Category: Other Drives

Introduction

In the field of industrial automation, Variable Frequency Drives (VFDs) are essential for controlling motor speed and torque. The Shihlin SS2 series inverter is widely recognized for its efficiency and reliability across various industrial applications. However, like any electronic device, it may encounter faults, one of which is the “ou0” fault—a common issue that can lead to downtime and affect productivity. This article provides an in-depth analysis of the “ou0” fault, its causes, and detailed solutions to help users restore normal operation swiftly.

What Is the “ou0” Fault?

The “ou0” fault code typically indicates that the inverter has detected an excessively high DC bus voltage, a condition known as overvoltage. The DC bus is a critical component in the inverter that converts AC input into DC before inversion. When the DC bus voltage exceeds the safety threshold, the inverter triggers a protective mechanism, displaying “ou0” and halting operation to prevent damage to internal components like the IGBT module. On the Shihlin SS2 inverter’s control panel, “ou0” is usually shown in red, accompanied by an abnormal status of the operation indicator light.

Common Causes of the “ou0” Fault

Overvoltage faults can stem from multiple factors, with the following being the most prevalent:

1. High Input Voltage
   If the AC input voltage exceeds the inverter’s rated range (typically 380V ±15%), the DC bus voltage rises accordingly. Grid fluctuations, poor power quality, or external disturbances like lightning strikes can contribute to this issue.
2. Regenerative Energy Feedback
   During motor deceleration, especially with high-inertia loads (e.g., CNC machines or heavy machinery), the motor can act as a generator, feeding energy back to the inverter. If the deceleration time is too short or there is no mechanism to dissipate this energy, the DC bus voltage spikes.
3. Component Aging or Failure
   DC bus capacitors play a vital role in absorbing and stabilizing voltage. Aging or damaged capacitors may fail to perform, leading to voltage fluctuations. Additionally, faults in the rectifier or inverter modules can also cause overvoltage.
4. Improper Parameter Settings
   A deceleration time set too short is a frequent misconfiguration, causing regenerative energy to accumulate rapidly. Other parameters, such as voltage regulation settings, may also impact voltage stability.
5. External Factors
   • Excessively long cables or degraded insulation can introduce voltage interference or leakage.
   • Environmental conditions like high temperatures or dust accumulation may affect the inverter’s cooling and performance.

Diagnosing the “ou0” Fault

To accurately identify the cause of the “ou0” fault, a systematic diagnostic approach is recommended:

1. Check Input Voltage
   Use a multimeter to measure the three-phase input voltage of the inverter, ensuring it falls within the Shihlin SS2 series’ rated range (typically 380V ±15%). If the voltage is too high or fluctuates significantly, investigate grid stability or external interference.
2. Review Deceleration Time Settings
   Access the inverter’s parameter settings through the control panel and check the deceleration time parameter (possibly P.02, as per the manual). If the deceleration time is too short (e.g., 2 seconds), consider extending it to 5 seconds or more to reduce regenerative energy buildup.
3. Inspect DC Bus Capacitors
   If possible, use a capacitance tester to measure the DC bus capacitors’ capacitance and equivalent series resistance (ESR). Aging capacitors may show reduced capacitance or physical damage (e.g., bulging or leakage). Replace them if necessary.
4. Evaluate Load Characteristics
   Determine if the load is high-inertia (e.g., heavy machinery or fans). High-inertia loads generate significant regenerative energy during deceleration, potentially requiring additional braking equipment.
5. Inspect Cables and Grounding
   Ensure the output cable length does not exceed the recommended limit (typically 50 meters) and check the cable insulation for integrity. Verify that the inverter is properly grounded to avoid electrical noise or static interference.
6. Use Diagnostic Tools
   If the inverter supports communication features, connect diagnostic software to view detailed fault logs. Record the operating condition during the fault (e.g., acceleration, deceleration, or constant speed) for further analysis.

Solutions

Based on the diagnosis, the following measures can resolve the “ou0” fault:

1. Adjust Deceleration Time
   Extending the deceleration time is a simple and effective way to address regenerative energy issues. Access the parameter settings via the control panel and adjust the deceleration time (e.g., P.02) from a short duration (like 2 seconds) to 5 seconds or longer, depending on the load characteristics.
2. Install a Braking System
   For high-inertia loads, installing a braking resistor and braking unit is highly recommended. The braking resistor dissipates excess regenerative energy as heat, preventing the DC bus voltage from rising beyond the protection threshold. Ensure the resistor matches the inverter model, as specified in the Shihlin SS2 manual.
3. Stabilize Input Voltage
   If the grid voltage is unstable, consider installing a voltage regulator or reactive power compensation device. A line reactor can also help filter high-order harmonics, improving power quality.
4. Replace Faulty Components
   If the capacitors or other internal components are damaged, they should be replaced by a qualified technician. Ensure the power is disconnected and safety protocols are followed during replacement.
5. Optimize Environmental Conditions
   Ensure the inverter is installed in a well-ventilated, temperature-controlled environment. Regularly clean the heat sink and fan to prevent dust buildup that could impair cooling.
6. Reset Parameters
   If parameter settings may be incorrect, reset the inverter to factory defaults (often by holding the “STOP/RESET” key while powering on, as per the manual). Reconfigure the necessary parameters afterward.

Preventive Measures

To prevent the recurrence of the “ou0” fault, consider the following:

• Regular Maintenance: Inspect the inverter’s capacitors, connectors, and cooling system every 6-12 months to ensure optimal condition.
• Monitor Power Quality: Use a power quality analyzer to periodically check the input voltage stability and address potential issues early.
• Optimize Parameter Settings: Adjust acceleration and deceleration times to match the load characteristics, ensuring compatibility with the application.
• Install Protective Equipment: In lightning-prone areas, install surge protection devices to safeguard the inverter from transient overvoltage.

Case Study

In a manufacturing plant, a Shihlin SS2 inverter controlling a CNC machine frequently reported the “ou0” fault during rapid deceleration. Technicians first measured the input voltage, confirming it was within 380V ±10%, ruling out power supply issues. They then reviewed the parameters and found the deceleration time set to 2 seconds, which was too short. After extending it to 5 seconds, the fault ceased. To further enhance reliability, the plant installed a braking resistor, effectively managing the regenerative energy from the high-inertia load. This case highlights the importance of proper parameter adjustments and hardware upgrades in resolving the “ou0” fault.

Conclusion

The “ou0” fault in the Shihlin SS2 inverter is typically an overvoltage issue caused by factors like input voltage anomalies, regenerative energy buildup, or component failure. Through systematic diagnosis (e.g., checking voltage, adjusting parameters, installing braking systems), users can effectively address the issue. Regular maintenance and optimized settings are key to preventing future faults. If the problem persists, professional technical support is advised to ensure safe and reliable operation.

Common Overvoltage Fault Codes and Solutions

Below is a summary of typical overvoltage faults in inverters for reference:

Fault Code	Description	Possible Causes	Solutions
OV1	Overvoltage during acceleration	High input voltage, short acceleration time	Extend acceleration time, check input voltage
OV2	Overvoltage at constant speed	Regenerative energy buildup, capacitor failure	Check capacitors, install braking unit
OV3	Overvoltage during deceleration	Short deceleration time, high-inertia load	Extend deceleration time, install braking resistor
OU	General overvoltage alarm	High DC bus voltage, external interference	Check voltage, address cable issues, install lightning protection

Note: The Shihlin SS2 may use “ou0” to denote overvoltage, which should be confirmed with the specific manual.

In the field of industrial automation control, inverters, as the core equipment for motor speed regulation, are widely used in various scenarios requiring graded speed regulation, such as fans, pumps, and conveyor belts. This article will take the ZK880-N positive control inverter as an example, combined with official technical documentation and practical application scenarios, to elaborate in detail on how to achieve three-stage speed control through DI digital input terminals, providing systematic guidance from hardware wiring to parameter settings.

I. Technical Principles of Three-Stage Speed Control

The essence of three-stage speed control is to preset the motor operating frequency into three different levels through the multi-stage speed instruction function of the inverter. Users can select the corresponding frequency band through external switch signals to realize the graded regulation of motor speed. The ZK880-N inverter uses digital input terminals (DI) as the trigger signal source, combined with function code parameter settings, to build a flexible and reliable multi-stage speed control system.

II. Hardware Wiring Implementation Steps

1. Terminal Function Definition

According to control requirements, the DI1-DI3 digital input terminals need to be configured as multi-stage speed control ports. Refer to the inverter terminal distribution diagram, with standard wiring terminals located in the control circuit interface area.

2. Wiring Specifications

• Power Connection: Ensure that the main circuit power supply (R/S/T) and control circuit power supply (usually +24V) of the inverter are correctly connected.
• DI Terminal Wiring:
  • DI1: As the first-stage speed trigger terminal, it is recommended to connect a normally open contact switch.
  • DI2: As the second-stage speed trigger terminal.
  • DI3: As the third-stage speed trigger terminal.
  • Common Terminal (COM): The signal common terminal for all DI terminals, which should be connected to the other end of the switch.

3. Wiring Precautions

• The switch signal voltage range must comply with the DI terminal input specifications (5-30V DC).
• It is recommended to use shielded twisted pair cables for signal transmission to avoid electromagnetic interference.
• After wiring, use a multimeter to detect the insulation resistance between terminals to ensure there is no short circuit.

III. Detailed Explanation of Core Parameter Settings

The following function codes need to be configured through the operation panel or dedicated software:

1. DI Terminal Function Mapping

Function Code	Parameter Item	Setting Value	Function Description
F4-00	DI1 Function Selection	4	Multi-stage Speed 1 (corresponding to the first-stage speed)
F4-01	DI2 Function Selection	5	Multi-stage Speed 2 (corresponding to the second-stage speed)
F4-02	DI3 Function Selection	6	Multi-stage Speed 3 (corresponding to the third-stage speed)

2. Multi-Stage Speed Frequency Settings

Function Code	Parameter Item	Setting Value	Typical Application Scenarios
FC-00	Multi-stage Speed 1 Frequency	20Hz	Light load start/low-speed operation
FC-01	Multi-stage Speed 2 Frequency	35Hz	Normal working speed
FC-02	Multi-stage Speed 3 Frequency	50Hz	High-speed discharge/emergency acceleration

3. Operating Parameter Configuration

Function Code	Parameter Item	Recommended Value	Function Description
F6-00	Acceleration Time 1	8.0s	Transition time from first-stage to second-stage speed
F6-01	Deceleration Time 1	5.0s	Transition time from second-stage to first-stage speed
F6-02	Acceleration Time 2	12.0s	Transition time from second-stage to third-stage speed
F6-03	Deceleration Time 2	8.0s	Transition time from third-stage to second-stage speed
FC-16	Operation Instruction Selection	1	Terminal control mode
FC-17	Fault Reset Selection	1	Allow DI terminals to perform fault reset

IV. Realization of Three-Stage Speed Control Logic

1. Single Terminal Single-Stage Speed Mode

• Only DI1 is closed: The motor operates at the frequency set by FC-00 (20Hz).
• Only DI2 is closed: The motor operates at the frequency set by FC-01 (35Hz).
• Only DI3 is closed: The motor operates at the frequency set by FC-02 (50Hz).

2. Combined Control Mode (Advanced Application)

Through function codes FC-03 to FC-07, combined stage speeds can be set:

• DI1+DI2 closed: Execute the frequency set by FC-03 (reserved for extended stage speed).
• DI2+DI3 closed: Execute the frequency set by FC-04 (reserved for extended stage speed).
• Special application scenarios: Realize automatic stage speed switching logic through PLC programming.

V. Commissioning and Verification Process

1. No-Load Test Stage

1. Disconnect the motor load and only retain the inverter and dummy load.
2. Close the DI1-DI3 switches in turn to observe whether the output frequency is consistent with the set value.
3. Use an oscilloscope to detect the output voltage waveform and confirm there is no distortion.

2. Load Commissioning Stage

1. Gradually load to the rated load.
2. Test the current impact during stage speed switching (should be less than 1.5 times the rated current).
3. Verify whether the acceleration/deceleration time meets the process requirements.

3. Abnormal Handling Test

1. Simulate DI terminal signal adhesion fault.
2. Verify the effectiveness of the FC-17 fault reset function.
3. Test the reliability of overload protection (OL) action.

VI. Typical Application Cases

In a certain water plant’s constant pressure water supply system, the three-stage speed control of the ZK880-N inverter is adopted:

• First-stage speed (25Hz): Maintain the basic pressure of the pipe network during night low-peak periods.
• Second-stage speed (40Hz): Meet normal water demand during daytime water supply.
• Third-stage speed (50Hz): Quickly supplement the pipe network pressure during peak water consumption periods.

Through the automatic switching of stage speeds by pressure sensor signals, an energy-saving rate of 32% is achieved, and the pressure fluctuation range is controlled within ±0.02MPa.

VII. Maintenance and Optimization Suggestions

1. Regularly check the reliability of DI terminal wiring, and recommend tightening every six months.
2. Recheck the FC-00 to FC-02 parameter settings every quarter according to load characteristics.
3. Upgrade to the latest firmware version (currently V2.13) to obtain an optimized stage speed switching algorithm.
4. For impact loads, it is recommended to add an input reactor to improve power quality.

By following the above systematic implementation steps, users can efficiently achieve the three-stage speed control function of the ZK880-N inverter. In practical applications, it is necessary to combine specific process requirements and optimize parameters to achieve the best control effect. With the development of Industry 4.0, this inverter supports the Modbus-RTU communication protocol and can be integrated with the host computer system to achieve more intelligent stage speed scheduling management.

Introduction

Inverters are vital components in industrial automation, enabling precise control over motor speed and torque across various sectors, including manufacturing and energy. The Shihlin SS2 series inverter, manufactured by Shihlin Electric, is widely recognized for its reliability and performance. However, like any complex equipment, it may encounter faults during operation. One such issue is the E0 fault, which can be perplexing for users due to its specific triggering conditions. This article provides a comprehensive analysis of the E0 fault in the Shihlin SS2 inverter, detailing its meaning, causes, solutions, and preventive measures to assist users in restoring normal operation efficiently.

1. Meaning of the E0 Fault

According to the Shihlin SS2 Series Inverter Manual (version V1.07), the E0 fault is triggered under specific conditions related to the inverter’s parameter settings and operation mode. Specifically, when parameter P.75 (stop function setting) is set to 1, and the inverter is operating in a mode other than PU (panel operation mode) or H2 (high-frequency mode), pressing the stop button (labeled as “(20) key” in the manual) for 1.0 second causes the inverter to stop. The display shows “E0,” and all functions are disabled or reset. This behavior acts as a protective mechanism to prevent unintended operation or potential damage under these conditions.

Interestingly, the manual also lists E0 in the fault code table under “00(H00)” as “no fault” (无异常), which may indicate a different context, such as a default or reset state in fault logging. This dual reference suggests that E0’s meaning depends on the operational context, but the primary focus here is its association with the stop function and parameter P.75.

2. Causes of the E0 Fault

To effectively resolve the E0 fault, understanding its causes is essential. Based on the manual and related information, the following are the primary reasons for the E0 fault:

• Parameter P.75 Configuration: Parameter P.75 governs the inverter’s stop behavior. When set to 1, it enables a deceleration stop function. In non-PU or non-H2 modes, pressing the stop button for 1 second triggers the E0 fault, as the inverter interprets this as an invalid operation under the current settings.
• Operation Mode Restrictions: The E0 fault is specific to non-PU and non-H2 modes. PU mode allows direct control via the inverter’s control panel, while H2 mode may relate to specific high-frequency applications. Operating in external control mode (e.g., via external signals) with P.75 set to 1 increases the likelihood of triggering E0.
• External STE/STR Command Interference: External start/stop commands (STE/STR) can conflict with the inverter’s settings. The manual notes that when E0 occurs, these external commands are canceled, suggesting that signal interference may contribute to the fault.
• Operator Error: Inadvertently pressing the stop button for more than 1 second in an incompatible mode can trigger the E0 fault. This is particularly common during initial setup, debugging, or when operators are unfamiliar with the inverter’s operation.

It’s worth noting that earlier versions of the Shihlin SS2 manual (e.g., V1.01) describe E0 as a communication error related to parity check issues. This discrepancy indicates that fault code definitions may have evolved across manual versions, with V1.07 providing the most relevant information for modern SS2 inverters.

3. Solutions for the E0 Fault

Resolving the E0 fault involves a systematic approach to eliminate its triggers and restore normal operation. The following steps, derived from the manual (version V1.07), are recommended:

1. Cancel External STE/STR Commands:
   • Inspect the inverter for any external start/stop (STE/STR) signals that may be interfering with its operation.
   • Cancel these inputs to ensure no external commands conflict with the inverter’s settings. In program operation mode, manual signals typically do not require clearing, but verifying the absence of interference is critical.
2. Reset the Inverter:
   • Locate the stop button (labeled “(20) key”) on the control panel.
   • Press and hold it for at least 1.0 second to clear the E0 fault and reset the inverter to an operational state. This is a direct method recommended in the manual.
3. Check and Adjust Parameter P.75:
   • Access the inverter’s parameter setting menu to review the value of P.75.
   • If P.75 is set to 1 and this is not suitable for your application, change it to 0 (the factory default) or another appropriate value. Refer to section 5.33 of the manual for detailed guidance on adjusting P.75.
4. Verify Operation Mode:
   • Ensure the inverter is operating in the correct mode (PU or H2, if required for your application).
   • Switch to the appropriate mode to prevent the fault from recurring.
5. Perform a Parameter Reset:
   • If the above steps do not resolve the issue, use parameters P.996 or P.997 to reset the inverter. These parameters can clear fault records or restore factory settings, as outlined in sections 5.78 and 5.80 of the manual.
6. Seek Professional Assistance:
   • Persistent faults may indicate hardware issues (e.g., faulty motherboard or wiring errors) or complex configuration problems.
   • Contact Shihlin Electric’s technical support team via their official website or arrange for the inverter to be inspected by the manufacturer.

The following table summarizes the causes and solutions for the E0 fault:

Possible Cause	Solution
P.75 set to 1, non-PU/H2 mode operation	Adjust P.75 to 0 or other values (manual section 5.33)
Stop button pressed for 1.0 second	Press stop button for 1.0 second to reset
External STE/STR command interference	Cancel external commands, check wiring
Hardware or configuration issues	Reset using P.996/P.997 or contact manufacturer

4. Preventive Measures for E0 Fault

To minimize the occurrence of E0 faults and ensure reliable inverter operation, consider the following preventive measures:

• Proper Parameter Configuration:
  • During installation and commissioning, thoroughly review the Shihlin SS2 Series Inverter Manual (version V1.07) to ensure parameters like P.75 are correctly set for your application.
  • Avoid modifying parameters without understanding their functions to prevent unintended faults.
• Regular Maintenance:
  • Conduct periodic inspections of the inverter’s wiring, cooling system, and control panel to check for loose connections, dust buildup, or overheating.
  • Regular maintenance reduces the risk of faults caused by environmental or mechanical issues.
• Operator Training:
  • Train all personnel operating the SS2 inverter on its proper use and fault-handling procedures.
  • Ensure the manual is readily available for quick reference during operation or troubleshooting.
• Power Supply Stability:
  • Use voltage stabilizers or surge protectors to protect the inverter from power fluctuations, which can contribute to faults.
  • A stable power supply is essential for long-term reliability.
• Fault Monitoring and Logging:
  • Maintain a record of all fault occurrences, including their conditions and resolutions.
  • Regularly monitor the inverter’s performance to identify and address potential issues early.

5. Conclusion

The E0 fault in the Shihlin SS2 inverter, while initially confusing, can be effectively managed by understanding its association with parameter P.75 and specific operation modes. By following the outlined steps—canceling external STE/STR commands, resetting the inverter, adjusting P.75, and verifying the operation mode—users can typically resolve the fault quickly. Additionally, adopting preventive measures such as proper parameter setup, regular maintenance, operator training, power protection, and fault monitoring can significantly reduce the likelihood of E0 faults. For persistent issues, contacting Shihlin Electric’s technical support or arranging professional inspection is advisable. By implementing these strategies, users can ensure the stable and efficient operation of their SS2 inverters, maximizing performance in industrial applications.

Key Citations

1. System Overview

Constant pressure water supply technology is widely used in modern industrial and civil water systems for efficient and energy-saving operation. This project uses the Milan M5000 inverter as the control core, combined with the YTZ-150 potentiometric remote pressure gauge, to construct a closed-loop constant pressure control system. It enables automatic adjustment of a single water pump to ensure the outlet pressure remains stable within the set range.

The system features low cost, easy maintenance, and fast response, making it suitable for small water supply systems, factory cooling water circulation, boiler water replenishment, and more.

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2. Main Hardware and Functional Modules

1. Inverter: Milan M5000 Series

• Built-in PID controller
• Supports multiple analog inputs (0-10V, 0-5V, 4-20mA)
• Provides +10V power output terminal for sensor power supply

2. Pressure Sensor: YTZ-150 Potentiometric Remote Pressure Gauge

• Resistive output with a range of approx. 3–400Ω
• Rated working voltage ≤6V, but 10VDC tested in practice with stable long-term operation
• Outputs a voltage signal (typically 0–5V) varying with pressure via a voltage divider principle

3. Control Objective

• Adjust pump speed using the inverter to maintain constant pipe pressure
• Increase frequency when pressure drops, and decrease when pressure exceeds the setpoint to save energy

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3. Wiring and Jumper Settings

1. 3-Wire Sensor Wiring (Tested with 10V)

Sensor Wire	Function	Inverter Terminal
Red	+10V supply	Connect to +10V
Green	Ground (GND)	Connect to GND
Yellow	Signal output	Connect to VC1 input

2. Analog Input Jumper JP8

• Default: 1–2 connected, indicating 0–10V input
• Keep the default setting in this project (no need to switch to 2–3)

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4. PID Parameter Settings (Based on Field Use)

Parameter	Description	Value	Note
P7.00	Enable closed-loop control	1	Enable PID control
P7.01	Setpoint source	0	Digital input from panel
P7.02	Feedback source	0	VC1 analog input (0–10V)
P7.05	Target pressure value (%)	30.0	Corresponds to 0.3MPa if P7.24=1.000
P7.07	Feedback gain	1.00	Linear scaling factor for feedback
P7.10	PID control structure	1	Proportional + integral control
P7.11	Proportional gain	0.50	Recommended initial value
P7.12	Integral time constant	10.0	In seconds
P7.24	Pressure sensor range (MPa)	1.000	1.000 MPa full-scale
P1.19	Maximum voltage input	5.00	Matched to 0–5V signal range

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5. Sleep Function Configuration

To enable energy saving when there is no pressure demand, the inverter can be configured to sleep:

Parameter	Description	Value	Note
P7.19	Wake-up threshold	0.001	Minimum pressure to resume operation (MPa)
P7.20	Sleep threshold	1.000	Enter sleep mode above this value (MPa)
P7.23	Constant pressure mode	1	One-pump control mode

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6. PID Tuning Guidelines

1. After starting the system, observe pressure fluctuations:
   • If large oscillations, reduce P7.11 (proportional gain)
   • If sluggish response, reduce P7.12 (integral time)
2. Aim to maintain output pressure within ±2% of the P7.05 set value
3. Ensure return pipes have damping to prevent sudden pressure spikes

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7. Key Considerations

1. Keep JP8 jumper at default 1–2 for 0–10V input
2. YTZ-150 sensor has been tested with 10V power supply and works stably
3. Ensure proper grounding (PE terminal) to avoid PID interference from common-mode noise
4. If feedback signal is noisy, add a filter capacitor (0.1–0.47μF) between VC1 and GND

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8. Conclusion

With this design, the Milan M5000 inverter combined with the YTZ-150 pressure sensor delivers a cost-effective and reliable constant pressure control solution for water systems. The inverter’s built-in PID control simplifies implementation compared to external PLCs and offers strong performance with minimal tuning. As long as power supply, signal matching, and grounding are properly managed, the system achieves excellent closed-loop control stability.

Introduction

The Delixi EM60 series inverter is a robust variable frequency drive (VFD) designed to regulate the speed and torque of AC motors in industrial applications. Engineered for reliability, it features advanced protective mechanisms to safeguard both the inverter and the connected motor. One such protection is the “quick current limit,” which prevents damage from sudden overcurrent conditions. However, when this limit is exceeded for too long, the inverter triggers the ERR34 fault code, known as “quick current limit timeout” (快速限流超时). This article explores the meaning of the ERR34 fault, its potential causes, and provides a detailed guide on how to troubleshoot and repair this issue, drawing on the Delixi EM60 series user manual and practical VFD maintenance principles.

What Does ERR34 Mean?

The ERR34 fault code indicates that the inverter’s output current has surpassed the quick current limit threshold for a duration exceeding the specified timeout period. In the Delixi EM60 series, this protective feature is part of the motor control strategy, managed through parameters in the P1 group (pages 31-73 of the user manual). The quick current limit activates during transient overcurrent events—such as sudden load spikes or short circuits—by reducing the output frequency or voltage to stabilize the current. If the current remains high beyond the timeout threshold (typically a few seconds), the inverter halts operation and displays ERR34 to prevent damage.

This fault serves as a critical alert, signaling that the system could not resolve an overcurrent condition within the allotted time. Understanding its implications is key to diagnosing whether the issue lies in the motor, wiring, parameters, or the inverter itself.

Potential Causes of ERR34

Several factors can trigger the ERR34 fault. Based on the manual’s fault diagnosis section (pages 191-199) and general VFD operation, the following are the most likely culprits:

1. Motor Overload
   Excessive mechanical load, such as a jammed rotor or heavy machinery, forces the motor to draw more current than the inverter can safely handle, activating the current limit.
2. Incorrect Parameter Settings
   Misconfigured settings in the P1 group (motor control parameters, pages 31-73) or P3 group (programmable functions, pages 47-117), such as a low current limit or short timeout period, can cause the fault to trigger prematurely.
3. Power Supply Instability
   Voltage fluctuations, harmonics, or transients in the input power can disrupt the inverter’s ability to regulate current, as emphasized in the safety guidelines (pages 6-7).
4. Wiring Issues
   Loose connections, damaged cables, or short circuits between the inverter and motor can lead to abnormal current spikes. The manual’s installation section (page 213) highlights the importance of secure wiring.
5. Motor or Inverter Faults
   Internal motor issues (e.g., shorted windings) or inverter hardware failures (e.g., damaged IGBT modules or current sensors) can sustain overcurrent conditions.
6. Environmental Factors
   Dust accumulation or poor ventilation, as observed in the image of an EM60G0R7S2 inverter, can overheat the unit, exacerbating current-related problems.

Troubleshooting the ERR34 Fault

Diagnosing the ERR34 fault requires a systematic approach. The following steps, inspired by the manual’s troubleshooting sections (pages 56-128) and practical experience, will help identify the root cause:

1. Ensure Safety
   Disconnect the power supply and verify with a multimeter that the system is de-energized, adhering to the caution label warning against live servicing.
2. Check Motor Load
   Inspect the motor and driven equipment for mechanical issues like binding or overloading. Measure the current draw with a clamp meter and compare it to the motor’s rated capacity.
3. Review Parameter Settings
   Use the inverter’s keypad (featuring “MODE,” “ENTER,” and arrow buttons) to access the P1 group. Verify the current limit (e.g., P1-03) and acceleration/deceleration times (P1-09, P1-10, page 159). Adjust if they are too restrictive for the application.
4. Inspect Wiring
   Examine all connections between the inverter and motor for looseness, fraying, or burn marks. Test for continuity and insulation resistance to rule out shorts.
5. Assess Power Supply
   Measure the input voltage to ensure it’s within the specified range (e.g., 380V ± 15% for three-phase models). Use a power quality analyzer to detect noise or surges.
6. Monitor Environmental Conditions
   Check the inverter’s surroundings for dust or high temperatures (recommended range: 0-40°C). Clean the unit and ensure proper ventilation.
7. Reset and Test
   After addressing potential issues, reset the fault via the “STOP” button or power cycle (page 128). Run the system at a low speed to observe if ERR34 reoccurs.

Solutions and Repairs

Once the cause is pinpointed, apply these solutions:

1. Reduce Overload
   Lighten the mechanical load or upgrade to a higher-capacity motor and inverter if the demand exceeds specifications.
2. Adjust Parameters
   Increase the current limit or extend the timeout period in the P1 group to accommodate normal operation. For example, lengthening acceleration time (P1-09) can reduce startup current spikes.
3. Stabilize Power
   Install a voltage stabilizer or harmonic filter to ensure consistent input power.
4. Repair Wiring
   Tighten connections or replace faulty cables, ensuring compliance with the manual’s wiring guidelines (page 213).
5. Fix Hardware
   • Motor: Test windings with an insulation tester; repair or replace if defective.
   • Inverter: If internal components are suspected (e.g., IGBTs), consult Delixi support for repair, as detailed diagnostics may require proprietary tools (P8 group, page 66).
6. Improve Environment
   Relocate the inverter to a cleaner, cooler area or add cooling fans to mitigate thermal stress.

Preventive Measures

To avoid future ERR34 faults:

• Conduct regular maintenance on the motor and machinery to prevent overloads.
• Periodically review P1 and P3 group settings, adjusting for changes in load or application (pages 31-117).
• Install surge protectors to safeguard against power issues.
• Clean the inverter routinely to remove dust, as recommended in the safety sections (pages 6-7).
• Train staff on parameter configuration and fault handling, leveraging the manual’s application cases (pages 180-183).

Conclusion

The ERR34 fault code in the Delixi EM60 series inverter is a vital safeguard against prolonged overcurrent conditions. Whether caused by overload, parameter errors, wiring faults, or environmental factors, this issue can be resolved through careful troubleshooting and targeted repairs. By following the steps outlined and adhering to the user manual’s guidance, users can restore functionality and enhance system reliability. For complex hardware failures, professional assistance from Delixi or a certified technician ensures long-term performance and safety.

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In field maintenance work, we often encounter situations where equipment displays fault codes that are not documented in the user manual. This is especially common with domestic brands or cloned inverters. This article details the entire process of diagnosing and repairing a ZHZK ZK880-N series inverter that first displayed an ERR23 fault (ground short circuit), and after repairs, encountered an ERR42 fault (speed deviation too large). Through fault code analysis and comparative research, we uncover the significant similarities between this inverter and the Inovance MD380 series and explore the logic issues that arise.

1. Equipment Background

The inverter was applied in an industrial fan system at a factory, used for speed control and energy saving. After years of operation, the equipment suddenly failed and displayed ERR23. The user tried replacing the motor without success, and then entrusted our team with on-site diagnosis and repair.

2. First Fault: ERR23 — Ground Short Circuit

1. Fault Symptom

The inverter powered on and passed self-check, but tripped with an ERR23 alarm immediately upon startup. The motor did not rotate, and no output current was detected.

2. Fault Analysis

Based on experience, ERR23 typically indicates a ground short caused by:

• Motor winding insulation breakdown
• Damaged or damp output cables
• Internal failure of power components (IGBT)

3. Troubleshooting and Repair

1. Insulation Testing: Used a megohmmeter to check insulation between U/V/W and ground — >200MΩ, confirmed normal; cables also intact.
2. Output Voltage Check: Powered on without load and checked inverter output with an oscilloscope — no PWM waveform, indicating power circuit issues.
3. Drive Board Check: Found burn marks on the drive board; further inspection confirmed IGBT failure.
4. Component Replacement: Replaced IGBT module and repaired burned-out optocouplers and resistors in the drive circuit.
5. Testing: Simulated load in factory conditions — inverter output normal, PWM stable, fan rotates properly.

ERR23 fault was successfully resolved.

3. Post-Repair Fault: ERR42 — Speed Deviation Too Large

1. On-Site Issue

After reinstalling at the user site, the inverter powered on and passed self-check. Upon startup, it ran for about 1–2 seconds and then tripped with ERR42.

2. Confusion and Clue

The ZHZK manual did not mention ERR42, leaving no immediate path forward. We pursued two directions:

• First, determine if it was a false alarm — due to interference or wiring.
• Second, check for hidden parameters or compatibility issues — given the extremely brief manual.

3. Comparative Breakthrough — Inovance MD380

An engineer noticed that the ZHZK ZK880-N closely resembled the Inovance MD380 series in appearance, menus, and parameter structures. We referenced the MD380 manual and found:

ERR42: Speed deviation too large.
Applies when using encoder feedback in vector control (F0-01=1), and actual speed deviates significantly from target.

But the parameter F0-01 was set to 0, i.e., sensorless vector control (SVC), where no encoder feedback is involved. Logically, such an error shouldn’t occur in this mode.

4. Validation Through Trial and Error

We tested by changing F0-01 from 0 to 2 — i.e., switching to V/F control mode.

• Upon restart, the inverter operated normally.
• ERR42 no longer occurred.

This confirmed that:

• Although ERR42 should only trigger in closed-loop vector control, ZHZK’s firmware retained some residual logic from MD380, allowing the error even in SVC mode.

5. ZHZK ZK880-N vs. Inovance MD380 — An In-Depth Comparison

Several clues support that ZHZK is a cloned or customized variant of Inovance:

1. Parameter numbering identical: Including F0-01, F9 group, etc.
2. Fault codes mostly match: Even undocumented ZHZK codes behave like MD380 ones.
3. Hardware layout extremely similar: IGBT drive and control board layout nearly identical.
4. UI and navigation same: Menu structure, key functions, and parameter copy behavior identical.

Conclusion: ZHZK ZK880-N is highly likely based on early Inovance versions — a rebranded or cut-down variant, with leftover logic causing such confusion.

6. Key Repair Takeaways

1. Don’t rely solely on manuals when fault codes are missing: Look at similar products.
2. SVC mode in clone inverters is often unstable: Recommend V/F for reliability.
3. Always document parameters and take screenshots: Helps future diagnostics.
4. Validate by logic and testing: ERR42 was resolved by matching control logic with firmware behavior.

7. Conclusion

This case shows that engineers must go beyond the manual when diagnosing inverter faults — especially for custom or generic brands. The transition from ERR23 to ERR42 and its resolution illustrates the importance of comparative research, logical reasoning, and on-site validation.

For clone or OEM-modified inverters, avoid complex control modes like vector control unless absolutely necessary. Simplicity brings reliability in harsh field environments.

This process exemplifies how practical engineering insight bridges the gap between unknown errors and restored operation.

I. Phenomenon Review

After power-on, the panel alternately displays “‑L‑C‑” and the A29/Err29 code. According to the corresponding entry in the manual:

“Cumulative Power-On Time Reaches Fault Err29 — ① The cumulative power-on time has reached the preset value; ② Use the parameter initialization function to clear the recorded information” (see user screenshot).

This indicates that it is not a hardware failure but rather a software logic lock: when the internally recorded Power-On Time (cumulative power-on hours) exceeds the manufacturer’s preset threshold, the inverter actively enters a protection/shutdown state until the user performs a “parameter initialization” or other unlocking action.

II. Why the “Running Hours Lock” Exists

Driven by Business Models

Some low-cost domestic brands adopt a “runtime limit” strategy, treating inverters as “quasi-leased” equipment:

• The device is shipped with the main machine in the first year, and after 8,000 to 10,000 hours of operation, it locks, requiring the customer to pay the remaining balance or renew the subscription to obtain authorization for reset.

Post-Sales Risk Control

In the “semi-OEM” market, manufacturers find it difficult to control the final application environment. Binding the lifespan limit to the software layer can compress the warranty scope and reduce large claims due to the burnout of high-power components caused by overloading.

Spare Parts Sales and Brand Loyalty

Forces end-users to return to the original manufacturer or authorized repair points for “unlocking + maintenance,” driving sales of spare parts and upgrade packages.

III. Triggering Mechanism Principle of A29/Err29

MCU-Integrated EEPROM/Flash Timer Writing to “Cumulative Power-On Counter”

• During power-on self-check, compare the Counter with the Limit.
• If ≥ Limit → Set Fault Flag → Output relay disconnects, and the panel reports Err29.
• Even after power-off and restart, the counter value remains saved in the EEPROM, so the fault “sticks” unless Parameter Initialize is executed or new firmware is flashed.

⚠️ Unlike ordinary faults (such as phase loss or overcurrent, which are instantaneous alarms), Err29 completely prohibits inverter output before reset, so the motor will not run, and the LED only cycles through error codes.

IV. Troubleshooting and Reset Steps from an Engineer’s Perspective

Step	Operation Points	Purpose
1. Confirm the model’s firmware version	Some versions hide the runtime limit menu; read the EEPROM to check; query the version number via the panel or serial command.	Determine if direct initialization is supported.
2. Back up all parameters	Use the keyboard to copy or serial software to export the parameter table.	Prevent the loss of process recipes after initialization.
3. Execute “Parameter Initialization”	Menu path: System Settings → Parameter Management → Initialize (refer to the manual for specific key sequences). After execution, the counter is automatically erased, and factory defaults are restored.	Clear the cumulative power-on time and resolve Err29.
4. Rewrite the backed-up parameters	Check item by item according to the backup table or use a PC debugging tool to write back in batches.	Restore the original logic and process limits.
5. Test run & observe the counter	Run for a short time to confirm no recurrence of A29; if the counter value still rises rapidly, check the motherboard’s RTC/timing interrupt for abnormalities.	Rule out hardware timing circuit faults.

V. Bypassing and Deep Modifications (Advanced Topics, for Reference Only)

Under legal and compliant premises, the following practices are common in authorized service centers or when users have terminated the after-sales agreement with the manufacturer:

Modify the Counter Threshold

• Directly increase the Limit in engineering mode (e.g., to 99,999 h).
• Drawback: In some older firmware versions, the threshold is hardcoded, and the menu is hidden.

Rewriting the EEPROM

• Use ISP or offline programmer to read the EEPROM image, manually modify the counter bytes, and then write back.
• Requires disassembly and possession of electronic soldering and programming tools.

Flashing Time-Unlimited Firmware

• Official “overseas” or “engineering test” firmware often removes the runtime limit; after replacing the entire MCU Flash, the limit is completely removed.
• Risk: Flashing failure may brick the device; may involve copyright issues.

VI. Impact on Enterprise Operations and Maintenance

Impact Point	Description	Coping Strategy
Production Downtime Loss	Accidental triggering of Err29 can lead to a complete line shutdown.	Include “running hours warning” monitoring in the PM plan to arrange maintenance windows in advance.
Maintenance Costs	If unauthorized, need to pay for unlocking or replace the entire unit.	Sign a long-term maintenance package with the manufacturer or train in-house technicians to master initialization skills.
Spare Parts Warehousing	Frequent lockouts increase the demand for backup units.	Equip key processes with hot backup drives to reduce the impact of lockouts on production capacity.

VII. Legal and Ethical Discussion

Software Lock vs. Contract Law: If the sales contract does not explicitly state the “runtime limit lock,” the manufacturer’s setting of software obstacles may violate the “right to know” clause of the Consumer Rights and Interests Protection Law.

Right-to-Repair: Internationally, more and more countries emphasize users’ right to repair their purchased equipment independently, opposing excessive software restrictions. Designs like “Err29” may face compliance reviews in European and American markets.

Balanced Viewpoint: Manufacturers use software locks to prevent equipment from continuing to operate in harsh environments beyond their designed lifespan, potentially causing safety accidents; however, they should disclose this protection logic transparently in advance and provide officially authorized ways to remove it.

VIII. Conclusion and Recommendations

A29/Err29 is not an electrical fault but a “running hours lock.” It can be cleared through “parameter initialization,” but attention must be paid to backing up/restoring process parameters.

It is recommended that enterprises establish a running time ledger and conduct planned maintenance or apply for an official extension of the service package when approaching the threshold to avoid line shutdowns.

For organizations with mature electronic technology teams, evaluating the flashing of time-unlimited firmware or replacing the brand may reduce long-term maintenance costs.

From an industry standard perspective, manufacturers should clearly state this protection logic in the sales contract and manual to maintain supply chain integrity.

I. Detailed Explanation of Operation Panel Functions

1. Overview of Operation Panel Functions
The operation panel of the Koreachuan KRC9 series inverter integrates functions such as parameter setting, status monitoring, and operation control. The core key functions are as follows:

• Programming Key: Enters or exits the menu.
• Enter Key (ENTER): Confirms parameters or navigates to the next menu level.
• Increment/Decrement Keys: Adjust parameter values.
• Shift Key: Switches display interfaces or parameter positions.
• Run/Stop/Reset Key: Controls start/stop or resets the inverter.
• Multi-function Selection Key (MP3): Switches between functional modes.

2. Password Management

• Set Password: Press the MP3 key to select password setting, enter the password, and confirm with ENTER.
• Clear Password: Enter the correct password and press MP3 to exit the password setting mode.

3. Parameter Access Permissions

• Set Restrictions: Enter the parameter setting interface, select parameters, and set permissions (e.g., read-only/write-only).
• Remove Restrictions: Restore permissions to default settings.

4. Factory Parameter Management

• Restore Factory Settings: Set PP-01 to 1 to reset parameters to factory defaults.
• Backup/Restore Parameters: Set PP-01 to 4 to backup parameters, or to 501 to restore from backup.

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II. External Control Setup Guide

1. External Terminal Forward/Reverse Control

• Wiring Instructions:
  • Forward Rotation: Connect to DI1 terminal.
  • Reverse Rotation: Connect to DI2 terminal.
• Parameter Configuration:
  • P0-02: Set to 1 (terminal control).
  • P4-00: Set to 1 (forward rotation).
  • P4-01: Set to 2 (reverse rotation).

2. External Potentiometer Speed Control

• Wiring Instructions: Connect the potentiometer output to AI1 or AI2 terminal.
• Parameter Configuration:
  • P0-03: Set to 2 (AI1 setting) or 3 (AI2 setting).
  • P4-13/P4-14: Set the potentiometer input range and corresponding frequency range.

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III. Fault Codes and Troubleshooting Solutions

1. Common Fault Codes

Fault Code	Description	Possible Causes
Err02	Acceleration Overcurrent	Output circuit grounded/shorted
Err03	Deceleration Overcurrent	Output circuit grounded/shorted
Err04	Steady-state Overcurrent	Output circuit grounded/shorted
Err05	Acceleration Overvoltage	Input voltage too high
Err06	Deceleration Overvoltage	Overvoltage suppression settings improper

2. Troubleshooting Process

1. Identify the Fault: Locate the cause based on the fault code.
2. Check Peripheral Devices: Inspect motors, cables, contactors, etc.
3. Adjust Parameters: Optimize overcurrent/overvoltage suppression settings.
4. Restart the Device: After resolving the fault, restart to confirm normal operation.

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IV. Conclusion

The Koreachuan KRC9 series inverter is a high-performance and reliable device suitable for various industrial applications. By mastering the operation panel functions, parameter settings, external control, and fault handling, users can fully leverage its capabilities and enhance productivity. This guide aims to provide practical references for the use and maintenance of the device.

I. Introduction to the Operation Panel Functions and Basic Settings of the Inverter

The ADLEEPOWER AS series inverter is a high-performance, multifunctional inverter with an intuitive operation panel and rich features. The operation panel mainly includes the following function keys:

• FWD/RUN: Forward run key. Pressing this key will rotate the motor in the forward direction.
• REV/RUN: Reverse run key. Pressing this key will rotate the motor in the reverse direction.
• SHIFT: Shift key. Used to switch the position of digits during parameter setting.
• UP/DOWN: Up/down keys. Used to increase or decrease values during parameter setting.
• PROG: Memory key. Used to save the currently set parameters.
• FUNC: Function key. Used to select the function to be set.
• STOP: Stop key. Pressing this key will stop the motor and return it to standby mode.

Restoring Factory Default Parameters

To restore the inverter’s parameters to factory defaults, follow these steps:

1. Press the PROG key to enter parameter setting mode.
2. Use the UP/DOWN keys to find the CD52 parameter (regional version).
3. Press the FUNC key to enter parameter modification mode.
4. Use the UP/DOWN keys to set the CD52 parameter to USA (for the US version) or Eur (for the European version), then press the PROG key to save.
5. Power off and restart the inverter. The parameters will be restored to factory defaults.

Setting and Removing Passwords

The AS series inverter supports password protection to prevent unauthorized parameter modifications. To set a password, follow these steps:

(Note: The specific password setting method may vary depending on the model. The following are general steps.)

1. Enter parameter setting mode.
2. Find the parameter related to password setting (refer to the user manual of the specific model for the exact parameter number).
3. Use the UP/DOWN keys to set the password, then press the PROG key to save.

To remove the password, simply set the password parameter to the default value or leave it blank.

Setting Parameter Access Restrictions

The AS series inverter also supports parameter access restriction functions, which can limit users’ access and modification permissions for certain parameters. To set parameter access restrictions, follow these steps:

1. Enter parameter setting mode.
2. Find the parameter related to parameter access restrictions (refer to the user manual of the specific model for the exact parameter number).
3. Use the UP/DOWN keys to set the access level, then press the PROG key to save.

II. Terminal Forward/Reverse Control and External Potentiometer Frequency Setting for Speed Regulation

Terminal Forward/Reverse Control

The AS series inverter supports forward/reverse control of the motor through external terminals. The specific wiring and parameter settings are as follows:

• Wiring:
  • Connect the forward control signal terminal of the external control signal to the FWD terminal of the inverter.
  • Connect the reverse control signal terminal of the external control signal to the REV terminal of the inverter.
  • Ensure that the common terminal of the external control signal is connected to the COM terminal of the inverter.
• Parameter Settings:
  • Enter parameter setting mode.
  • Find the CD12 parameter (terminal or keyboard selection).
  • Set the CD12 parameter to 1, indicating that the forward/reverse control of the motor is through the terminals.

External Potentiometer Frequency Setting for Speed Regulation

The AS series inverter also supports speed regulation by setting the frequency through an external potentiometer. The specific wiring and parameter settings are as follows:

• Wiring:
  • Connect the signal output terminal of the external potentiometer to the FA1 or FA2 terminal of the inverter (the specific terminal to be used depends on the parameter setting).
  • Ensure that the common terminal of the external potentiometer is connected to the GND terminal of the inverter.
• Parameter Settings:
  • Enter parameter setting mode.
  • Find the CD10 parameter (analog or digital setting).
  • Set the CD10 parameter to 1, indicating that the frequency is set through an analog signal (i.e., an external potentiometer).
  • Set the CD44 or CD45 parameter (multi-function analog FA1 or FA2 setting) as needed to select the FA1 or FA2 terminal as the frequency setting input terminal.

III. DC BR Fault Analysis and Solution

Meaning of DC BR Fault

When the AS series inverter displays a “DC BR” fault, it usually indicates a DC braking fault. DC braking is a function of the inverter that injects DC current into the motor during shutdown to quickly decelerate or stop the motor. If there is a problem with the DC braking circuit, it may cause a “DC BR” fault.

Possible Causes of the Fault

1. Damage to the DC Braking Resistor: The DC braking resistor is an important component in the DC braking circuit. If the resistor is damaged or aged, it may cause abnormal braking current, triggering the fault.
2. Failure of the Braking Transistor: The braking transistor is responsible for controlling the on/off of the DC braking current. If the transistor is damaged or its performance degrades, it may also cause a braking fault.
3. Improper Parameter Settings: If the parameters related to DC braking (such as braking time, braking current, etc.) are set improperly, it may result in poor braking performance or trigger a fault.

Solutions

1. Check the DC Braking Resistor: Use a multimeter or other tools to check the resistance value of the DC braking resistor. If the resistor is damaged or aged, replace it with a new one.
2. Check the Braking Transistor: Use a multimeter or other tools to check the performance of the braking transistor. If the transistor is damaged or its performance degrades, replace it with a new one.
3. Check Parameter Settings: Recheck whether the parameters related to DC braking are set correctly. Adjust the parameter values according to the actual situation of the motor and braking requirements.
4. Contact Technical Support: If the above methods cannot solve the problem, it is recommended to contact the technical support team or professional maintenance personnel of ADLEEPOWER inverters for further inspection and repair.

IV. Conclusion

The ADLEEPOWER AS series inverter, as a high-performance, multifunctional inverter product, has been widely used in the field of industrial automation. Through the introduction in this guide, users can better understand the operation panel functions, basic setting methods, terminal control and external speed regulation functions, as well as fault solution methods of the inverter. It is hoped that this guide can provide help and guidance to users when using the AS series inverters.

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The Hilectro HI300 series servo system is a high-performance servo drive widely used in industrial automation, renowned for its high precision and reliability. However, in practical applications, the fault code “Er050” may occur. This article provides a detailed analysis of the meaning of the “Er050” fault, its causes, as well as on-site inspection, handling, and specific maintenance methods to help technicians quickly restore equipment operation and summarize preventive measures to reduce the occurrence of similar faults.

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1. Meaning of Er050 Fault

In the Hilectro HI300 series servo system, the “Er050” fault code indicates Software Overcurrent. This is a protective mechanism triggered when the servo drive’s software detects that the current value exceeds the preset safety threshold. Unlike hardware overcurrent (such as “Er056”), “Er050” is primarily detected and alarmed by software algorithms, usually related to control parameters, feedback signals, or external wiring issues. When this fault occurs, the system stops running and displays “Er050” on the digital display, accompanied by related indicator lights (such as “RDY” or “VCC”) lighting up, prompting the operator to take action.

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2. Causes of Er050 Fault

The occurrence of “Er050” is not due to a single reason but is the result of multiple potential issues. The common causes are as follows:

1. Excessive Current Loop PI Parameters
   The current control of the servo system relies on a Proportional-Integral (PI) controller, adjusted through parameters such as proportional gain (Kp, typically corresponding to CI.00) and integral gain (Ki, typically corresponding to CI.02). If these parameters are set too high, the controller may overreact to current changes, causing current fluctuations to exceed the normal range and trigger the software overcurrent protection.
2. Short Circuit or Grounding on the Motor Output Side
   A short circuit in the motor’s internal windings or a ground fault in the output cable can cause a sharp increase in current. The software detects this anomaly and immediately alarms to protect the drive and motor.
3. Encoder Wiring Issues
   The encoder provides feedback on the motor’s position and speed. If the encoder wiring is loose, disconnected, or short-circuited, the servo system cannot accurately obtain feedback data, leading to current control instability and eventually causing an overcurrent fault.
4. Incorrect Motor Parameter Settings
   The servo drive needs to be precisely controlled based on the motor’s electrical parameters (such as inductance Ls). If the parameter configuration does not match the actual motor, the drive may output incorrect current commands, resulting in overcurrent.
5. Environmental or Power Supply Interference
   Power supply voltage fluctuations or high ambient temperatures may affect current stability. Especially under long-term operation or harsh conditions, the software may misjudge it as overcurrent.

These causes may interact with each other. For example, an encoder fault may lead to current control errors, which in turn amplify the impact of PI parameters, ultimately triggering “Er050.”

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3. On-Site Inspection and Handling Methods

When the equipment displays “Er050,” technicians need to follow a systematic inspection process to quickly identify the problem and take preliminary measures. The specific steps are as follows:

1. Check Current Loop Parameters

• Operation Method: Use the servo drive’s control panel or host computer software to enter the parameter setting interface and check the values of current loop parameters (such as CI.00 and CI.02).
• Judgment Standard: If the parameter values are significantly higher than the recommended range (refer to the equipment manual), it may be the cause of the fault.
• Handling Measures: Gradually reduce the Kp and Ki values (recommended to adjust by 10%-20% each time), save the settings, restart the system, and observe if the fault is resolved.

2. Check Motor Insulation and Wiring

• Operation Method: Turn off the power and wait for the capacitor to discharge (about 5-10 minutes). Use a multimeter or insulation resistance tester to measure the insulation resistance between motor phases and to ground.
• Judgment Standard: The normal insulation resistance should be greater than 10MΩ. If it is lower, it indicates a short circuit or grounding.
• Handling Measures: Inspect the motor cables and terminals, repair or replace damaged parts.

3. Check Encoder Wiring

• Operation Method: Ensure the encoder cable connections are secure and the shielding is properly grounded. Use a multimeter to test the continuity of the lines or an oscilloscope to observe the feedback signal waveform.
• Judgment Standard: Signal interruption or abnormal waveform (such as excessive noise) indicates an encoder fault.
• Handling Measures: Tighten loose connectors or replace damaged cables.

4. Check Motor Parameters

• Operation Method: Verify the motor parameters set in the drive (such as inductance Ls) against the motor nameplate or manual data.
• Judgment Standard: Significant parameter deviations may be the cause of the fault.
• Handling Measures: Correct the parameters based on the actual motor data, save, and test.

5. Environmental and Power Supply Check

• Operation Method: Use a voltmeter to measure the stability of the input power supply (380V-480V) and check the temperature and ventilation inside the control cabinet.
• Judgment Standard: Voltage fluctuations exceeding the standard (±10%) or high temperatures (>40°C) may cause faults.
• Handling Measures: Install a voltage stabilizer or improve cooling conditions.

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4. Specific Maintenance Recommendations

Based on the on-site inspection results, take the following targeted maintenance measures:

1. Parameter Adjustment
   If the PI parameters are too large, gradually reduce the values of CI.00 and CI.02, testing after each adjustment to observe the system response. Avoid excessive reduction that may lead to control instability.
2. Wiring Repair
   For encoder or motor wiring issues, tighten loose connectors or replace damaged cables. Ensure the shielding is properly grounded to reduce electromagnetic interference.
3. Component Replacement

• Motor Fault: If insulation tests show a short circuit or grounding, replace the motor or repair the insulation.
• Encoder Damage: Replace with the same model encoder and recalibrate the system.

1. Hardware Maintenance
   If internal current sensors or power modules (such as IGBT) are suspected to be faulty, have a professional inspect and possibly replace the damaged components.
2. Safety Operations
   Ensure the power is off and capacitors are discharged before maintenance. Use insulated tools and protective equipment. If the issue is complex, contact Hilectro technical support with the serial number and fault details for guidance.

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5. Preventive Measures and Routine Maintenance

To prevent the recurrence of “Er050” faults, implement the following preventive measures:

1. Regular Inspections
   Check motor, encoder, and power supply wiring quarterly to ensure there is no looseness or aging.
2. Parameter Management
   Regularly back up parameter settings and monitor current waveforms during operation to ensure they are within normal ranges.
3. Environmental Optimization
   Keep the control cabinet clean and dry, install ventilation or dehumidification equipment to prevent overheating and moisture accumulation.
4. Personnel Training
   Train operators to recognize early anomalies (such as motor noise or overheating) and report them promptly for handling.

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6. Conclusion

The “Er050” fault in the Hilectro HI300 series servo system, indicating software overcurrent, is a common protective alarm typically caused by excessive current loop parameters, wiring faults, or incorrect motor parameters. Through systematic on-site inspections (such as parameter verification, insulation testing, and encoder checks) and targeted maintenance (such as adjusting parameters or replacing components), technicians can effectively resolve the issue. Preventive maintenance and a deep understanding of the fault mechanisms are key to ensuring long-term stable operation of the equipment. We hope this article provides practical guidance for on-site operations. For further assistance, refer to the equipment manual or contact professional technical support.

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