Having trouble with your WEG CFW10 micro VFD? Learn how to identify, troubleshoot, and reset EXX error codes to keep your operations running smoothly.

The WEG CFW10 is a compact, legacy micro variable frequency drive (VFD) designed for scalar (V/F) control of three-phase induction motors . Ranging from 0.18 kW to 4 kW (0.25 to 5 HP), this drive is widely used in simple automation systems such as fans, pumps, mixers, and small conveyors . To protect the motor, cabling, and internal circuits, the CFW10 is equipped with protective trip sensors .

When the drive detects a system abnormality, it disables the motor output and displays a flashing fault code on its integrated 3-digit LED screen in the format of EXX (where XX represents the error number) . Knowing how to read, diagnose, and reset these codes is crucial to maintaining uptime and protecting your equipment.

WEG CFW10 Fault Codes Reference Table

Locate the active fault code flashing on your drive’s HMI display to match the error to its specific operational cause.

WEG CFW10 Drive Fault Codes List

Fault / Alarm and Meaning	Cause and Remedy
E00 Output Overcurrent (between phases)	Cause: Short-circuit between two motor phases. Short circuit between ground and one or more output phases (if occurring during power-up). Inertia of the load is too high, or acceleration ramp is too short. Parameter P169 configured too high. Incorrect configuration/setting of parameters P136 and/or P137. IGBT transistor module is short-circuited. Remedy: Check output motor cabling for phase-to-phase short-circuits. Check for ground short-circuits on output phases. Increase the acceleration ramp time or reduce load inertia. Verify control parameters, and decrease parameter P169 or parameters P136/P137 if configured incorrectly. Inspect output IGBT modules. Reset options: Power-on, Manual reset (Key 0), Auto-Reset, DI (Digital Input).
E01 DC Link Overvoltage	Cause: Power supply voltage is too high, generating in the DC link a voltage higher than the allowed value: Models 200-240 V: Ud > 410 V Models 110-127 V: Ud > 460 V Additional factors: Load inertia too high and deceleration ramp is too short. Setting of parameter P151 is configured too high. Remedy: Verify incoming mains supply voltage stability. Increase deceleration ramp time or reduce load inertia. Use a dynamic braking resistor if required. Decrease parameter P151 if configured too high. Reset options: Power-on, Manual reset (Key 0), Auto-Reset, DI (Digital Input).
E02 DC Link Undervoltage (Ud)	Cause: Power supply voltage is too low, causing a DC link voltage below the allowed value (monitored in parameter P004): Models 200-240 V: Ud < 200 V Models 110-127 V: Ud < 250 V Remedy: Check incoming supply voltage (P004) and ensure compliance with drive ratings. Check for input phase losses or general voltage drops. Reset options: Power-on, Manual reset (Key 0), Auto-Reset, DI (Digital Input).
E04 Inverter Overtemperature	Cause: Ambient temperature too high (> 50 ºC), (> 40 °C for the 15.2 A model) and/or output current too high. Blocked or defective fan. Note: The heatsink overtemperature protection (E04) is activated when the heatsink temperature (P008) reaches 103 ºC (or 133 ºC for the 15.2 A model). Remedy: Allow the inverter to cool down before attempting to reset. Clean heatsink fins and verify that the cooling fan is operating correctly. Ensure surrounding ambient temperature is within limits. Reset options: Power-on, Manual reset (Key 0), Auto-reset, DI (Digital Input).
E05 Overload at output (I × t Function)	Cause: Parameter P156 is configured too low for the connected motor. Motor is under an actual overload condition. Remedy: Verify motor current settings (P156) match motor nameplate rating. Reduce motor shaft load. Reset options: Power-on, Manual reset (Key 0), Auto-reset, DI (Digital Input).
E06 External Error	Cause: Wiring at digital inputs DI1 through DI4 is open [not connected to GND (pin 5 of the XC1 control connector)]. Note: Valid when digital input programmed for external fault is open. Remedy: Verify external fault wiring connections on digital inputs. Ensure inputs DI1 through DI4 are connected to GND (pin 5 of the XC1 connector) under normal conditions to prevent false triggering. Reset options: Power-on, Manual reset (Key 0), Auto-reset, DI (Digital Input).
E08 CPU Error	Cause: High electrical noise. Remedy: Check the cabinet grounding and shield terminations to mitigate noise. Reset options: Power-on, Manual reset (Key 0), Auto-reset, DI (Digital Input).
E09 Program Memory Error (Checksum)	Cause: Memory with corrupted values. Remedy: This indicates internal card memory failure. Please contact WEG technical support for control board evaluation. Reset: Contact WEG (refer to section 7.3).
E24 Programming error	Cause: Incompatible parameters were programmed. Refer to table 5.1. Remedy: This fault is automatically reset when the incompatible parameters are correctly programmed. Resolve conflicting parameter values according to manual Table 5.1 definitions.
E31 Keypad (HMI) Connection Fault	Cause: Inverter control circuit is defective. Electrical noise in the installation (electromagnetic interference). Remedy: Check keypad RJ45/serial cable connections. Protect the cable from electromagnetic noise. If the inverter control circuit itself is defective, contact WEG Servicing (Refer to section 7.3). Reset: Contact WEG Servicing (Refer to section 7.3).
E41 Self-Diagnosis Fault	Cause: Inverter power circuit is defective. Remedy: Contact WEG technical support/servicing for hardware evaluation. Reset: Contact WEG Servicing (refer to section 7.3).

How to Access the Last Fault Parameter

If the fault has been cleared but you need to view the history of the trip for diagnostic purposes, you can retrieve the code of the most recent event by checking Parameter P015 (Last Fault) . This parameter displays the numeric value of the last active fault (e.g., 01 for E01) .

How to Safely Reset a WEG CFW10 Fault

Once you have identified the fault and resolved the root cause, you must clear the trip condition to restart the drive. The CFW10 can be reset using one of four methods :

1. Power Cycle (Power-On Reset): Turn off the main AC power supply . Safety Requirement: Wait at least 10 minutes to allow the internal DC-link capacitors to discharge to a safe voltage level before handling wiring or re-energizing the drive.
2. HMI Keypad Reset: Press the red O/RESET key on the front control panel .
3. Digital Input (DI) Reset: If one of your digital inputs (DI1 through DI4) is assigned to the "Reset" function via parameters P263 to P266, you can apply a momentary pulse to that terminal .
4. Auto-Reset Parameter: Parameter P206 allows the drive to automatically reset after a specified delay time . Note that configuring this parameter is best suited for self-clearing transient power anomalies.

Most Common CFW10 Faults and Quick Diagnostics

While the full diagnostics list includes multiple codes, a few main errors represent the majority of field trips on these micro drives:

1. E00 (Output Overcurrent / Short-Circuit)

E00 indicates that the drive has detected a sudden surge in current exceeding its safe limit . This can occur due to a phase-to-phase short circuit in the motor wiring, a ground fault, a mechanical motor jam, or internal damage to the drive's output power module (IGBT) .

• Diagnostic: Disconnect the motor leads from terminals U, V, and W. Perform an insulation test (megger test) on the motor cabling. If the E00 fault persists even after the motor cables are disconnected, the drive’s internal power module may be compromised.

2. E01 (DC Link Overvoltage)

E01 is triggered when the voltage on the drive’s internal DC bus rises too high . This is common during motor deceleration when the load regenerates kinetic energy back into the drive .

• Diagnostic: Try increasing the deceleration ramp time (P101) to decelerate the load more slowly. If your application has a high-inertia load that must stop quickly, ensure your model has dynamic braking capability and verify the braking resistor connections .

3. E24 (Programming / Self-Diagnosis Error)

E24 occurs when parameters are configured in an incompatible layout . A very common example of this occurs when configuring 3-wire control:

• Diagnostic: If you set Digital Input 1 to "Start" (P263 = 13), an E24 error will immediately trigger and remain active until Digital Input 2 is correctly configured to "Stop" (P264 = 14) . Verify that both interdependent parameters are mapped correctly.

4. E04 (Overtemperature at Power Assembly)

This code indicates that the drive's heatsink has exceeded its thermal limit . This is often caused by a restricted airflow path or high ambient temperatures inside the control panel .

• Diagnostic: Inspect the heatsink fins for dust or debris accumulation. Ensure the drive's mounting distance from adjacent equipment follows the spacing recommendations in the manual to allow proper heat dissipation.

Best Practices to Avoid CFW10 Drive Trips

To reduce unexpected downtime and prolong the lifespan of your micro VFD, keep these maintenance tips in mind:

• Clean Dust Regularly: Because the CFW10 series is compact, dust accumulation on the heatsink or internal boards can quickly restrict airflow . Periodically blow out the drive with clean, dry air.
• Check Terminal Screw Torque: Vibration and thermal shifts can cause power connections to loosen over time. Periodically check and retorque the input, output, and control terminal connections.
• Verify Ambient Limits: Ensure that the control enclosure is well-ventilated, especially if the drive runs at high switching frequencies or near its full current capacity.

By understanding what the CFW10 is communicating and following a proactive maintenance routine, you can ensure reliable operation and minimize process interruptions.