Category: KEB

I. Overview (Introduction)

In industrial drive equipment, the KEB COMBIVERT F5 series inverter is widely used in injection molding machines, elevators, and automation equipment. This series is renowned for its high stability and rich programmable functions. However, precisely due to its complexity, the prompt messages for different types of faults and the error evolution logic often confuse maintenance personnel during drive debugging and repair.

This article takes a real on – site fault as a clue, systematically sorting out the fault causes, parameter checks, and handling procedures from the initial E.OH (power module overheating) → subsequent recovery state E.nOH → E.H496 (extended error code) after replacing the motherboard. It also summarizes a standard troubleshooting logic to help you locate problems more efficiently.

II. Drive Model and Hardware Background

• Model: KEB COMBIVERT F5 series (e.g., MAT.NO example: 23F5A1R – YVC2)
• Power rating: Approximately 75 kW, with an input of 400V AC three – phase, 165A; an output supporting a frequency range of 0 – 800 Hz, and a maximum current of about 150 A (UL 136A)
• Control board and power board combination: The drive unit is composed of an F5 – General or F5 – Basic control board in combination with a power module. The structured hardware connection is stable.
  This system has undergone initial power – on, multiple fault resets, and motherboard replacement, eventually entering a complex error stage.

III. Stage 1: Initial Fault – E.OH (Power Module Overheating)

When the variable – frequency drive detects that the temperature of the power module (heat sink) is too high, it triggers the E.OH error, and at this time, the drive shuts off the output to protect the module. Such errors are often caused by:

• Blocked or failed cooling fans
• Severe dust accumulation on the heat sink
• Excessively high ambient temperature
  According to the documentation (TRD Error codes / KEB F5 manual):
• For E.OH, one must wait for the internal temperature to drop by at least 3 °C before entering the reset stage.
• The drive displaying E.nOH indicates that the overheating state has been lifted, and the power module has cooled to a safe level.
  Maintenance operations include:
• Powering off and waiting for cooling
• Cleaning the fans and heat sink
• Checking and improving the ambient ventilation

IV. Stage 2: From E.nOH to Replacing the Control Board

The E.nOH state confirms that the drive has returned to normal. Everything operates normally for a short period.
If the control motherboard is then replaced (e.g., replacing an old faulty board or upgrading the firmware), it may change the internal identification of the drive.
If the drive’s main control board and power board do not correctly match the firmware or power unit identification parameters at this time, new advanced errors may be triggered.

V. Stage 3: E.H496 – Advanced Extended Error Code After Replacing the Motherboard

1. What is E.H496?

E.H496 belongs to the advanced error code (extension error class), specifically indicating a communication or identification anomaly between the control board and the power unit.
In the KEB error manual, it is classified as “power unit changed” or “EEPROM configuration mismatch”. The error prompts may appear in forms such as E.PUCH, E.PUCH, etc., but some new firmware versions may display it as H496.

2. Cause Analysis

• The control board detects a change in the power unit identification number but the parameters are not synchronized.
• The power unit configuration saved in the EEPROM does not match.
• Inconsistent firmware versions lead to a failure in the parameter group SY.3 checksum.
• The physical connection between the control board and the power board is loose or the communication lines are loose.

VI. Standard Troubleshooting and Handling Procedures 🧭

Step 1: Check the Error History

• Set the parameter Ud.00 = 660 to enable the LF error log function.
• View the 0.LF.98 log to analyze the error generation time, type, and sequence.

Step 2: Verify the Connection between the Control Board and the Power Board

• Check whether the ribbon cables of the X interface are secure and free of oxidation.
• If there is dust or poor contact, clean and re – plug them.

Step 3: Confirm EEPROM and Firmware Matching

• Compare the firmware versions of the new and old motherboards with the power board version.
• If the drive prompts “power unit changed”, write the displayed power unit identification code into the parameter group SY.3 for confirmation.
• If the SY.3 parameter is written incorrectly, the system will load default values or lock the startup.

Step 4: Perform Synchronization and Initialization

• If there is an identification anomaly after replacing the control board, write the correct value of SY.3 according to the manual and only reload the power – related parameters.
• If it still fails, write other values to perform a complete parameter reload (load the KEB default set) and restart the drive.
• After completing the operations, it is recommended to restart the system (Power – on reset) to ensure synchronization between the drive board and the power module.

Step 5: Re – check Thermal Management and Hardware Status

• After cooling, power on again to ensure that the fans are working and the ambient temperature is reasonable.
• Avoid the recurrence of E.OH, which may affect subsequent diagnosis.

VII. Summary Table of Fault Evolution Logic

Stage	Display Code	Meaning	Possible Causes	Main Handling Measures
Initial	E.OH → E.nOH	First overheating of the power module and return after cooling	Poor heat dissipation, high ambient temperature	Clean the fans and heat sink, improve ventilation
Intermediate	E.nOH state returns to normal	No new errors in the module	Temporary parameter recovery process	No additional operations required
After replacing the motherboard	E.H496 or E.PUCH	Advanced error: Power unit identification anomaly	Control board/firmware mismatch, identification code change, communication error	Rewrite SY.3, check communication, re – initialize parameters

VIII. Recommended Further Operation Plans and Prevention Points

• Record the LF error log
  Save the LF.98 content completely before and after state switching to facilitate tracing the root cause of errors.
• Synchronize parameter groups after replacing the motherboard
  Especially for SY.3 and related LF/enc parameters, confirm that the motherboard and power module are properly matched.
• Fan and ventilation maintenance
  Regularly maintain the cooling system to avoid long – term dust accumulation and overheating faults.
• Perform encoder reset and learning (if applicable)
  If there has been a recent replacement of the encoder card or a change in the feedback interface, check parameters such as LF.26 and LF.27 and re – execute the automatic learning process (refer to the previous handling of E.HYBc – type errors).
• Collaborate with KEB technical support if necessary
  If the firmware version is unclear or the error code is ambiguous, provide information such as SY.3 / LF.98 to KEB support engineers for targeted guidance.

IX. Conclusion

The process from E.OH (power module overheating) → recovery to E.nOH → entering the E.H496 advanced error after replacing the motherboard actually reflects the strong mechanism of KEB drives for hardware identification and power unit consistency verification. Reasonable understanding and operation according to the standard procedures can minimize the fault recovery time and improve equipment stability.

The KEB F5 series inverters are versatile and powerful devices used widely across industries for motor control and energy efficiency. This guide consolidates essential instructions and insights from various manuals to provide a comprehensive reference for daily operation, including starting, stopping, speed control, and troubleshooting.

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1. Overview of Common Usage Methods

1.1 Starting and Stopping the Inverter

To ensure safe and effective operation, follow these steps:

• Startup Procedure:
• Connect the power supply as per the wiring instructions in the manual.
• Ensure all safety interlocks and protective devices are active.
• Use the control panel or external start/stop commands to initiate the inverter.
• Check the display for proper status indications (e.g., “Run” mode).
• Stopping Procedure:
• Use the stop button on the control panel or external command inputs.
• Ensure the motor decelerates smoothly to prevent mechanical stress.
• Verify that the inverter returns to “Stop” mode on the display.

1.2 Speed Control and Parameter Adjustment

The F5 series supports flexible speed control via:

• Analog Inputs: Use a potentiometer or external signal to set the desired speed. Adjust parameters such as AN1 and AN2 for signal scaling.
• Digital Inputs: Configure fixed speeds via digital input terminals (e.g., X2A.10 and X2A.11) as per the CP parameters.
• Control Panel: Manually set speeds through the operation keypad by navigating to the appropriate menu.
• Ramp Settings: Configure acceleration and deceleration times (e.g., CP.20 and CP.21) to suit the application.

1.3 Protective Functions

The inverter includes several built-in protection mechanisms, such as:

• Overcurrent (E.OC)
• Overvoltage (E.OP)
• Overload (E.OL)
• Motor overtemperature (E.OH)

These features safeguard both the inverter and the connected motor, ensuring reliable operation.

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2. Troubleshooting Common Faults

The F5 series displays fault codes on the control panel to assist with diagnostics. Below are some frequently encountered errors and their solutions:

2.1 Fault Code List and Remedies

• E.OC (Overcurrent):
• Cause: Excessive load or short circuit in the motor.
• Solution: Check the motor connections and reduce the load if necessary. Inspect and replace damaged cables.
• E.OP (Overvoltage):
• Cause: Excessive regeneration energy from the motor.
• Solution: Increase deceleration time or add an external braking resistor.
• E.OL (Overload):
• Cause: Prolonged operation beyond the inverter’s capacity.
• Solution: Allow the inverter to cool and check motor power ratings.
• E.OH (Overheat):
• Cause: Inadequate cooling or excessive ambient temperature.
• Solution: Improve ventilation and clean cooling fans and filters.

2.2 Diagnostic Features

The “ru” parameter group provides real-time operating data:

• ru.0: Inverter status
• ru.1: Input frequency
• ru.2: Output frequency
• ru.18: DC bus voltage
• ru.39: Overload timer

Use these values to monitor performance and identify abnormalities.

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3. Practical Tips for Optimal Performance

3.1 Parameter Group Adjustments

• Use the CP parameter group for configuration, covering essential settings like input/output scaling, motor control modes, and protection thresholds.
• Advanced users can access additional settings in the “In” and “Sy” groups for specialized applications.

3.2 Wiring and Installation Considerations

• Ensure proper grounding and shielded cables to minimize electromagnetic interference (EMI).
• Keep control cables and power cables separate to avoid cross-talk.
• Verify that terminal connections (e.g., X2A, X3A) match the manual’s specifications.

3.3 Regular Maintenance

• Inspect cooling fans, filters, and vents regularly to prevent overheating.
• Check all connections periodically for looseness or corrosion.
• Update firmware as recommended by KEB to ensure compatibility and reliability.

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4. Recommended Applications and Limitations

4.1 Suitable Applications

The F5 series is ideal for:

• Industrial motor control (e.g., conveyors, pumps, fans).
• Precision speed and torque control.
• Energy savings in variable load applications.

4.2 Limitations

• Not designed for non-motor electrical loads.
• Requires proper environmental conditions (e.g., temperature, humidity) as specified in the manual.

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Conclusion

The KEB F5 series inverters are versatile tools that offer reliable performance across diverse applications. By following this guide, users can achieve smooth operation, effective speed control, and swift resolution of common issues. For advanced settings or complex troubleshooting, refer to the detailed manual or consult KEB’s technical support.

The KEB F5 series inverters are high-performance devices widely used in industrial applications. Their powerful control capabilities and flexible configurations allow them to meet diverse and complex requirements. Within the F5 series, model suffixes often indicate specific functions and configurations. This article analyzes the similarities and differences between the 15F5C1E-YC3A and 15F5C1E-Y50A models and explores their interchangeability in practical applications.

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1. In-Depth Analysis of Model Specifications

KEB inverters follow a specific naming convention comprising two parts: the base model (e.g., 15F5C1E) and the suffix (e.g., YC3A or Y50A). The base model describes the core functionality of the device, such as power range, control type, and motor compatibility, while the suffix indicates specific configurations or application scenarios.

1. Base Model

• 15F5C1E represents:
• 15: Power unit specification, typically related to output current or power rating.
• F5: KEB F5 series, representing a versatile inverter series.
• C1E: Control logic and hardware characteristics, possibly related to control card type or hardware interfaces.

The two models share the same base model, meaning they are identical in terms of power range, core control logic, and hardware.

2. Differences in Suffixes

• YC3A and Y50A represent specific configuration differences. Based on the KEB inverter manual and general naming conventions, these differences likely include:
• Y: Typically indicates control logic type or industry-specific applications.
• C3 vs. 50:
  • C3: Likely refers to an integrated C3-grade electromagnetic compatibility (EMC) filter, which reduces electromagnetic interference (EMI) in industrial environments. C3-grade filters are suitable for high-EMC-requirement scenarios, such as production lines with sensitive electronic equipment.
  • 50: May represent a standard configuration without a built-in C3 filter, suitable for general-purpose applications with lower EMC requirements or cost sensitivity.
• A: Often denotes additional features, such as regional adaptations, industry-standard compliance, or extra hardware configurations.

Based on the analysis, 15F5C1E-YC3A offers higher EMC adaptability and is better suited for high-demand industrial environments, whereas 15F5C1E-Y50A is positioned as a general-purpose model with potentially lower costs and broader applicability.

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2. Conditions for Interchangeability

While 15F5C1E-YC3A and 15F5C1E-Y50A share the same basic functionality, their suffixes indicate configuration differences that affect interchangeability. Below is a detailed analysis:

1. Scenarios Where They Can Be Interchanged

• Low EMC Requirements: In scenarios without stringent EMC demands, such as general industrial equipment drives, 15F5C1E-YC3A and 15F5C1E-Y50A can be interchanged.
• Identical Power Parameters: Both models share the same core hardware (e.g., power units and control cards), ensuring no difference in motor drive performance, power range, or current output.
• No Need for Built-In Filters: If the environment lacks significant electromagnetic interference or external EMI filters are already installed, either model can be selected.

2. Scenarios Where Interchangeability Is Not Recommended

• High EMC Requirements: In environments with sensitive electronic devices or stringent EMC standards (e.g., medical devices or laboratory instruments), 15F5C1E-YC3A should be preferred for its built-in C3 filter.
• Industry-Specific Standards: Certain industries, such as automotive manufacturing or aerospace, may require equipment to meet specific EMC standards, making YC3A the appropriate choice.
• Reducing Commissioning Complexity: The integrated filter design of 15F5C1E-YC3A minimizes the need for external filters, simplifying installation and commissioning.

3. Parameter Adjustments and Compatibility Checks

If interchangeability is necessary, the following steps are recommended:

• Verify Input and Output Voltage Ranges: Ensure that the voltage ranges of both devices match the application requirements.
• Conduct EMC Compatibility Tests: Perform on-site EMC tests during replacement to ensure no interference with other equipment.
• Align Parameter Settings: Use the KEB inverter’s parameter adjustment features to match the new device’s operating parameters with the previous one.

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3. Conclusion and Recommendations

Based on the analysis, 15F5C1E-YC3A and 15F5C1E-Y50A are identical in terms of core hardware and control logic, but their suffixes reflect configuration differences, primarily in EMC compatibility and industry adaptability.

• YC3A is suitable for industrial scenarios with high EMC requirements, especially where electronic devices are prevalent or electromagnetic interference must be minimized.
• Y50A is better suited for general-purpose applications, offering a cost-effective option.

In practice, these models can be interchanged under certain conditions, but users should choose based on specific application requirements. Replacing Y50A with YC3A in EMC-sensitive environments poses no compatibility concerns, whereas the reverse may require additional EMC testing to ensure safe operation.

Ultimately, selecting the correct model involves more than cost considerations; it requires a comprehensive evaluation of the application environment, EMC needs, and commissioning complexity. It is advisable to consult KEB technical support or refer to the product manual before implementation to ensure the chosen device fully meets the application requirements.