Month: March 2025

M900 Inverter err64 Fault: Meaning, Root Cause Analysis, and Solutions

(This article discusses the background of the “err64” fault in M900 series inverters, its potential causes, deeper hardware-level analyses, and practical troubleshooting steps. The goal is to help electrical maintenance personnel target the problem more effectively. This text, of over 1,000 words in its Chinese original, covers both theoretical and hands-on repair perspectives.)

I. Background and Meaning of err64

In typical inverter applications, the most common faults involve overcurrent, overvoltage, undervoltage, overload, and cooling fan issues. However, in certain cases—especially after repairs or the replacement of internal components—M900 inverters may display a “err64” fault code. According to the manufacturer’s technical support, “err64” is not listed in the usual user manual but indicates a communication failure between the main control board and the driver board.

In other words, the inverter’s primary control circuitry (often referred to as the “master” or “main” board) and its power drive unit (“driver” board) cannot exchange data, causing the control system to fail to operate properly and thus triggering a fault protection.

To understand this issue, one must note that an M900 inverter typically consists of at least two major sections: a control board (hosting the microcontroller or DSP as the core of the logic) and a driver board (housing the power modules, IGBTs, or related gate driver circuitry). These boards communicate via a dedicated interface or set of pins. Sometimes, there may also be a small power supply board or other auxiliary boards, but the communication link between the main board and the driver board is central to the entire system. Once that link is broken or corrupted, the inverter will report a “board-to-board communication error” such as “err64” and shut down to protect itself.

II. Common Causes of err64

1. Loose or Faulty Ribbon Cable/Connector
   During maintenance or reassembly, a ribbon cable or connector might not have been fully seated, or its metal pins could be bent, oxidized, or otherwise damaged. This often leads to poor signal transmission or no transmission at all, and is one of the most frequent root causes for communication errors.
2. Damaged Hardware Chips
   • Burned-out Transceiver/Bus Chip: The communication between the control and driver boards usually involves specialized transceiver components (e.g., RS485 driver chips, optical isolators, or TTL level transceivers). If subjected to excessive heat, current surge, or electrostatic discharge, these chips can fail and interrupt the data link.
   • Main CPU or Driver DSP Failure: Though less common, serious power surges, extended over-temperature conditions, or short-circuit mishandling can damage the main controller or DSP on either board. When that happens, the inverter can no longer exchange valid data, triggering the err64 alarm.
3. Auxiliary Power Supply Issues
   The main board and driver board typically rely on a regulated power supply—often +5V or +3.3V—to operate their digital circuits. If this low-voltage supply is weak or unstable, or if a regulator (LDO, DC-DC converter) on either board is failing, then even intact chips may produce garbled signals and fail to establish proper communication.
4. Secondary Damage During Fan or Relay Replacement
   Many reported err64 errors occur soon after a user replaces a fan or relay. This suggests that the process may introduce secondary problems:
   • An incompatible relay or altered circuit parameters causing abnormal power conditions;
   • Accidental short-circuits or soldering damage during the repair;
   • The inverter may already be partially degraded from prior overheating, so additional stress completes the failure pathway.

III. Root Cause Analysis and Troubleshooting

At its core, “err64” represents an internal communication failure. This communication is usually a low-level or custom protocol rather than a typical external fieldbus (like Modbus). As a result, the inverter’s diagnostic does not offer many granular details. Because the issue can lie in various hardware points, it is best to follow a structured approach:

1. Physical Inspection and Connector Checks
   • First, turn off power and wait long enough for internal capacitors to discharge (generally at least 10 minutes).
   • Open the inverter casing to inspect all connectors, paying particular attention to the flat cables and sockets between the main board and driver board. Look for signs of looseness, oxidation, broken plastic housings, or bent pins.
   • Clean off any dust or grime with an appropriate solution such as isopropyl alcohol. Dry thoroughly, re-seat the connectors firmly, then restart and see if the error persists.
   • This preliminary step is simple but can resolve many “false” faults that arise after vibrations or reassembly.
2. Supply Rails and Signal Tests
   • Use a multimeter to check the low-voltage rails (+5V, +3.3V, etc.) on both the control and driver boards. Confirm stable, correct output levels.
   • If available, use an oscilloscope to observe the communication pins (TX, RX, or RS485 differential signals) for pulses or signals. If the line is held at a steady voltage with no pulses, it indicates that the transmitter is not functioning (which could mean the transceiver or even the CPU is compromised).
   • If the signal is noisy or the amplitude is too low, consider the possibility of defective coupling resistors, capacitors, or the transceiver chip itself.
3. Suspecting Transceiver or MCU Failure: The Swap/Replacement Method
   • After verifying connectors, supply rails, and passive components, you may try replacing the communication transceiver chip with one of the same model if you suspect it is burned out.
   • If replacing the transceiver chip does not help, the fault may lie in the main CPU, driver DSP, or other major components on the board. Diagnosing or replacing these can require specialized tools and is best handled by trained professionals.
4. Reset to Factory Defaults or Firmware Update
   • Occasionally, firmware or software anomalies can also trigger internal communication timeouts.
   • Attempt a factory reset (restoring default parameters) and then power up again to see if the fault clears. If the manufacturer provides a firmware update procedure, you can try upgrading the system firmware. However, if the hardware is physically damaged, these software-level attempts typically will not resolve an err64 alarm.

IV. Precautions and Preventive Measures

1. Prompt Cooling System Maintenance
   If the M900 inverter’s cooling fan stops working or its venting is blocked, the internal boards can operate at high temperatures, accelerating aging. Quick repair or replacement of fans can prevent serious damage that leads to communication issues.
2. Standardized Repair Operations
   • Always allow adequate discharge time after powering off the inverter to avoid electric shock or component damage.
   • When replacing a relay or other parts, match the specifications (coil voltage, contact ratings, etc.) exactly.
   • Proper soldering tools and techniques are crucial—poorly done solder joints or bridging can damage sensitive PCB traces and components.
3. Cleanliness and Protective Practices
   • In dusty or humid environments, regularly open the inverter casing for an internal check and cleaning.
   • If connectors or components show corrosion or rust, replace or clean them promptly.
   • Perform these repairs or inspections in as clean an environment as possible, avoiding metal particles, oil, or fine dust contamination on open circuit boards.
4. Fault Log and Data Recording
   • If the inverter can store internal logs or provide real-time data, document those details as soon as a fault appears.
   • Observing the inverter’s normal operating waveforms versus the state just before a failure can guide you to the precise area of malfunction.

Conclusion

In summary, an M900 inverter reporting “err64” indicates a lost or compromised communication link between its main control board and driver board. This can stem from something as simple as a partially inserted ribbon cable or can be as severe as a failed bus transceiver chip or main CPU.

The recommended troubleshooting approach is systematic:

1. Inspect and re-seat cables and connectors;
2. Verify supply voltages and signals;
3. Replace suspect transceiver and check associated passive parts;
4. Finally, if those attempts fail, look toward the main CPU, DSP, or more advanced board-level repairs.

Meanwhile, ensuring proper cooling, following proper service procedures, and regularly cleaning the inverter’s internals will significantly lower the likelihood of such communication failures. If all methods are exhausted, contacting a professional repair center or the manufacturer is advisable for advanced diagnostics. By fully understanding the root cause and progression of “err64” faults, you can remedy them swiftly and maintain the M900 inverter’s reliability for critical industrial processes.

The JTE Inverter JT26N series is a high-performance general-purpose inverter widely used in various industrial control scenarios. This article provides a detailed introduction to the usage of this inverter, including panel startup and speed adjustment settings, external terminal forward/reverse and external potentiometer speed adjustment settings, parameter copying and initialization methods, as well as the meaning and resolution of the ERR10 fault.

I. Basic Settings for the JTE Inverter JT26N

1. Panel Startup and Speed Adjustment Settings

The panel startup and speed adjustment settings for the JTE Inverter JT26N are relatively straightforward. Users can complete basic startup and speed adjustment operations through the buttons and display on the control panel. Here are the specific steps:

1. Startup Settings:

• Press the “PRGM” key to enter programming mode.
• Use the “Δ” and “∇” keys to select the function code F0-02, and confirm that the command source is set to the control panel command channel (value 0).
• Press the “ENTER” key to confirm the setting.

1. Speed Adjustment Settings:

• In programming mode, select the function code F0-03 and set the main frequency source X to panel potentiometer speed adjustment (value 1).
• Adjust the frequency by rotating the potentiometer on the panel to achieve speed control.

2. External Terminal Forward/Reverse and External Potentiometer Speed Adjustment Settings

The JTE Inverter JT26N supports forward/reverse control and external potentiometer speed adjustment functions through external terminals. Here are the specific wiring and setup methods:

1. Forward/Reverse Control:

• Wiring: Connect the external control signal to the digital input terminals of the inverter (such as MI1, MI2, etc.).
• Settings: In programming mode, select the function code F0-09 and set the running direction to forward (value 0) or reverse (value 1).

1. External Potentiometer Speed Adjustment:

• Wiring: Connect the signal line of the external potentiometer to the analog input terminals of the inverter (such as AI1, AI2, etc.).
• Settings: In programming mode, select the function code F0-03 and set the main frequency source X to external potentiometer speed adjustment (value 2, 3, or 4, depending on the specific terminal).

II. Parameter Copying and Initialization

1. Parameter Copying

The JTE Inverter JT26N supports parameter copying, allowing users to copy parameters from one inverter to another. Here are the specific steps:

1. Prepare a blank storage card or USB drive and insert it into the parameter copying interface of the inverter.
2. Press the “PRGM” key to enter programming mode and select the parameter copying function.
3. Follow the prompts to copy the parameters to the storage card or USB drive.
4. Insert the storage card or USB drive into another inverter and follow the prompts to copy the parameters to the new inverter.

2. Parameter Initialization

In some cases, users may need to initialize the inverter parameters. Here are the specific steps:

1. Press the “PRGM” key to enter programming mode.
2. Select the function code F0-27 and set the parameter initialization option to fully initialize parameters (value 03).
3. Press the “ENTER” key to confirm, and the inverter will reset to factory settings.

III. Meaning and Resolution of the ERR10 Fault

1. Meaning of the ERR10 Fault

The ERR10 fault is a common fault code for the JTE Inverter JT26N, indicating an overload condition. An overload occurs when the output current of the inverter exceeds its rated current, which may be caused by the following reasons:

1. The load is too large, exceeding the rated capacity of the inverter.
2. There is a mechanical fault in the motor or other load equipment, causing abnormal current increases.
3. The parameter settings of the inverter are incorrect, leading to overload protection activation.

2. Handling the ERR10 Fault

When the ERR10 fault occurs on-site, users should follow these steps to address it:

1. Check the Load: Ensure that the load is within the rated capacity range of the inverter, reducing the load if necessary.
2. Inspect the Motor and Equipment: Check the motor and other load equipment for mechanical faults, such as jamming or excessive resistance.
3. Verify Parameter Settings: Ensure that the inverter’s parameter settings are correct, especially those related to the load.
4. Restart the Inverter: After confirming that the load and equipment are normal, restart the inverter and observe if the ERR10 fault still occurs.

3. Repair Methods for the ERR10 Fault

When repairing the internal circuit board of the inverter after an ERR10 fault, users should follow these steps:

1. Inspect Under Power-Off Conditions: Open the inverter’s casing in a power-off state and inspect the internal circuit board for any visible damage or burnout.
2. Clean the Circuit Board: Use a clean cloth or cotton swab dipped in isopropyl alcohol to gently wipe the surface of the circuit board, removing dust and dirt.
3. Replace Damaged Components: If any damaged or burned components are found on the circuit board, replace them with new components of the same model.
4. Reassemble: After ensuring that the circuit board has no visible faults, reassemble the inverter and perform a functional test.

IV. Conclusion

The JTE Inverter JT26N is a powerful and easy-to-operate inverter suitable for various industrial control scenarios. By correctly setting up panel startup and speed adjustment, external terminal forward/reverse, and external potentiometer speed adjustment, users can easily achieve basic control functions of the inverter. Additionally, the inverter supports parameter copying and initialization functions, making it convenient for users to manage parameters. In the event of an ERR10 fault, users should promptly check the load and equipment and follow the correct procedures for handling and repair to ensure the normal operation of the inverter.