI-P1 vs PG-A2

Function	SI-P1 Pin	PG-A2 Pin	Remark
+5 V Supply	1	1	Encoder Power
0 V Ground	2	2	Common Ground
A Signal	3	3	Differential +
/A Signal	4	4	Differential –
B Signal	5	5	Differential +
/B Signal	6	6	Differential –
Z Signal	7	7	Zero Pulse
/Z Signal	8	8	Complement Zero
FG Shield	FG	FG	Cable Shield Ground

The one-to-one correspondence confirms that SI-P1 can replace PG-A2 without modification.

9. Engineering Discussion and Technical Insights

Functional Equivalence
The SI-P1 Ver 3.04 is a fully compatible PG-A2 card, supporting all F7 feedback control modes including vector, torque, and zero-servo functions.
Signal Quality is Paramount
Differential signal integrity and proper grounding are more critical than parameter tuning.
Incorrect grounding can produce random “PG Loss” or “OV” faults.
Parameter Matching
Always set the correct encoder PPR (F1-01) and direction logic (E1-04) to avoid instability or reverse torque.
Maintenance Importance
Connector oxidation and vibration loosening are common causes of intermittent speed errors.
Regular re-seating of the card ensures reliability.
Cost-Effective Substitution
For legacy F7/G7 systems, the SI-P1 serves as an excellent, low-cost replacement for discontinued PG-A2 cards without any firmware or wiring change.

10. Conclusion

The Yaskawa Varispeed F7 remains one of the most reliable inverter platforms in industrial automation.
As the key interface between the drive and the motor’s feedback device, the PG card is indispensable for achieving high-performance vector control.

Through detailed examination, this study confirms that SI-P1 Ver 3.04 is technically equivalent to the PG-A2 model.
It shares the same wiring, electrical characteristics, and parameter settings.
When properly connected and configured (A1-02 = 3), it enables full closed-loop operation with high accuracy and stability.

For field engineers, understanding this equivalence provides a major advantage—allowing quick replacement, reduced downtime, and seamless integration in maintenance or retrofit projects.

11. Summary of Best Practices

Always use shielded twisted-pair cable, one pair per differential channel.
Ground the shield at one end only (inverter side).
Verify A/B phase direction before enabling closed-loop mode.
Configure feedback parameters carefully according to the encoder specifications.
Periodically check the CN5 slot and card contacts for corrosion or dust.

By following these practices, the SI-P1 PG feedback system can deliver long-term precision and reliability comparable to servo-class control systems.

Author’s Note

This article is written as an original technical analysis for maintenance engineers, automation specialists, and industrial electronics technicians who maintain or retrofit Yaskawa Varispeed F7 inverters.
It integrates both manual specifications and real-world experience gathered from field repairs and performance testing.

Posted on 2025年10月29日2025年10月31日 by baiyuzhan

Technical Analysis and Application of Startup Display Diagnosis from “1.d002” to “00ST” in Leadshine L7 Series Servo Drives

Abstract
The Leadshine L7 series AC servo drives are crucial components in the field of industrial automation. The startup display sequence reflects the device’s initialization status and operational readiness. This paper provides an in-depth analysis of the phenomenon where users observe a brief display of “1.d002” followed by a switch to “00ST,” indicating a normal initialization process. By interpreting the manual, safety precautions, and incorporating online resources from similar EL7 series, it explores the meanings of display codes, diagnostic methods, potential causes, and optimization strategies, aiming to offer comprehensive guidance to engineers and technicians.

Introduction
In modern industrial automation systems, servo drives play a pivotal role. The Leadshine L7 series AC servo drives utilize the latest DSP from Texas Instruments (TI), featuring high integration and reliability. Users often encounter startup display issues, such as the display showing “1.d002” briefly after power-on, followed by a switch to “00ST.” This paper centers on this phenomenon, conducting a systematic analysis by combining excerpts from the user manual and online resources, aiming to assist users in understanding the technical implications of the display sequence and providing practical diagnostic steps.

Servo Drive Fundamentals

Basic Principles

Servo drives drive servo motors to achieve precise motion by receiving command signals from an upper-level controller. The fundamental principles include triple-loop control (position loop, speed loop, and current loop), with PID algorithms at the core.

L7 Series Characteristics

The L7 series belongs to AC servo drives, supporting 220VAC input and a wide power range. The manual emphasizes that improper operation can lead to severe consequences, and users must adhere to safety precautions.

Key Components and Initialization

The key components of a servo system include the drive, motor, and encoder. The drive integrates a DSP processor, and the initialization process involves self-tests, parameter loading, and status monitoring.

Display Panel Basics

The display panel employs a seven-segment LED digital tube, supporting status display, parameter settings, and alarm prompts. Understanding these codes is crucial for diagnosing device status.

Control Modes and Parameter Settings

Servo drives offer control modes including position, speed, and torque modes. Parameter settings are achieved through panel buttons or MotionStudio software.

Safety Guidelines

The manual stresses that product storage and transportation must comply with environmental conditions, and user modifications will void the warranty.

Overview of the L7 Series

Product Features and Updates

The Leadshine L7 series is a fully digital AC servo drive, utilizing TI DSP, supporting stiffness tables, inertia identification, and vibration suppression. The version has evolved from V1.00 to V2.10 with continuous updates.

Application Areas and Manual Structure

The L7 series finds wide applications in PLC control, robotic arms, and other fields. The manual structure covers the preface, safety matters, specifications, installation, wiring, commissioning, and maintenance.

Wiring and Version Descriptions

Wiring includes power, motor, encoder, and I/O ports. The version description indicates program compatibility and content updates.

Display Panel in Detail

Operation Interface and Key Functions

The L7 drive’s operation interface consists of a 6-digit LED digital tube and 5 keys for status display and parameter settings.

Initialization and Monitoring Mode Codes

Upon power-on, the panel first displays initialization codes. “1.d002” may be a custom or transient display, and switching to “00ST” indicates a standby state. Monitoring mode codes include position deviation, motor speed, etc.

Alarm Code Interpretation

Alarm codes start with “Er,” and the absence of “Er” indicates normal operation.

Diagnostic Analysis

Core Phenomenon Interpretation

The display showing “1.d002” briefly followed by a switch to “00ST” is a normal sequence. The initialization process includes self-tests and parameter loading.

Potential Causes Explored

Potential causes include normal boot-up, configuration influences, and external factors.

Diagnostic Steps and Methods

Diagnostic steps include checking the display history, software verification, and factory reset.

Troubleshooting

Non-Normal Situation Exclusion Methods

If non-normal, exclusion methods include power supply checks, wiring verification, parameter resets, and software tuning.

Common Faults and Solutions

Common faults such as overcurrent and overload are unrelated to the display sequence.

Applications and Optimization

Case Studies: CNC Machine Tools and Robotic Arms

Case 1: A CNC machine tool uses the L7 to control axes, and a normal startup sequence ensures precision. Case 2: A robotic arm in bus mode uses EtherCAT synchronization to avoid delays.

Optimization Strategies and Future Trends

Optimization strategies include adjusting control modes and vibration suppression. Future trends involve integrating AI tuning.

Conclusion
The transition from “1.d002” to “00ST” indicates a normal state. Mastering diagnostic methods can enhance application efficiency. It is recommended to refer to the manual and technical support to ensure stable system operation.

Posted on 2025年10月29日2025年10月29日 by baiyuzhan

In-Depth Analysis and Maintenance Practices for Mitsubishi FR-A700 Inverter “E.7” CPU Error

I. Introduction: When the Brain of the Drive Crashes

The Mitsubishi FREQROL-A700 inverter series is renowned for its high-performance vector control, stable communication capabilities, and comprehensive protection functions. It is widely used in CNC machines, plastic molding equipment, air compressors, hoists, and a variety of industrial automation lines.

However, when the display shows “E.7” or “E.CPU”, the inverter immediately halts output, and the entire system comes to a standstill. This is often referred to by technicians as a “brain crash,” as it indicates a critical failure of the inverter’s central processing unit (CPU).

Among all protection codes, E.7 is one of the most severe. It typically signals that internal communication between control units has failed, logic processes have become unstable, or the CPU hardware itself has malfunctioned.
This article offers a comprehensive technical exploration of the E.7 (CPU Error) fault — its causes, diagnostic methods, hardware implications, repair solutions, and preventive measures — supported by real industrial case studies.

II. Understanding the Fault and System Logic

According to the FR-A700 User Manual (page 397):

E.6 / E.7 / E.CPU – CPU Error
When an internal CPU communication error occurs, the inverter stops output.
Inspection Point: Check if there are devices around the inverter that generate strong electrical noise.
Measure: If no external interference is found, contact the supplier or Mitsubishi service center.

This indicates that E.7 is a system-level protection event.
The inverter’s internal logic continuously monitors communication between the main CPU, gate driver interface, and memory/control buses. If any communication timeout or checksum failure occurs, the CPU triggers a protective shutdown to prevent unpredictable IGBT switching or hardware damage.

The main CPU fault logic in the FR-A700 involves:

Abnormal communication between the main processor and gate drive circuits.
Data corruption or response failure in EEPROM, ADC, or communication ICs.
Watchdog timer reset caused by logic hang or power fluctuation.

When the watchdog detects that the CPU fails to respond within its monitoring period, the system declares a “CPU Communication Error” and displays E.7.

III. Technical Causes of the CPU Error

The E.7 fault generally stems from three major categories of issues:

Electromagnetic interference (EMI)
Power supply instability
Internal control board failure

1. Electromagnetic Interference (EMI)

Industrial sites are rich in high-frequency noise sources — welding machines, large contactors, induction heaters, and switching power supplies. These generate voltage spikes and transient electromagnetic waves that couple into the control board’s circuits, disturbing the CPU clock or data bus.

Typical EMI sources include:

Arc welders or high-frequency induction furnaces
Contactors or solenoid valves switching nearby
Control signal lines routed in parallel with power cables
Improper or floating grounding systems

In such cases, E.7 may occur intermittently, often clearing after power cycling — a sign that transient interference is affecting the CPU.

Technical Recommendations:

Separate control wiring from power cables (minimum 10 cm apart).
Use twisted shielded cables for control and communication lines.
Ground all shields at one single point only.
Install proper EMI filters and ferrite cores on input lines.

2. Power Supply Fluctuations or Grounding Issues

The FR-A700 series contains multiple voltage rails — DC bus (≈540 VDC), control voltage (24 VDC), and logic voltage (5 VDC).
When any of these experience transient drops due to unstable input voltage, aging capacitors, or poor grounding, the CPU watchdog may trigger an internal reset, leading to an E.7 CPU Error.

Typical symptoms:

E.7 appears immediately upon power-up
Random alternation between E.6 and E.7
Display flickering or panel freezing

Diagnostic Points:

Measure three-phase input balance and verify stable voltage.
Check DC bus voltage ripple — excessive ripple suggests degraded capacitors.
Measure 24V and 5V supply rails; ensure no drop below tolerance.
Inspect the grounding system — avoid shared return paths with external PLCs or IO devices.

3. Hardware Failure on Control or Power Board

If E.7 persists after confirming stable power and minimal EMI, the most likely cause is a hardware fault.

Common hardware-related sources:

Damaged main CPU (e.g., Renesas or Mitsubishi custom MCU)
Failed EEPROM or memory IC communication
Broken optocouplers (HCPL-2631, etc.) between logic and driver circuits
Poor connection between control board and power board
Feedback interference caused by a shorted IGBT module

Observable signs:

Instant E.7 alarm at power-up
Unable to reset via panel or RES signal
FR-Configurator2 communication fails
No clock signal detected on the CPU oscillator

In this situation, replacing the control PCB or even the entire inverter is often the most efficient solution.

IV. Step-by-Step Diagnostic Procedure

A systematic diagnostic process can help quickly isolate the E.7 cause.

Step 1: Record and Observe

Note when the error occurs (during start, stop, idle, or communication).
Observe whether the fault happens after brief power loss.
Check ambient temperature (CPU overheating can cause instability).

Step 2: Insulation and Ground Testing

After disconnecting power and waiting at least 10 minutes, measure insulation resistance (>5 MΩ) between main terminals and ground.
Ensure no short between control circuits and main circuit.

Step 3: Check for Interference and Grounding Issues

Verify that PE grounding resistance is below 10 Ω.
Ensure all power cables are symmetrical (balanced three-phase).
Avoid “loop grounds” by ensuring star-point grounding topology.
For RS-485 or CC-Link communication, ground the shield at one end only.

Step 4: Monitor Power Rails

Use an oscilloscope to monitor 24V and 5V supplies; ensure minimal ripple (<100 mV).
Confirm the DC bus is steady without oscillation when idle.

Step 5: Module-Level Inspection

Re-seat the operation panel and connectors between boards.
Examine ribbon cables for oxidation or loose pins.
Swap with a known-good control board if available.
If error persists → replace power board or complete drive.

V. Repair and Replacement Strategies

1. Component-Level Control Board Repair

Qualified service technicians can:

Verify CPU clock oscillator output (16–20 MHz typical).
Check watchdog timer pulse (ICs like 74HC123).
Replace EEPROM, voltage regulators, or capacitors.
Re-solder cracked joints and clean carbon residue.
Add low-ESR capacitors (e.g., 47 µF × 2) near CPU power pins to enhance filtering.

2. Inverter Replacement and Parameter Recovery

When the board is irreparable:

Use FR-Configurator2 to back up parameters before removing the unit.
Install the new inverter, then restore parameters via copy function (Pr.990–Pr.999).
Run auto-tuning (Pr.71, Pr.80–Pr.84) to recalibrate motor characteristics.

3. Environmental Hardening

For long-term stability:

Add EMI filters or isolation transformers on input side.
Install surge absorbers (MOVs) between R/S/T lines.
Route control and power cables separately.
Maintain good cabinet ventilation and cleanliness.

VI. Case Study: CPU Error in Injection Molding Machine

An FR-A740-22K-CHT inverter was used as the main drive in a plastic injection molding machine. The unit displayed E.7 intermittently; resetting restored operation temporarily.

Investigation findings:

Three inverters were installed side-by-side in the same panel.
Control signal cables ran parallel to motor leads.
Ground connections were multi-pointed, creating loops.
Heavy dust on control board and fan filter.

Corrective actions:

Re-routed control cables with shielded twisted pairs.
Implemented star-point grounding.
Added 100 µF capacitor to 5V rail on control board for ripple suppression.
Cleaned dust and re-seated connectors.

After these measures, the machine ran for 72 hours continuously without reoccurrence.
Conclusion: E.7 was caused by EMI-induced communication loss rather than true CPU failure.

VII. Relationship Between Related Error Codes

Code	Description	Meaning	Correlation
E.6	CPU Communication Error A	Communication loss in main logic channel	Often co-occurs with E.7
E.7	CPU Communication Error B	Internal bus or logic timing fault	May escalate to E.CPU
E.CPU	CPU Hardware Fault	CPU self-check failure or watchdog timeout	Severe or persistent E.6/E.7

If E.6, E.7, and E.CPU alternate rapidly, it typically indicates either a logic power fault or crystal oscillator failure.

VIII. Preventive Engineering Practices

1. During Electrical Design

Provide dedicated grounding bars (no shared returns).
Use separate grounding cables for each inverter.
Add RC snubber circuits or line filters on power input.
Use crimp terminals for all wiring to prevent loose contacts.

2. During Installation and Commissioning

Test motor insulation before wiring to inverter.
Avoid long, unshielded communication lines.
Use optical isolation modules when interfacing PLCs.

3. During Routine Maintenance

Clean cooling channels and fans every 6 months.
Check fan bearings and noise levels.
Measure DC bus capacitor ESR annually.
Use heaters or dehumidifiers in damp environments.

4. Backup and Record Management

Regularly back up parameters via FR-Configurator2 or PU unit.
After replacing the control board, verify calibration parameters.
For aging units, perform preventive replacement of capacitors and relays.

IX. Technical Insights and Summary

The E.7 fault in the Mitsubishi FR-A700 series is a CPU communication error — a high-level protection mechanism that prevents erratic operation when the internal logic loses synchronization.
It does not relate to mechanical load or overcurrent events, but rather to the integrity of digital control.

Based on field experience, E.7 can be categorized into three scenarios:

Type	Root Cause	Solution
Intermittent	Electrical noise or unstable power	Improve grounding and filtering
Recurrent	Loose connectors, aged components	Maintenance and board cleaning
Persistent	Damaged CPU or control board	Replace control board or full unit

Following the logical troubleshooting flow — external causes → power check → control circuit diagnosis — enables engineers to identify the root problem quickly and avoid unnecessary replacements.

In preventive terms, a robust EMC design and proper grounding layout remain the most effective strategies to eliminate CPU communication errors in high-frequency drive systems.

X. Practical Recommendations

For environments with frequent E.7 errors, consider using a 1:1 isolation transformer (2 kVA or above) for the inverter’s control supply.
In high-temperature cabinets (>45°C), add external forced-air cooling.
For long-distance communication, use optical fiber isolation modules instead of RS-485 copper lines.
For multi-inverter systems, use independent control power supplies for each unit.

Conclusion

The E.7 CPU Error is not simply a nuisance fault — it is an intelligent self-protection feature designed to prevent catastrophic failure in the Mitsubishi FR-A700 inverter series.
Understanding its electrical, logical, and environmental causes allows engineers to perform accurate diagnostics, avoid misjudgment, and reduce downtime.

In today’s automation landscape, where system reliability and electromagnetic compatibility (EMC) are paramount, addressing E.7 is not merely about fixing an error — it’s about building resilience into every layer of the control system.

Posted on 2025年10月28日2025年10月28日 by baiyuzhan

User Guide for EST900 Series Inverter from Yiste: A Comprehensive Analysis from Operation to Troubleshooting

The EST900 series inverter from Yiste, as a high-performance vector inverter, is widely applied in the control and speed regulation of three-phase asynchronous motors. This article, based on the official manual, will elaborate in detail on its operation panel functions, parameter setting methods, external terminal control and speed regulation implementation, as well as handling measures for common fault codes, helping users quickly master the usage skills.

I. Introduction to Operation Panel Functions and Parameter Settings

(A) Overview of Operation Panel Functions

The EST900 series inverter comes standard with an LED operation panel, which offers a variety of functions:

Status Monitoring: It can display key information such as operating frequency, current, voltage, and fault codes in real time.
Parameter Setting: It supports viewing and modifying functional parameters.
Operation Control: Control commands such as start, stop, and forward/reverse rotation can be executed through the panel.
Indicator Lights: It is equipped with indicator lights including RUN (operation), LOCAL/REMOT (control source), FWD/REV (direction), and TUNE/TC (tuning/torque/fault), which visually reflect the equipment status.

(B) Factory Parameter Settings

During debugging or when parameters are in disarray, a factory reset operation can be performed:

Steps:
- Enter the FP – 01 parameter.
- Set it to 1 (restore factory parameters, excluding motor parameters).
- Press the ENTER key to confirm.
- Wait for the display to restore, indicating parameter initialization is complete.
Notes:
- FP – 01 = 2 can clear fault records and other information.
- FP – 01 = 4 can back up the current parameters.
- FP – 01 = 501 can restore the backed-up parameters.

(C) Password Setting and Clearing

To prevent misoperation, a user password can be set:

Setting a Password:
- Enter FP – 00 and set it to a non-zero value (e.g., 1234).
- After exiting, the password needs to be entered when accessing parameters again.
Clearing a Password:
- Set FP – 00 to 0.

(D) Parameter Access Restrictions

Parameter access can be restricted in the following ways:

Parameter Group Display Control:
- Set the FP – 02 parameter to control whether Group A and Group U parameters are displayed.
- For example, setting it to “11” can hide some parameter groups to prevent mismodification.
Prohibition of Modification during Operation:
- Some parameters marked with “★” cannot be modified during operation and need to be set after shutdown.

II. External Terminal Forward/Reverse Rotation Control and Potentiometer Speed Regulation

(A) External Terminal Forward/Reverse Rotation Control

Wiring Terminals:
- D11: Forward rotation (FWD)
- D12: Reverse rotation (REV)
- COM: Digital input common terminal
Parameter Settings:
| Parameter Code | Name | Setting Value | Description |
| —- | —- | —- | —- |
| F0 – 02 | Operation Command Selection | 1 | Terminal control |
| F4 – 00 | D11 Function Selection | 1 | Forward rotation |
| F4 – 01 | D12 Function Selection | 2 | Reverse rotation |
| F4 – 11 | Terminal Command Mode | 0 | Two-wire type 1 |
Note: If a three-wire control system is used, set F4 – 11 = 2 or 3 and cooperate with other DI terminals.

(B) External Potentiometer Speed Regulation

Wiring Terminals:
- +10V: Positive pole of potentiometer power supply
- GND: Negative pole of potentiometer power supply
- A11: Analog voltage input (0 – 10V)
Parameter Settings:
| Parameter Code | Name | Setting Value | Description |
| —- | —- | —- | —- |
| F0 – 03 | Main Frequency Command Selection | 2 | A11 |
| F4 – 13~F4 – 16 | A11 Curve Settings | Adjust according to actual conditions | Minimum/maximum input corresponds to frequency |
Tip: It is recommended that the potentiometer resistance be between 1kΩ and 5kΩ to ensure that the current does not exceed 10mA.

III. Common Fault Codes and Handling Methods

The EST900 series inverter has a comprehensive fault diagnosis function. The following are common faults and their handling methods:

(A) Overcurrent Faults

Fault Code	Name	Possible Causes	Handling Measures
Err02	Acceleration Overcurrent	Motor short circuit, too short acceleration time	Check motor insulation, increase acceleration time
Err03	Deceleration Overcurrent	Short deceleration time, large load inertia	Increase deceleration time, install a braking resistor
Err04	Constant-speed Overcurrent	Load mutation, mismatched motor parameters	Check the load, perform motor tuning again

(B) Overvoltage Faults

Fault Code	Name	Possible Causes	Handling Measures
Err05	Acceleration Overvoltage	High input voltage, external force during acceleration	Check power supply voltage, enable overvoltage suppression
Err06	Deceleration Overvoltage	Short deceleration time, energy feedback	Increase deceleration time, install a braking unit
Err07	Constant-speed Overvoltage	External force dragging during operation	Check the mechanical system, enable overvoltage suppression

(C) Other Common Faults

Fault Code	Name	Possible Causes	Handling Measures
Err09	Undervoltage Fault	Low power supply voltage, rectifier bridge fault	Check the power supply, measure the bus voltage
Err10	Inverter Overload	Excessive load, undersized selection	Check the load, replace with a higher-power inverter
Err11	Motor Overload	Excessive motor load, improper protection parameter setting	Adjust the F9 – 01 motor overload gain
Err14	Module Overheating	Poor heat dissipation, fan fault	Clean the air duct, replace the fan
Err16	Communication Fault	Wiring error, improper parameter setting	Check the communication line, set FD group parameters

(D) Fault Reset Methods

Press the STOP/RESET key on the panel.
Set a DI terminal to the “Fault Reset” function (F4 – xx = 9).
Write “2000H = 7” through communication.
Power off and restart (wait for more than 10 minutes).

IV. Conclusion

The Yiste EST900 series inverter is powerful and flexible in operation, capable of adapting to various industrial scenarios. Through the introduction in this article, users can master the following key contents:

Basic usage methods of the operation panel and parameter setting skills.
How to control and regulate the speed of the motor using external terminals and a potentiometer.
Diagnostic ideas and handling skills for common faults.
Effective use of password management and parameter protection mechanisms.
During actual use, it is recommended that users strictly follow the manual specifications for wiring and parameter setting, and regularly carry out maintenance work to ensure the long-term stable operation of the equipment.

Posted on 2025年10月26日2025年10月28日 by baiyuzhan

In-Depth Analysis and Troubleshooting of Emerson EV2000 Inverter P.oFF Fault

1. Introduction

In industrial automation systems, frequency inverters are the key components for controlling motor speed and torque. The operational stability of an inverter directly determines the reliability of an entire production line. Among numerous industrial drive products, the Emerson EV2000 series is well recognized for its robust performance, precise vector control, and adaptability to a wide range of applications — from pumps and fans to textile machines and conveyors.

However, during field operation or long-term use, some users may encounter a display message reading “P.oFF” on the inverter’s LED panel.
At first glance, this may look like a severe fault such as a power module failure or control board defect.
In reality, “P.oFF” is not a typical fault alarm, but rather a protective shutdown state known as “Undervoltage Lockout (LU).”

This article provides a comprehensive technical analysis of the P.oFF condition in the Emerson EV2000 inverter.
It integrates official documentation, field diagnostic data, and maintenance experience to explain its causes, triggering mechanism, troubleshooting methods, and preventive measures.

2. Technical Definition of P.oFF

According to the official EV2000 User Manual:

“When the DC bus voltage drops below the undervoltage threshold, the inverter outputs a protection signal and displays ‘P.oFF’ on the LED panel.”

This statement reveals the essence of the fault:
P.oFF occurs when the inverter’s internal DC bus voltage (DC link voltage) falls below a safe limit.

Normally, the rectifier circuit inside the EV2000 converts three-phase AC power (380V ±10%) into DC voltage of approximately 540–620 VDC.
When the input power drops, the rectifier is damaged, the DC bus capacitors age, or the braking unit malfunctions, the DC voltage may fall below the predefined undervoltage threshold (around 300 VDC).
At that point, the inverter automatically enters a protective lockout to prevent unstable operation or component damage.

It is important to note that unlike “E” code faults (such as E001 – overcurrent, E002 – overvoltage), P.oFF does not trigger a trip alarm.
Instead, the inverter temporarily disables output until the voltage returns to normal.

3. Electrical Mechanism Behind the P.oFF State

To fully understand this phenomenon, we must look into the EV2000’s main power structure.

3.1 Composition of the Main Circuit

The inverter’s main power path includes the following key components:

Input terminals (R, S, T): three-phase AC supply
Rectifier bridge module: converts AC to DC
DC bus capacitors: stabilize and filter DC voltage
Braking unit and resistor: absorb regenerative energy from motor deceleration
IGBT inverter bridge: converts DC back into PWM-controlled AC output

3.2 How Undervoltage Lockout Is Triggered

The control board constantly monitors the DC bus voltage.
When it detects a voltage lower than the threshold (typically around 300–320 VDC), it executes the following logic sequence:

Disables IGBT outputs — halting motor operation
Displays “P.oFF” on the panel
Waits in standby mode until the DC bus recovers above the normal level (typically >380 VDC)

This mechanism is a preventive protection system designed to shield the inverter from grid voltage sags, capacitor discharges, or transient faults.
Thus, P.oFF is not an error; it is an intentional safety lock.

4. Root Causes of the P.oFF Condition

From field experience and manual analysis, the following are the most common reasons for P.oFF to appear.

(1) Input Power Problems

Voltage imbalance between the three input phases (>3%)
Mains voltage below 320V AC or fluctuating severely
Loose power terminals or poor contact
Excessive line voltage drop due to long cable runs

These account for nearly half of all P.oFF cases and are primarily related to unstable supply power.

(2) Faulty Rectifier Module

A damaged or open diode inside the rectifier bridge reduces the DC bus voltage, often accompanied by audible hum or irregular current flow.

(3) Aged or Leaky DC Capacitors

Over time, electrolytic capacitors lose capacitance and their internal ESR increases.
This weakens their ability to smooth the DC voltage, resulting in a temporary drop when load or braking energy fluctuates — enough to trigger an undervoltage lock.

In units running for 3–5 years, this is one of the most frequent root causes.

(4) Braking Circuit Malfunction

A shorted braking unit or resistor constantly discharges the DC bus, causing the voltage to collapse.
To verify, disconnect the braking circuit and power on again — if P.oFF disappears, the issue lies in that circuit.

(5) Momentary Power Interruptions

Factories with welding machines, compressors, or heavy inductive loads can experience grid sags.
If the inverter’s “Ride-through” (instantaneous power-loss recovery) function is disabled, any short voltage dip may cause P.oFF.

5. Systematic Troubleshooting Process

To effectively diagnose and repair the P.oFF issue, engineers can follow a step-by-step workflow:

Step 1 – Observe the Symptom

Panel displays “P.oFF”
No “E” fault code is present
Motor stops automatically
After a few minutes, the inverter may restart on its own

If these conditions match, the inverter is in undervoltage lockout mode.

Step 2 – Measure Input Power

Use a multimeter to measure R–S–T line voltages:

Normal range: 380–440 V
Below 360 V or phase difference >10 V → adjust power source or connections

Step 3 – Measure DC Bus Voltage

Check voltage across (+) and (–) terminals:

Normal: 540–620 VDC
Below 300 VDC → rectifier or capacitor failure

Step 4 – Isolate the Braking Circuit

Disconnect the braking resistor/unit and test again.
If the problem disappears, replace or repair the braking components.

Step 5 – Test the DC Capacitors

After power-off, measure capacitance and discharge rate:

If voltage drops to zero within a few seconds, leakage is severe
Replace if measured capacitance is <70% of rated value

Step 6 – Verify Control Power

Check auxiliary voltages (P24, +10V, +5V).
Low control supply may cause false P.oFF detection.

6. Repair and Recovery Procedures

Once the root cause has been identified, proceed with the following repair actions:

Stabilize Power Supply
- Re-tighten input terminals
- Ensure voltage balance across all three phases
- Install an AC reactor or voltage stabilizer if necessary
Replace Faulty Components
- Replace aged electrolytic capacitors as a set
- Replace damaged rectifier modules with same-rated units
Inspect Braking Circuit
- Measure P–PR resistance for shorts
- Ensure thermal relay contacts (TH1, TH2) are functioning
Enable Ride-through Function
The EV2000 allows short-duration undervoltage ride-through; enabling this can prevent false P.oFF triggers caused by brief voltage dips.
Recommission and Verify
- Power up and observe DC voltage stability
- Run at light load for 10 minutes, then gradually increase load
- Once the display shows “RDY”, the inverter is ready for normal operation

7. Preventive and Optimization Measures

To avoid recurring undervoltage lockouts, adopt the following best practices:

7.1 Power-Side Protection

Use proper circuit breakers or fuses rated for inverter service
Add a DC reactor for harmonic suppression and voltage stabilization
Use thicker power cables if installation distance is long

7.2 Environmental Control

Maintain cabinet temperature below 40°C
Ensure clean airflow; avoid dust, oil, or moisture buildup
Regularly clean cooling fans and filters

7.3 Periodic Maintenance

Measure DC bus voltage and capacitor health yearly
Replace capacitors after ~3 years of continuous operation
Test rectifier module every 5 years or after heavy load operation

7.4 Parameter Optimization

Set appropriate acceleration/deceleration times to avoid current spikes
Enable AVR (Automatic Voltage Regulation) and Current Limit functions
Review output terminal settings in parameter group F7 to prevent incorrect logic assignments

8. Case Study: Intermittent P.oFF on a 22kW Fan Drive

Background:
A 22kW EV2000 inverter controlling a centrifugal fan exhibited intermittent P.oFF shutdowns after six months of operation.

Symptoms:

Occurred around 45 Hz operation
The inverter automatically recovered after a few minutes
Mains voltage appeared normal

Diagnosis:

DC bus voltage fluctuated between 520–550V with periodic dips
Two electrolytic capacitors found bulging and degraded
Replaced capacitors → inverter operated normally

Conclusion:
The failure was caused by aged capacitors reducing DC storage capacity, resulting in transient undervoltage.
This is a classic “aging-induced P.oFF” scenario.

9. Conclusion

The P.oFF message on Emerson EV2000 inverters is not a random or critical failure, but a designed protective feature to safeguard the drive system when DC bus voltage drops abnormally.

Understanding its mechanism helps engineers correctly differentiate between true hardware faults and temporary protective lockouts.
By following a structured diagnostic approach — from input power verification to capacitor and braking circuit inspection — technicians can quickly restore normal operation.

Furthermore, implementing preventive maintenance and enabling built-in functions such as ride-through and AVR can significantly enhance long-term reliability.

As the design philosophy of Emerson EV2000 suggests:

“Reliability is not accidental — it begins with every small detail of protection.”

Posted on 2025年10月25日2025年10月26日 by baiyuzhan

🔧 Chmairss VGS30A Air Compressor — VEMC Inverter “Err14” Fault Analysis and Repair Guide

From Overheated IGBT Modules to Full System Recovery

1. Introduction

In modern screw air compressors, the variable frequency drive (VFD) is the core component responsible for controlling motor speed and optimizing power consumption.
The Chmairss VGS30A compressor, equipped with a 22 kW VEMC inverter, uses variable-speed control to maintain constant discharge pressure while achieving high energy efficiency.

However, after long-term operation, one of the most common issues that field engineers encounter is the “Err14 – Module Overheat” fault on the VEMC inverter.
This error not only causes system shutdown but also indicates potential thermal imbalance or hardware degradation inside the inverter.

This article provides a comprehensive technical explanation and a complete repair workflow — from understanding the root cause of Err14, diagnosing the issue step-by-step, to repairing and preventing future failures. It is based on real-world field data from a VGS30A compressor maintenance case.

2. Fault Symptoms and Display Information

(1) On the Main Control Panel (HMI)

The compressor controller repeatedly shows the following message:

STATE: MOTOR INV FAULT
CODE: 00014

Multiple entries appear in the fault history list (024–028), all labeled “MOTOR INV FAULT.”

(2) On the VEMC Inverter Panel

The inverter LED display reads:

Err14

The red alarm indicator is on, and the motor cannot start.
Once the contactor closes, the inverter trips immediately.

(3) PLC and System Reaction

The PLC detects the inverter fault signal and sends a stop command to the entire compressor.
Frequency display freezes at 0.0 Hz, power output shows 0.0 kW, and total run time stops accumulating.

3. Understanding the “Err14” Code — Module Overheat Fault

According to VEMC documentation:

Err14 = Module Overheat Fault (IGBT Overtemperature)

The inverter continuously monitors the IGBT module temperature via an NTC thermistor attached to the power module.
This analog signal is converted to a voltage and fed to the control CPU through an A/D converter.

Normal temperature range: 25 °C – 75 °C
Warning level: ~85 °C
Trip threshold: ~95 °C

If the module temperature exceeds the limit or the temperature signal becomes abnormal (open circuit, short circuit, or unrealistic value), the inverter will immediately shut down to protect the IGBT module. The control CPU disables PWM output and reports Err14.

4. Common Root Causes of Err14

Based on maintenance experience and field diagnostics, there are five main categories of causes for Err14:

Category	Cause	Description
🌀 Cooling failure	Fan blocked or not running	Dust, oil mist, or worn bearings stop the fan, reducing heat dissipation efficiency.
🌡️ Ambient overheating	Poor cabinet ventilation	When internal cabinet temperature exceeds 45 °C, the module’s junction temperature rises quickly.
🔌 NTC thermistor fault	Broken, oxidized, or loose sensor	The temperature signal becomes unstable or reads as “overheated” even at normal temperature.
⚡ IGBT module damage	Aging or partial short circuit	Localized overheating triggers overtemperature alarm even under light load.
🧭 Control board error	Faulty sampling or amplifier circuit	A/D converter malfunction misreads temperature as extreme value, causing false alarm.

5. Step-by-Step Diagnostic Procedure

Step 1 – Inspect the Cooling Fan and Air Duct

Power on the inverter and check whether the internal cooling fan starts automatically.
If the fan does not spin, measure the voltage at the fan terminals (usually DC 12 V or DC 24 V).
- Voltage present but fan not spinning → fan motor failure.
- No voltage → main control board output failure.
Clean the air duct, dust filter, and heat-sink fins thoroughly.

Step 2 – Check Cabinet Temperature

Use an infrared thermometer to measure temperature inside the control cabinet.
If it exceeds 45 °C, install additional exhaust fans or ventilation openings.
Avoid placing the cabinet near heat sources (e.g., compressor discharge pipe).

Step 3 – Test the NTC Thermistor

Power off and wait at least 10 minutes for discharge.
Remove the drive or power board.
Measure resistance between NTC terminals (typically around 10 kΩ at 25 °C).
Heat the sensor slightly with a hot-air gun — the resistance should decrease with rising temperature.
If resistance is fixed or open circuit → replace the thermistor.

Step 4 – Check the IGBT Power Module

Use a multimeter diode-test function to check each phase (U, V, W) to positive/negative bus.
Any shorted or low-resistance reading (< 0.3 Ω) indicates IGBT damage.
Verify that the power module is tightly clamped to the heat sink.
Reapply high-quality thermal grease (e.g., Dow Corning 340) if dried or cracked.

Step 5 – Check the Control Board Temperature Circuit

If all above components are normal but Err14 remains:

Inspect connector pins (often CN6 or CN8) for oxidation or loose contact.
Use an oscilloscope to observe temperature signal voltage (should decrease gradually as temperature rises).
Constant 0 V or 5 V output → indicates A/D converter or amplifier failure.
Replace the entire driver/control board if signal circuit is defective.

6. Case Study — Actual Field Repair of a VGS30A Compressor

Equipment details:

Model: Chmairss VGS30A
Inverter: VEMC 22 kW
Total runtime: 7 303 hours
Ambient temperature: ~38 °C
Fault: Err14 appears within seconds after startup; fan not rotating

Inspection and Findings

Component	Result	Action Taken
Cooling fan power	24 V output normal	Fan motor seized → replaced
Air duct	Heavy dust accumulation	Cleaned thoroughly
Thermistor	9.7 kΩ at 25 °C	OK
IGBT module	All phases normal	OK
Thermal grease	Completely dried	Reapplied new grease
Control board	No oxidation or damage	OK

After cleaning and replacing the fan, the inverter started normally.
After 30 minutes of continuous operation, module temperature stabilized at 58 °C, confirming successful repair.

7. Electrical and Thermal Theory Behind Err14

(1) Power Loss and Junction Temperature

The IGBT’s heat generation consists of conduction and switching losses:
[
P_{loss} = V_{CE} \times I_C + \tfrac{1}{2}V_{CE} I_C f_{sw} (t_{on}+t_{off})
]
If heat cannot be transferred efficiently to the heat sink, junction temperature (Tj) rises sharply, increasing conduction loss — a positive feedback that can lead to thermal runaway and module destruction.

(2) Importance of Thermal Interface

The thermal resistance (Rθjc) between IGBT and heat sink determines how quickly heat is removed.
Dried or aged thermal compound increases resistance several times, leading to localized hot spots even when load current is normal.

(3) Protection Logic Inside VEMC Drive

The inverter CPU continuously samples the temperature signal:

Below 0.45 V (≈ 95 °C): trigger Err14 and shut down PWM output.
Above 0.55 V (≈ 85 °C): allow reset condition.
Open circuit: immediate fault lockout, manual reset required.

8. Preventive Maintenance Recommendations

Task	Frequency	Recommended Action
Clean cooling fan and duct	Every 3 months	Use compressed air to remove dust and oil residue.
Replace thermal grease	Every 12 months	Apply fresh silicone-based compound between IGBT and heat sink.
Check ambient temperature	Continuous	Ensure cabinet stays below 40 °C.
Tighten wiring terminals	Every 6 months	Prevent loose or oxidized connections.
Record temperature log	Each service	Document operating temperature trend.
Inspect power module	Upon abnormal fault	Use thermal camera to detect uneven heating.

Regular maintenance can extend inverter lifetime by 30–50 %, reduce downtime, and prevent expensive module failures.

9. Temporary Reset for Diagnostic Verification

If you suspect a false alarm:

Power off and wait at least 10 minutes for cooling.
Power on and press STOP/RESET.
If Err14 reappears immediately → likely sensor or circuit fault.
If it occurs after several minutes of operation → genuine overheating issue.

10. Troubleshooting Flow (Text Version)

Err14 Detected →
   ↓
Check Cooling Fan Running?
   ├─ No → Measure fan supply → replace fan if needed
   └─ Yes →
         ↓
Is Ambient Temperature >45°C?
         ├─ Yes → Improve ventilation
         └─ No →
               ↓
Measure NTC Thermistor Resistance
               ├─ Abnormal → Replace NTC
               └─ Normal →
                     ↓
Inspect IGBT Module & Thermal Grease
                     ├─ Abnormal → Reapply grease / replace module
                     └─ Normal →
                           ↓
Replace Driver Board (temperature circuit failure)

11. Practical Notes and Safety Reminders

Always discharge DC bus capacitors before touching power terminals (wait >10 minutes).
When replacing thermal grease, ensure no air gaps between module and heat sink.
If replacing the IGBT module, apply torque evenly and use original insulation pads.
Keep cabinet filters clean and avoid placing the compressor near exhaust heat or walls.
Use infrared thermometer to monitor heat sink temperature during first startup after repair.

12. Lessons Learned

This case of the Chmairss VGS30A compressor with VEMC inverter Err14 demonstrates the critical role of thermal management in power electronics.
Although the message “Module Overheat” seems simple, it reflects a complex interaction between cooling airflow, thermal interface condition, and signal detection circuits.

Field statistics show:

About 70 % of Err14 faults are resolved by cleaning the cooling path, replacing fans, or re-greasing the module.
The remaining 30 % involve circuit faults or component failures (NTC or driver board).

Understanding these mechanisms allows engineers to diagnose quickly, repair efficiently, and reduce costly downtime.

13. Conclusion

The Err14 (Module Overheat) fault is not merely an alarm — it is the inverter’s self-protection mechanism preventing irreversible IGBT damage.
Proper analysis requires both electrical and thermal reasoning.
By following the structured diagnostic steps in this guide — inspecting the fan, air duct, thermistor, power module, and control board — maintenance engineers can isolate the root cause systematically.

Regular preventive maintenance, good ventilation, and periodic internal cleaning are the best strategies to ensure long-term reliability of VEMC inverters in air compressor applications.

Posted on 2025年10月19日2025年10月19日 by baiyuzhan

DOVOL DV950E Permanent Magnet Synchronous Frequency Converter User Guide

I. Product Overview

The DOVOL DV950E series permanent magnet synchronous frequency converter is a general-purpose, high-performance current vector frequency converter. It is mainly used to control and adjust the speed and torque of three-phase AC synchronous motors. This guide provides detailed information on the converter’s functional features, operation methods, parameter settings, and troubleshooting, helping users quickly master the skills of using the equipment.

II. Basic Functions and Wiring

Product Main Features

Control Modes: Supports sensorless vector control (SVC), sensor-based vector control (FVC), and V/F control.
Frequency Range: 0 – 500Hz.
Overload Capacity: 150% of the rated current for 60 seconds, 180% of the rated current for 3 seconds.
Speed Regulation Range: 1:50 in SVC mode, 1:1000 in FVC mode.
Built-in PID Regulator: Supports process closed-loop control.
Multiple Communication Protocols Supported: Modbus, ProfiBus-DP, CANlink, CANopen.

Electrical Installation Precautions

Main Circuit Wiring: Correctly distinguish between input terminals (R, S, T) and output terminals (U, V, W).
Braking Resistor: Do not connect the braking resistor directly between the DC bus (+) and (-) terminals.
Motor Cable Length: When the motor cable length exceeds 100m, install an AC output reactor.
Grounding: Ensure reliable grounding with a grounding wire resistance of less than 10Ω.
Power Supply Voltage: Before powering on, ensure that the power supply voltage matches the rated voltage of the frequency converter.

III. Operation Panel Usage

Panel Layout and Indicators

RUN: Running status indicator (lights up when in operation).
LOCAL/REMOT: Control mode indicator (off – panel control; on – terminal control; flashing – communication control).
FWD/REV: Forward/reverse rotation indicator (lights up for reverse rotation).
TUNE/TC: Tuning/torque control/fault indicator.
Five-digit LED Digital Display Area.
Function Keys: PRG (programming), ENTER (confirmation), ▲▼ (increase/decrease), ◄ (shift), etc.

Basic Operation Process

Enter the parameter setting mode by pressing the PRG key.
Select the function group using the ▲▼ keys.
Press ENTER to enter the specific parameter setting.
After modifying the parameter value, press ENTER to save it.
Press the PRG key to return to the previous menu.

IV. Core Function Implementation Methods

Motor Forward/Reverse Rotation Control

Method 1: Panel Control

Set P0-02 = 0 (panel command channel).
Set the running direction via P0-09 (0 – same direction; 1 – opposite direction).
Press the RUN key to start and the STOP key to stop.

Method 2: Terminal Control

Set P0-02 = 1 (terminal command channel).
Assign DI terminal functions: P4-00 = 1 (DI1 for forward rotation), P4-01 = 2 (DI2 for reverse rotation).
Control the on/off state of the DI terminals through external switches to achieve forward/reverse rotation.

Method 3: Communication Control

Set P0-02 = 2 (communication command channel).
Send forward/reverse rotation commands through communication (requires a communication card).
Note: To disable reverse rotation, set P8-13 = 1.

Frequency Regulation Methods

Digital Frequency Setting

Set P0-03 = 0 or 1 (digital setting).
Set the preset frequency via P0-08.
During operation, fine-tune the frequency using the panel ▲▼ keys or UP/DOWN terminals.

Analog Frequency Setting

Set P0-03 = 2 (AI1)/3 (AI2)/4 (AI3).
Configure the curve characteristics of the corresponding AI input (P4-13 – P4-27).
Adjust the frequency using an external potentiometer or PLC analog output.

Multi-speed Control

Set P0-03 = 6 (multi-speed instruction).
Assign DI terminals as multi-speed instructions (P4-00 – P4-09 = 12 – 15).
Set the frequency values for each speed segment in the PC group (PC-00 – PC-15).

PID Frequency Regulation

Set P0-03 = 8 (PID).
Configure the PID parameters in the PA group.
Automatically adjust the frequency based on the feedback signal.

Motor Parameter Tuning

No-load Tuning Steps

Ensure that the motor is mechanically decoupled from the load.
Correctly input the motor nameplate parameters (P1-01 – P1-05).
Set P1-37 = 12 (synchronous motor no-load tuning).
Press the RUN key to start tuning (approximately 2 minutes).
The parameters are automatically saved after tuning is completed.

Loaded Tuning Steps

Set P1-37 = 11 (synchronous motor loaded tuning).
Press the RUN key to start tuning.
The parameters are automatically saved after tuning is completed.

Note: Loaded tuning cannot obtain the back electromotive force coefficient, and the control accuracy is slightly lower than that of no-load tuning.

V. Advanced Function Configuration

Frequency Sweeping Function (Textile Applications)

Set PB-00 = 0 (relative to the center frequency) or 1 (relative to the maximum frequency).
Set PB-01 (frequency sweeping amplitude), PB-02 (jump amplitude).
Set PB-03 (frequency sweeping period), PB-04 (triangular wave rise time).
Control the frequency sweeping pause through the DI terminal (P4-xx = 24).

Fixed-length Control

Set DI5 function as length counting input (P4-04 = 27).
Set PB-07 (pulses per meter).
Set PB-05 (preset length).
Assign DO terminals as length arrival signals (P5-xx = 10).

Counting Function

Set DI terminals as counting input (P4-xx = 25) and reset (P4-xx = 26).
Set PB-08 (preset count value), PB-09 (specified count value).
Assign DO terminals as counting arrival signals (P5-xx = 8 or 9).

Timing Control

Set P8-42 = 1 (timing function enabled).
Set P8-44 (timing operation time) or select AI input via P8-43.
The equipment automatically stops after reaching the preset time.

VI. Fault Diagnosis and Handling

Common Fault Codes and Handling

Fault Code	Fault Type	Possible Causes	Handling Methods
Err02	Acceleration Overcurrent	Short acceleration time/heavy load	Extend the acceleration time P0-17/check the mechanical load
Err03	Deceleration Overcurrent	Short deceleration time	Extend the deceleration time P0-18
Err04	Constant-speed Overcurrent	Load突变 (Load mutation)/motor short circuit	Check the motor insulation/adjust the torque limit P2-10
Err09	Undervoltage	Low input voltage/power outage	Check the power supply voltage/set P9-59 for instantaneous power failure without stop
Err11	Motor Overload	Heavy load/undersized motor	Reduce the load/check the rated current setting P1-03
Err14	Module Overheating	High ambient temperature/poor heat dissipation	Improve the heat dissipation conditions/reduce the carrier frequency P0-15
Err20	Encoder Fault	Signal interference/wiring error	Check the encoder wiring/set P2-32 = 0 to disable Z correction

Fault Reset Methods

Panel Reset: Press the STOP/RES key in the fault state.
Terminal Reset: Set the DI terminal function to 9 (fault reset).
Communication Reset: Send a reset command through communication.

Fault Record Inquiry

Recent Fault: Check P9-16 – P9-22.
Second Fault: Check P9-27 – P9-34.
First Fault: Check P9-37 – P9-44.

VII. Maintenance and Upkeep

Daily Inspection

Check if the cooling fan is operating normally.
Check for loose wiring terminals.
Check if the enclosure temperature is abnormal.
Regularly remove dust from the radiator.

Regular Maintenance

Check the appearance of electrolytic capacitors every six months.
Check the insulation resistance annually (measure after powering off).
Replace the cooling fan every 2 years (depending on the operating environment).

Parameter Backup

Set PP-01 = 4 (backup user parameters).
To restore, set PP-01 = 501.
Restore to factory settings: PP-01 = 1.

VIII. Safety Precautions

Do not open the cover when powered on. After powering off, wait for 10 minutes before performing wiring operations.
Do not connect the braking resistor directly to the DC bus.
Perform an insulation check on the motor before the first use (≥5MΩ).
Derate the equipment when the altitude exceeds 1000m (derate by 1% for every 100m).
Derate the equipment when the ambient temperature exceeds 40℃ (derate by 1.5% for every 1℃).
Do not install capacitors or surge suppressors on the output side of the frequency converter.

This guide provides a detailed introduction to the various function implementation methods of the DV950E frequency converter. When using it in practice, please select the appropriate configuration method according to the specific application scenario. For complex application scenarios, it is recommended to contact the manufacturer’s technical support for more professional guidance.

Posted on 2025年10月17日2025年10月17日 by baiyuzhan

User Manual and Operation Guide for Huli Xichuan XC-5000 Series Frequency Converters

I. Operation Panel Functions and Basic Settings

1.1 Introduction to Operation Panel Functions

The operation panel of the XC-5000 series frequency converters adopts a three-level menu structure, with the main functional components including:

LED Display Area:

5-digit LED Digital Tube: Displays set frequency, output frequency, monitoring data, and alarm codes.

Function Indicator Lights:

RUN: Indicates the running status.
LOCAL/REMOT: Indicates the control mode (panel/terminal/communication).
FWD/REV: Indicates forward/reverse rotation.
TUNE/TC: Indicates tuning/torque control/fault status.

Key Functions:

Programming Key (PRG): Enters/exits the first-level menu.
Confirm Key (ENTER): Enters menus/confirms parameters.
Increment/Decrement Keys (▲/▼): Increases/decreases data.
Shift Key (◄): Selects display parameters/modification positions.
Run Key (RUN): Controls keyboard operation.
Stop/Reset Key (STOP/RES): Stops operation/resets faults.
Multi-Function Selection Key (MF.K): Defines functions according to F7-01.

1.2 Parameter Initialization Settings

Restore Factory Parameters (excluding motor parameters):

Set FP-01 = 1 and confirm.

Clear Operation Record Information:

Set FP-01 = 2 and confirm.

Restore User Backup Parameters:

Set FP-01 = 501 and confirm.

Notes:

Initialization operations must be performed in the stop state.
After initialization, running parameters need to be reset.
In vector control mode, motor parameter identification needs to be redone.

1.3 Password Setting and Management

Setting a Password:

Enter the function code FP-00 and set a 4-digit numerical password (1-65535), then confirm.

Password Protection Activation:

Password protection takes effect after exiting the function code editing state.

Canceling Password Protection:

Use the password to enter parameter settings and set FP-00 to 0, then confirm.

1.4 Parameter Access Restriction Settings

Function Group Display Control (FP-02):

Units digit: U group display selection.
Tens digit: A group display selection.

Personalized Parameter Group Display Control (FP-03):

Units digit: User-defined parameter group display selection.
Tens digit: User-modified parameter group display selection.

Function Code Modification Attribute (FP-04):

Sets whether parameters can be modified (0 for modifiable/1 for non-modifiable).

Manufacturer Parameter Protection:

Parameters marked with “*” are prohibited from being modified by users.

II. External Terminal Control and Speed Adjustment Settings

2.1 External Terminal Forward/Reverse Rotation Control

Hardware Wiring:

Control power wiring: +24V-COM provides +24V power.
Control signal wiring (two-wire control):
- DI1-COM: Forward rotation signal input.
- DI2-COM: Reverse rotation signal input.

Parameter Settings:

Command source selection: F0-02 = 1.
Terminal function definition: F4-00 = 1 (DI1 for forward rotation), F4-01 = 2 (DI2 for reverse rotation).
Terminal command mode: F4-11 = 0.
Reverse rotation control enable: F8-13 = 0.

2.2 External Potentiometer Speed Adjustment Settings

Hardware Wiring:

Connect the two ends of the potentiometer to +10V and GND, and connect the sliding end to AI1-GND.
Recommended potentiometer specifications: Resistance 1kΩ-5kΩ, power 0.5W or above.

Parameter Settings:

Frequency source selection: F0-03 = 2.
AI curve settings: F4-13 = 0.00V, F4-14 = 0.0%, F4-15 = 10.00V, F4-16 = 100.0%.
Frequency range limitation: F0-10 = 50.00Hz, F0-12 = 50.00Hz, F0-14 = 0.00Hz.

III. Fault Diagnosis and Handling

3.1 Common Fault Codes and Solutions

Fault Code	Fault Type	Possible Causes	Solutions
ERR02	Acceleration Overcurrent	Load mutation, short acceleration time	Check the load, increase the acceleration time F0-17
ERR03	Deceleration Overcurrent	Short deceleration time, large load inertia	Increase the deceleration time F0-18, install a braking resistor
…	…	…	…
ERR20	Encoder Fault	PG card fault, wiring error	Check the encoder wiring, set the F1-36 detection time

3.2 Fault Information Query and Reset

Fault History Query:

F9-14 to F9-16: Record the types of the last three faults.
F9-17 to F9-46: Record the operating status parameters at the time of the fault.

Fault Reset Methods:

Panel reset: Press the STOP/RES key.
Terminal reset: Set the DI terminal to 9.
Communication reset: Send a reset command through Modbus communication.

3.3 Fault Protection Action Settings

Fault Action Selection 1 (F9-47):

Units digit: Motor overload action.
Tens digit: Input phase loss action.

Fault Action Selection 2 (F9-48):

Units digit: Encoder fault action.
Tens digit: Parameter read/write abnormal action.

Fault Action Selection 3 (F9-49):

Units digit: Custom fault 1 action.
Tens digit: Custom fault 2 action.

IV. Advanced Functions and Application Examples

4.1 Multi-Motor Control Function

Motor Parameter Group Selection:

Select the current motor parameter group using F0-24.

Motor Parameter Settings:

First group: F1 group (motor parameters), F2 group (vector parameters).
Second group: A2 group (motor parameters), A5 group (vector parameters).

Switching Notes:

Switching must be performed in the stop state.
After switching, check the motor rotation direction.

4.2 PID Control Function Application

Basic Parameter Settings:

FA-00: PID setpoint source selection.
FA-02: PID feedback source selection.

PID Parameter Settings:

FA-05: Proportional gain Kp1.
FA-06: Integral time Ti1.
FA-07: Differential time Td1.

4.3 Communication Function Configuration

Basic Parameter Settings:

Fd-00: Baud rate setting.
Fd-01: Data format.
Fd-02: Local address.

Communication Control:

Run command: Communication address 0x1001.
Frequency setpoint: Communication address 0x1000.

V. Maintenance and Upkeep

5.1 Daily Maintenance Points

Regular Inspection Items:

Check the operation of the cooling fan.
Remove dust from the radiator.
Check the wiring terminals.
Check the electrolytic capacitors.

Maintenance Cycle Recommendations:

Daily: Check the operating status.
Monthly: Clean the radiator.
Annually: Conduct a comprehensive inspection.

5.2 Long-Term Storage Notes

Storage Environment Requirements:

Temperature: -20°C to +60°C.
Humidity: ≤95%RH (no condensation).

Inspection Before Reuse:

Measure the insulation resistance of the main circuit.
Check the control board.

5.3 Lifespan Prediction and Replacement

Lifespan Reference for Wear Parts:

Electrolytic capacitors: Approximately 8-10 years.
Cooling fans: Approximately 30,000-50,000 hours.

Replacement Notes:

Cut off the power supply and wait for 10 minutes before operation.
After replacement, check the parameter settings.

Conclusion

The XC-5000 series frequency converters are powerful and have superior performance. Through this guide, users can comprehensively master core skills such as operation panel usage, parameter settings, external control, and fault diagnosis. Correct installation, parameter settings, and maintenance are key to ensuring the long-term stable operation of the frequency converters. It is recommended that users refer to this guide and make appropriate adjustments according to specific working conditions to fully leverage the performance advantages of the XC-5000 frequency converters.

Table of Contents

1. Introduction

2. Basic Concept of AL-09 Overload Fault

2.1 What is AL-09 Overload Fault?

2.2 Common Manifestations of AL-09 Fault

3. Structure and Working Principle of LS Servo Drive APD-VP Series

3.1 Hardware Structure of APD-VP Series Servo Drive

3.2 Control Logic and Feedback Mechanism of Servo Drive

3.3 Working Principle of Overload Protection Mechanism

4. Causes of AL-09 Fault

4.1 Mechanical Load Abnormalities

4.2 Electrical Parameter Setting Errors

4.3 Motor or Encoder Failures

4.4 Power Supply Issues

4.5 Environmental Factors

5. Diagnostic Steps for AL-09 Fault

5.1 Preliminary Inspection

5.2 Mechanical System Inspection

5.3 Electrical Parameter Inspection

5.4 Motor and Encoder Inspection

5.5 Power Supply and Wiring Inspection

6. Solutions for AL-09 Fault

6.1 Optimization and Adjustment of Mechanical Load

6.2 Reconfiguration of Electrical Parameters

6.3 Maintenance and Replacement of Motor and Encoder

6.4 Improvement of Power Supply Stability

6.5 Control of Environmental Factors

7. Preventive Measures for AL-09 Fault

7.1 Regular Maintenance and Upkeep

7.2 Parameter Backup and Optimization

7.3 Runtime Monitoring and Alarm System

8. Case Studies

8.1 Case Study 1: AL-09 Fault Caused by Mechanical Jamming

8.2 Case Study 2: AL-09 Fault Caused by Parameter Setting Errors

8.3 Case Study 3: AL-09 Fault Caused by Unstable Power Supply

9. Conclusion and Recommendations

Introduction

Overview of the SD700 Servo System

Main Component Names and Functions of the System

Role of the Encoder in the Servo System

Working Principle of the Encoder

Description of the ER.C90 Fault

Analysis of Fault Causes

Diagnostic Steps

Solutions

Preventive Measures

Case Studies

Advanced Debugging Techniques

Conclusion

1. Introduction: The Role of the PG Card in Inverter Control Systems

2. Technical Background — Function and Principle of PG Feedback

2.1 Basic Function of the PG Card

2.2 Common PG Cards Used with the Varispeed F7

3. Identifying the SI-P1 Ver 3.04 and Its Compatibility

4. Detailed Wiring between the SI-P1 and the Encoder

4.1 Terminal Definitions

4.2 Typical Wiring Diagram

4.3 Electrical Precautions

5. Parameter Configuration and Commissioning

Commissioning Steps

6. Practical Field Experience and Case Studies

Case 1: Speed Feedback Optimization

Case 2: Direction Error due to Reversed Phases

Case 3: Noise Interference and Shielding

7. Signal Verification and Maintenance

7.1 Oscilloscope Test

7.2 Feedback Speed Monitoring

7.3 Cleaning and Care

8. Signal Mapping Comparison: SI-P1 vs PG-A2

9. Engineering Discussion and Technical Insights

10. Conclusion

11. Summary of Best Practices

Author’s Note

Basic Principles

L7 Series Characteristics

Key Components and Initialization

Display Panel Basics

Control Modes and Parameter Settings

Safety Guidelines

Product Features and Updates