Hitachi WL200 Fault Codes & Troubleshooting List 2026 – Troubleshoot your Hitachi WL200 inverter with our updated 2026 guide. Learn to interpret E01-E60 trips, use ProDriveNext for advanced diagnostics, and reset faults efficiently.
The Hitachi WL200 is a versatile, compact inverter known for its high starting torque and built-in PLC-like logic functions (Easy Sequence). In 2026, it remains a popular choice for material handling and fan/pump applications. When the drive detects an abnormality, the 4-digit LED display flashes a trip code starting with “E” (e.g., E01, E07, E14).
This guide provides the most updated resources for 2026 to help you diagnose these error codes and get your machinery back into operation with minimal downtime.
WL200 Fault Codes Reference Table
Below is the complete list of protective functions and alarm codes for the WL200. Please refer to this table to match the alphanumeric code on your display with the specific hardware or load issue.
| Fault Code and Meaning | Cause and Remedy |
|---|---|
| E01 Over-current event while at constant speed | Cause: The inverter output was short-circuited, or the motor shaft is locked or has a heavy load. These conditions cause excessive current for the inverter, so the inverter output is turned OFF. Setting in dual-voltage motor is wrong. Remedy: Check for short circuits, unlock the motor shaft, or reduce load. Press Stop/Reset key. |
| E02 Over-current event during deceleration | Cause: Excessive current detected during deceleration. (Similar conditions to E01). Remedy: Check deceleration time parameters. Press Stop/Reset key. |
| E03 Over-current event during acceleration | Cause: Excessive current detected during acceleration. (Similar conditions to E01). Remedy: Check acceleration time parameters. Press Stop/Reset key. |
| E04 Over-current event during other conditions | Cause: Excessive current detected during conditions other than constant speed, accel, or decel. Remedy: Check motor and load conditions. Press Stop/Reset key. |
| E05 Overload protection | Cause: When a motor overload is detected by the electronic thermal function, the inverter trips and turns OFF its output. Remedy: Reduce motor load. Press Stop/Reset key. |
| E06 Braking resistor overload protection | Cause: When the BRD operation rate exceeds the setting of “b090”, this protective function shuts off the inverter output and displays the error code. Remedy: Check braking usage and “b090” setting. Press Stop/Reset key. |
| E07 Over-voltage protection | Cause: When the DC bus voltage exceeds a threshold, due to regenerative energy from the motor. Remedy: Check input voltage and deceleration times. Press Stop/Reset key. |
| E08 EEPROM error | Cause: When the built-in EEPROM memory has problems due to noise or excessive temperature, the inverter trips and turns OFF its output to the motor. Remedy: Reset operation by RS terminal or STOP/RESET key is not accepted. Reset by cycling power. If error persists, perform initialization. |
| E09 Under-voltage error | Cause: A decrease of internal DC bus voltage below a threshold results in a control circuit fault. This condition can also generate excessive motor heat or cause low torque. Remedy: Check input power source. Press Stop/Reset key. |
| E10 Current detection error | Cause: If an error occurs in the internal current detection system, the inverter will shut off its output and display the error code. Remedy: Press Stop/Reset key. If error persists, contact support. |
| E11 CPU error | Cause: A malfunction in the built-in CPU has occurred, so the inverter trips and turns OFF its output to the motor. Remedy: Press Stop/Reset key. |
| E12 External trip | Cause: A signal on an intelligent input terminal configured as EXT has occurred. The inverter trips and turns OFF the output to the motor. Remedy: Remove the external trip signal. Press Stop/Reset key. |
| E13 USP (Unattended Start Protection) | Cause: When the Unattended Start Protection (USP) is enabled, an error occurred when power is applied while a Run signal is present. Remedy: Clear the Run signal. Press Stop/Reset key. |
| E14 Ground fault | Cause: The inverter is protected by the detection of ground faults between the inverter output and the motor during powerup tests. Remedy: Reset operation by RS terminal or STOP/RESET key is not accepted. Check motor/cable for ground faults. Reset by cycling power. |
| E15 Input over-voltage | Cause: The inverter tests for input over-voltage after the inverter has been in Stop Mode for 100 seconds. If an over-voltage condition exists, the inverter enters a fault state. Remedy: Check input voltage. After the fault is cleared, the inverter can enter Run Mode again. |
| E19 Inverter thermal detection system error | Cause: When the thermal sensor in the inverter module is not connected. Remedy: Press Stop/Reset key. |
| E21 Inverter thermal trip | Cause: When the inverter internal temperature is above the threshold, the thermal sensor in the inverter module detects the excessive temperature of the power devices and trips. Remedy: Allow inverter to cool. Check cooling fans/ventilation. Press Stop/Reset key. |
| E22 CPU communication error | Cause: When communication between two CPU fails, inverter trips and displays the error code. Remedy: Press Stop/Reset key. |
| E25 Main circuit error | Cause: The inverter will trip if the power supply establishment is not recognized because of a malfunction due to noise or damage to the main circuit element. Remedy: Check power supply and for electrical noise. Press Stop/Reset key. |
| E30 Driver error | Cause: An internal inverter error has occurred at the safety protection circuit between the CPU and main driver unit. Excessive electrical noise may be the cause. Remedy: Reset operation by RS terminal or STOP/RESET key is not accepted. Reset by cycling power. |
| E35 Thermistor | Cause: When a thermistor is connected to terminals [5] and [L] and the inverter has sensed the temperature is too high. Remedy: Check thermistor temperature. Press Stop/Reset key. |
| E36 Braking error | Cause: When “01” has been specified for the Brake Control Enable (b120), the inverter will trip if it cannot receive the braking confirmation signal within the Brake Wait Time. Remedy: Check brake signal wiring and timing. Press Stop/Reset key. |
| E37 Safe Stop | Cause: Safe stop signal is given. Remedy: Check Safe Stop input. Press Stop/Reset key. |
| E38 Low-speed overload protection | Cause: If overload occurs during the motor operation at a very low speed, the inverter will detect the overload and shut off the inverter output. Remedy: Reduce load at low speeds. Press Stop/Reset key. |
| E40 Operator connection | Cause: When the connection between inverter and operator keypad failed. Remedy: Check keypad connection. Press Stop/Reset key. |
| E41 Modbus communication error | Cause: When “trip” is selected (C076=00) as a behavior in case of communication error, inverter trips when timeout happens. Remedy: Check Modbus communication lines. Press Stop/Reset key. |
| E43 EzSQ invalid instruction | Cause: The program stored in inverter memory has been destroyed, or the PRG terminal was turned on without a program downloaded to the inverter. Remedy: Check or reload EzSQ program. Press Stop/Reset key. |
| E44 EzSQ nesting count error | Cause: Subroutines, if-statement, or for-next loop are nested in more than eight layers. Remedy: Correct EzSQ program structure. Press Stop/Reset key. |
| E45 EzSQ instruction error | Cause: Inverter found the command which cannot be executed. Remedy: Correct EzSQ program command. Press Stop/Reset key. |
| E50 to E59 EzSQ user trip (0 to 9) | Cause: When user-defined trip happens, inverter trips and displays the error code. Remedy: Check user program logic. Press Stop/Reset key. |
| E60 to E69 Option error | Cause: The inverter detects errors in the option board mounted in the optional slot. For details, refer to the instruction manual for the mounted option board. Remedy: Refer to Option Board manual. Press Stop/Reset key. |
| H001 Frequency upper limit warning | Cause: Frequency upper limit (A061) > Max. Frequency (A004). Remedy: Correct parameter settings. |
| H002 Frequency lower limit warning | Cause: Frequency lower limit (A062) > Max. Frequency (A004). Remedy: Correct parameter settings. |
| H005 Multi-speed freq warning | Cause: Output Frequency setting (F001) or Multi-speed freq. 0 (A020) > Max. Frequency (A004). Remedy: Correct parameter settings. |
| H015 Frequency setting warning | Cause: Output Frequency setting (F001) or Multi-speed freq. 0 (A020) > Frequency upper limit (A061). Remedy: Correct parameter settings. |
| H025 Frequency lower limit conflict | Cause: Frequency lower limit (A062) > Output Frequency setting (F001) or Multi-speed freq. 0 (A020). Remedy: Correct parameter settings. |
| H031 Start frequency conflict | Cause: Start frequency (A082) > Frequency upper limit (A061). Remedy: Correct parameter settings. |
| Rotating Display Reset | Cause: RS input is ON or STOP/RESET key is pressed. Remedy: Release key or RS input. |
| —- Under-voltage (Indication) | Cause: If input voltage is under the allowed level, inverter shuts off output and waits with this indication. Remedy: Restore input voltage to allowed level. |
| 0000 Waiting to restart | Cause: This indication is displayed after tripping before restarting. Remedy: Wait for restart. |
| Blinking Communication error | Cause: Communication between inverter and digital operator fails. Remedy: Check connection between inverter and operator. |
How to Read WL200 Faults via ProDriveNext
While the on-board LED operator is useful for quick checks, connecting your PC to the WL200 using ProDriveNext software provides a higher level of diagnostic detail essential for 2026 maintenance standards.
- Trip History (d081 to d086): The WL200 stores the last 6 major trip events. You can access these via the Monitor (d) parameter group. Parameter d081 shows the most recent fault.
- Status Snapshot: When viewing a trip in d081, the display alternates between the error code and the inverter’s status—including output frequency, current, and DC bus voltage—recorded at the exact moment the trip occurred.
- Logic Debugging: If you are using the “Easy Sequence” internal logic, ProDriveNext allows you to monitor the PLC program execution to see if a custom logic error is triggering an E12 (External Trip).
General Troubleshooting Steps
Before performing a manual reset on your Hitachi WL200, perform these essential hardware checks:
- Overcurrent (E01 – E04): Check for short circuits in the motor wiring. If the trip happens only during acceleration, try increasing the Acceleration Time in parameter F002.
- Overvoltage (E07): Typically caused by a high-inertia load decelerating too quickly. Increase the Deceleration Time in parameter F003 or verify the status of the braking resistor if one is installed.
- Under-voltage (E09): Check for a sag in the input AC line voltage. This is often caused by an undersized power transformer or heavy loads starting elsewhere on the same circuit.
Frequently Asked Questions (FAQ)
Q: How do I reset a fault on the Hitachi WL200?
A: Once the cause of the trip is resolved, you can reset the drive using one of these methods:
- Press the Stop/Reset key on the front keypad.
- Activate the digital input terminal assigned to the RS (Reset) function (Terminal 5 is the default).
- Cycle the main input power (Wait for the display to go completely blank before turning the power back on).
Q: What does the “USP” code mean?
A: USP (Unattended Start Protection) is a safety feature, not a hardware fault. It prevents the motor from starting automatically if the “Run” command is already active when the drive is powered up. Simply turn the Run command OFF to clear the message.
Q: Why does my drive show “E14” (Ground Fault)?
A: E14 indicates that current is leaking to the earth on the output side. This is often caused by damaged motor insulation or moisture in the conduit. Warning: Repeatedly resetting a ground fault can cause catastrophic damage to the drive’s internal components.
Q: Where is the fault history located on the keypad?
A: You can find the history of the last 6 faults in the Monitor (d-group), specifically parameters d081 through d086. Each entry provides a log of the electrical data at the time of the error.