WEG CFW Fault Codes

F0021: Undervoltage on the DC Link

What it means: The DC link (DC bus) voltage dropped below the trip level and the drive stopped the motor. On the CFW500 the levels are 200 V DC for a 200 to 240 V supply, 360 V DC for 380 to 480 V and 500 V DC for 500 to 600 V.^[1][2][3]

Also on: CFW300 shows it as F021 Undervoltage on the DC Link; CFW11 shows it as F021 DC Bus Undervoltage. Trip levels differ by model and by the P296 or P0296 setting.

Likely causes

• Supply voltage too low or sagging
• A missing input phase
• Drive rating or parameter P0296 (line rated voltage) does not match the real supply
• Fault in the pre-charge circuit

First checks, in this order

1. Measure all input phases at the drive terminals and check the fuses and breaker.
2. Read the DC link voltage in P0004 while the drive runs.
3. Compare the drive nameplate and P0296 with the actual supply voltage.
4. If the supply is healthy and the trip repeats, suspect the pre-charge circuit and contact WEG service.

F0022: Overvoltage on the DC Link

What it means: The DC link voltage rose above the trip level: 410 V DC for a 200 to 240 V supply, 810 V DC for 380 to 480 V and 1000 V DC for 500 to 600 V on the CFW500. It usually happens while the motor decelerates a heavy load.^[1][2][3]

Also on: CFW300 shows it as F022 Overvoltage on the DC Link; CFW11 shows it as F022 DC Bus Overvoltage (trips above 400, 800, 1000 or 1200 V depending on P0296).

Likely causes

• High load inertia or a deceleration ramp that is too fast
• Supply voltage too high, or P0296 set wrong for the supply
• P0151, P0153 or P0185 set too high

First checks, in this order

1. Lengthen the deceleration time (P0101).
2. Measure the supply voltage and check that P0296 matches it.
3. Check the DC link regulation levels P0151 (V/f and VVW) and P0185 (vector), and the rheostatic braking level P0153.
4. On high inertia loads with a braking resistor fitted, check the resistor and its wiring.

F0070: Overcurrent/Short-circuit

What it means: The drive detected an overcurrent or short circuit at the output, in the DC link or at the braking resistor. This protection works in hardware and cuts the output pulses instantly.^[1][2][3]

Also on: CFW300 shows it as F070 Overcurrent/Short circuit; CFW11 as F070 Overcurrent / Short-circuit (frames A to C).

Likely causes

• Short circuit between two motor phases in the motor or cable
• Short circuit in the braking resistor cables
• Shorted or damaged IGBT module
• Acceleration ramp too short
• Starting into a motor that is still spinning without Flying Start

First checks, in this order

1. Power down, wait 10 minutes, disconnect the motor leads and check the motor and cable phase to phase.
2. Check the braking resistor cables, if fitted.
3. Increase the acceleration time (P0100).
4. If the motor can still be turning at start, enable Flying Start in P0320.
5. If the drive trips with the motor disconnected, the IGBT module is likely damaged: contact WEG service.

F0072: Motor Overload

What it means: The motor thermal model (Ixt) reached 100%: the motor carried more than its overload current for too long. For example, 150% of the overload current trips it in about 60 seconds. The level is shown in P0037.^[1][2][3]

Also on: CFW300 and CFW11 show it as F072 Motor Overload. On the CFW11, P0348 chooses fault, alarm, both or off.

Likely causes

• Overload currents P0156, P0157 and P0158 set too low for the motor
• Real overload on the motor shaft, such as a jam, tight bearing or process overload

First checks, in this order

1. Compare the motor current (P0003) with the motor nameplate.
2. Set P0156 about 10% above the motor rated current (P0401), as WEG recommends; P0157 and P0158 cover 50% and 20% of rated speed.
3. Check the machine for jams, worn bearings or extra load.
4. Watch P0037 to see how fast the overload level climbs.

A0046: Motor Overload

What it means: Early warning of motor overload: the overload level in P0037 has passed the alarm level in P0349 (85% by default). If the load stays high, fault F0072 follows at 100%.^[1][2][3]

Also on: CFW300 shows it as A046 Motor Overload; CFW11 shows it as A046 High Load on Motor (P0348 = 0 or 2 disables it).

Likely causes

• P0156, P0157 and P0158 set too low for the motor
• Overload on the motor shaft

First checks, in this order

1. Reduce the load or check the machine for mechanical problems.
2. Check the overload current settings P0156, P0157 and P0158 against the motor nameplate.
3. Check the alarm level in P0349 (100% switches this alarm off).

F0074: Ground Fault

What it means: Overcurrent from an output phase to ground (PE) was detected, usually a ground fault in the motor or motor cable.^[1][3]

Also on: CFW11 shows it as F074 Ground Fault (P0343 = 0 disables it); WEG notes that motor cables over 100 m can trip it.

Likely causes

• Short to ground in one or more output phases, motor or cable
• Motor cable capacitance too high (long cables), causing current peaks at the output

First checks, in this order

1. Power down, wait 10 minutes, disconnect the motor cable at the drive and insulation test the motor and cable to ground. Do not insulation test the drive itself.
2. Look for damaged cable, water in the terminal box or a burnt winding.
3. On long motor cables, expect leakage current to ground that can trip this right after the drive is enabled.
4. Bit 0 of P0343 can mask this fault, but WEG warns this can damage the drive: only under WEG guidance.

F0051: IGBTs Overtemperature

What it means: The power module (heatsink) temperature in P0030 passed the F0051 trip level, which is 90 to 123 °C depending on the model (P0029).^[1][2][3]

Also on: CFW300 shows it as F051 IGBTs Overtemperatures; CFW11 shows it as F051 IGBT Overtemperature U (F054 and F057 cover phases V and W on frames F to H).

Likely causes

• Ambient temperature around the drive above 50 °C with high output current
• Fan blocked or defective
• Heatsink clogged with dirt, blocking air flow

First checks, in this order

1. Measure the cabinet or room temperature near the drive.
2. Check that the heatsink fan runs; P0352 sets when it switches on.
3. Clean the heatsink and check the clearances around the drive.
4. Compare the output current (P0003) with the drive rating (P0295).
5. Let the drive cool before resetting.

A0050: Power Module Overtemperature

What it means: The power module temperature is 5 °C below the F0051 trip level. Near the limit the drive also lowers its switching frequency to 2000 Hz to protect itself.^[1][2][3]

Also on: CFW300 shows it as A050 IGBTs Overtemperatures; CFW11 shows it as A050 IGBT High Temperature U (P0353 can disable it).

Likely causes

• High ambient temperature with high output current
• Fan blocked or defective
• Dirty heatsink

First checks, in this order

1. Check cabinet ventilation and ambient temperature.
2. Check the fan and clean the heatsink.
3. Read the module temperature in P0030 and the load current in P0003.

F0048: Overload on the IGBTs

What it means: The drive's own power section is overloaded: output current above 1.5 times the heavy duty rating for too long (for example 3 s at 2 times the rated current in heavy duty).^[1][3]

Also on: CFW11 shows it as F048 IGBT Overload Fault.

Likely causes

• Output current above the drive rating (motor or load too big for the drive)
• Very short acceleration ramps or frequent heavy starts
• Normal duty (ND) selected in P0298 for a heavy duty load

First checks, in this order

1. Compare the output current (P0003) with the drive rated current (P0295).
2. Check the load and lengthen the acceleration time.
3. Check the duty setting in P0298; a larger drive may be needed.
4. Bit 1 of P0343 can mask this fault; WEG advises doing so only under its guidance.

A0047: IGBT Overload

What it means: Early warning that the power section overload level has passed the alarm level in P0349; fault F0048 follows if the current stays high.^[1][3]

Also on: CFW11 shows it as A047 IGBT Overload Alarm (P0350 can disable it).

Likely causes

• Inverter output overcurrent

First checks, in this order

1. Reduce the load or lengthen the acceleration time.
2. Compare the output current (P0003) with the drive rating (P0295).

F0006: Unbalance Line Phase Loss

What it means: Supply phase loss or supply unbalance. The delay is set in P0357; P0357 = 0 switches the protection off. With a light load on the motor it may not trip.^[1][3]

Also on: CFW11 shows it as F006 Imbalance or Input Phase Loss (input imbalance above 5%).

Likely causes

• A missing phase at the drive input (blown fuse, open breaker pole, loose terminal)
• Fault in the pre-charge circuit
• Single phase supply with P0357 not set to 0

First checks, in this order

1. Measure all three input phases at the drive terminals.
2. Check fuses, breaker and terminal tightness.
3. If the drive is fed single phase, set P0357 = 0 (frames A and B ship with 0).

F0076: Motor Connection Error

What it means: The drive sees a lost motor phase, unbalanced phase currents or a disconnected motor. It only checks while running above 10% of rated frequency and 20% of rated current.^[1][3]

Also on: CFW11 lists F076 as Motor Current Imbalance (P0342 = 0 disables it).

Likely causes

• Motor wiring or connection error
• Broken wire or loose connection between drive and motor
• An output contactor or disconnect between drive and motor opened

First checks, in this order

1. Check the U, V and W connections at the drive and in the motor terminal box.
2. Check any contactor or safety switch in the motor circuit.
3. Measure the three motor phase currents for balance.
4. Bit 4 of P0343 can mask this fault.

F0078: Motor Overtemperature

What it means: The motor triple PTC thermistor, read through an analog input (AIx) or digital input (DIx), shows overtemperature or a wiring problem. It trips above 3.9 kohm, and below 50 ohm when read on an analog input.^[1][2][3]

Also on: CFW300 shows it as F078 Motor Overtemperature (PTC on an analog input); CFW11 as F078 Motor Overtemperature (P0351 sets it; alarm A110 comes first).

Likely causes

• Motor overloaded or too many starts and stops per minute
• High ambient temperature around the motor or blocked motor cooling
• Poor contact or short circuit in the PTC wiring
• Thermistor not installed
• Motor shaft stuck

First checks, in this order

1. Feel or measure the motor temperature and check the motor fan and cooling fins.
2. Measure the PTC resistance at the drive terminals (normal is between 50 ohm and 3.9 kohm).
3. Check the input setup: P0231 or P0236 = 4 (PTC) for an analog input, or option 29 (PTC) in P0263 to P0270 for a digital input. DI2 cannot be used for PTC.
4. Check the duty cycle and load.

F0068: Motor Overtemperature (dedicated input)

What it means: Motor overtemperature measured by the motor triple PTC through the dedicated input circuit in the power section.^[1]

Likely causes

• Motor overloaded or high start and stop rate
• High ambient temperature around the motor
• Poor contact or short circuit in the PTC wiring
• Thermistor not installed or motor shaft stuck

First checks, in this order

1. Check the motor temperature, load and cooling.
2. Measure the PTC resistance and check the wiring to the dedicated input.
3. Check that the shaft turns freely.

F0033: Self-tuning Fault

What it means: At the end of VVW self-tuning, the measured stator resistance (P0409) does not fit the drive. Editing P0409 by hand can also cause it.^[1][2]

Also on: CFW300 shows it as F033 VVW Self-tuning Fault.

Likely causes

• Stator resistance in P0409 does not suit the drive power
• Motor connection error
• Motor much smaller or larger than the drive

First checks, in this order

1. Power down and check the motor terminal box: connection (star or delta) and all cable terminations.
2. Check that the motor nameplate data entered in the drive is correct.
3. Run self-tuning again (P0408) with the motor connected and stopped.

F0091: External Fault

What it means: A digital input set to No Ext. Fault (option 19 in P0263 to P0270) has opened, so an external device has stopped the drive. Output pulses are removed immediately.^[1][2][3]

Also on: CFW300 and CFW11 show it as F091 External Fault.

Likely causes

• The external device wired to that input opened, such as a thermal relay, interlock or emergency stop chain
• Open or loose wiring on DI1 to DI8

First checks, in this order

1. Find which input is set to 19 in P0263 to P0270.
2. Check the external device that feeds it and clear its cause.
3. Check the wiring and terminal for continuity.

A0090: External Alarm

What it means: A digital input set to No Ext. Alarm (option 18 in P0263 to P0270) is open. The drive keeps running and shows the alarm.^[1][2][3]

Also on: CFW300 and CFW11 show it as A090 External Alarm.

Likely causes

• External device signalling a warning
• Open or loose wiring on DI1 to DI8

First checks, in this order

1. Find which input is set to 18 in P0263 to P0270.
2. Check the external device and the wiring to that input.

F0080: CPU Fault (Watchdog)

What it means: The supervision of the main processor detected an internal error in firmware execution.^[1][2][3]

Also on: CFW300 shows it as F080 CPU Fault (Watchdog); CFW11 as F080 CPU Watchdog.

Likely causes

• Electrical noise
• Inverter firmware fault

First checks, in this order

1. Power cycle the drive and note whether it returns.
2. Check grounding and cable shields, and keep control wiring away from motor and power cables.
3. If it repeats, contact WEG.

F0084: Identification of the Power Hardware Failed

What it means: The drive could not identify its power section at start-up, for example after loading the factory default.^[1][2][3]

Also on: CFW300 and CFW11 show it as F084 Auto-diagnosis Fault.

Likely causes

• Poor contact between the main control and the power section
• Hardware not compatible with the firmware version
• Defect in the internal circuits

First checks, in this order

1. Power down and reseat the control unit and its connectors.
2. Check that the firmware version suits the hardware.
3. If it stays, contact WEG.

F0083: Hardware Identification Failed

What it means: The PWM setting stored in the drive does not match the power hardware it now detects, typically after the power section was replaced.^[1]

Likely causes

• Power hardware replaced by a model with a different PWM level
• Poor contact between the main control and the power section
• Defect in the internal circuits

First checks, in this order

1. After changing power hardware, load the factory default (P0204 = 5 or 6) and set the parameters again.
2. Reseat the connections between the control unit and the power section.

F0031: Communication Fault with Plug-in Module

What it means: The main control cannot talk to the plug-in (I/O or communication) module.^[1][2]

Also on: CFW300 shows it as F031 Fault in Communication with Expansion Accessory (see P027).

Likely causes

• Plug-in module damaged
• Plug-in module not seated properly
• Module identification problem (see P0027)

First checks, in this order

1. Power down and reseat the plug-in module.
2. Read P0027 to see which module the drive detects.
3. Try a known good module if available.

F0182: Pulse Feedback Fault

What it means: The circuit that feeds back the output voltage pulses has failed. It is used by dead time compensation and can be turned off in P0397.^[1][2][3]

Also on: CFW300 shows it as F182 Pulse Feedback Failure; CFW11 as F182 Pulse Feedback Fault, where WEG also lists no motor connected or a motor too small for the drive (P0356 = 0 is a suggested test).

Likely causes

• Hardware identification fault
• Fault in the internal pulse feedback circuit

First checks, in this order

1. Compare P0295 and P0296 with the drive identification label.
2. If they match and the fault stays, contact WEG.

F0079: Encoder Signal Fault

What it means: Encoder signals are missing.^[1][2][3]

Also on: CFW300 and CFW11 show it as F079 Encoder Signal Fault.

Likely causes

• Wiring between the encoder and the encoder interface accessory broken
• Defective encoder

First checks, in this order

1. Check the encoder cable, connectors and shield.
2. Check the encoder supply and the interface accessory.
3. Replace the encoder if the signals stay missing.

F0150: Motor Overspeed

What it means: Actual speed went above P0134 x (100% + P0132) for more than 20 ms.^[1][3]

Also on: CFW11 shows it as F150 Motor Overspeed.

Likely causes

• Speed regulator gains P0161 and P0162 set wrong
• Overhauling load such as a hoist

First checks, in this order

1. Check the maximum speed P0134 and overspeed margin P0132.
2. Tune the speed gains P0161 and P0162.
3. On hoists, check the braking arrangement and load behavior.

F0169: Speed Error too High

What it means: In vector control, the gap between speed reference and actual speed stayed above P0360 for longer than P0361. Alarm A0168 Speed Error too High warns first.^[1]

Likely causes

• Drive held in torque current limit for too long (load too heavy or ramp too fast)

First checks, in this order

1. Check the load and the acceleration time.
2. Check the torque current limit (P0169).
3. Check P0360 and P0361.

F0153: Internal Overtemperature

What it means: The air inside the drive (P0034) is above 85 °C.^[1][3]

Also on: CFW11 shows it as F153 Internal Air Overtemperature.

Likely causes

• Ambient temperature around the drive above 50 °C
• Heatsink clogged with dirt, blocking air flow

First checks, in this order

1. Check cabinet cooling, filters and fans.
2. Clean the heatsink.
3. Read P0034 after the drive cools to confirm the sensor reads sensibly.

A0152: High Internal Temperature

What it means: The air inside the drive (P0034) has reached 80 °C; fault F0153 follows at 85 °C.^[1][3]

Also on: CFW11 shows it as A152 Internal Air High Temperature (P0353 can disable it).

Likely causes

• High ambient temperature around the drive
• Dirty heatsink

First checks, in this order

1. Improve cabinet ventilation.
2. Clean the heatsink and check the fans.

F0179: Fan Low Speed

What it means: The internal fan speed (P0036) fell below 2/3 of its rated speed. WEG describes this for the IP66 models.^[1][3]

Also on: CFW11 shows it as F179 Heatsink Fan Speed Fault (P0354 = 0 disables it).

Likely causes

• Internal fan failure
• Fan not properly connected
• Fan clogged with dirt

First checks, in this order

1. Check the fan connector.
2. Clean the fan.
3. If it stays, contact WEG.

F0228: Telegram Reception Timeout

What it means: Serial communication fault: the drive received no valid telegram for longer than the time in P0314.^[1][2][3]

Also on: CFW300 shows it as F228 Timeout in Receipt of Telegrams; CFW11 as F228 Serial Communication Timeout.

Likely causes

• Broken cable, poor contact or poor grounding on the network
• Master polling slower than the timeout in P0314

First checks, in this order

1. Check the network cable, connectors, terminations and grounding.
2. Make sure the master sends telegrams faster than P0314.
3. P0314 = 0 turns the check off; P0313 sets what the drive does on a communication error.

A0128: Telegram Reception Timeout

What it means: Alarm version of the serial timeout: no valid telegram for longer than P0314.^[1][2][3]

Also on: CFW300 shows it as A128 Telegram Reception Timeout; CFW11 as A128 Timeout for Serial Communication.

Likely causes

• Network wiring or grounding problem
• Master polling too slowly

First checks, in this order

1. Check the network installation and the master.
2. Check P0314 (0 disables the check).

A0163: Signal Fault AIx 4..20 mA

What it means: An analog input set for 4 to 20 mA (or 20 to 4 mA) is reading below 2 mA, so the signal is likely lost.^[1][2][3]

Also on: CFW300 shows it as A163 Signal Fault AI1 4...20 mA (A164 for AI2); CFW11 as A163 Break Detect AI1 (A164 to A166 for AI2 to AI4).

Likely causes

• Broken or disconnected current signal wire
• Transmitter not powered
• Analog input set up wrong

First checks, in this order

1. Measure the loop current at the drive terminals.
2. Check the transmitter supply and wiring.
3. Check the analog input signal type setting and DIP switch.

F0700: Remote HMI Communication Fault

What it means: Communication with the remote keypad was lost while that keypad is a command or speed reference source (P0220 to P0228).^[1][2]

Also on: CFW300 uses code F701 for Remote HMI Communication Fault.

Likely causes

• Remote HMI cable disconnected
• Communication interface for the HMI set wrong in P0312

First checks, in this order

1. Check the remote keypad cable and connectors.
2. Check that P0312 is set for the remote HMI.

A0700: Remote HMI Communication Fault

What it means: Communication with the remote keypad was lost, but the keypad is not a command or reference source, so the drive keeps running.^[1][2]

Also on: CFW300 shows it as A700 Remote HMI Communication.

Likely causes

• Remote HMI cable disconnected
• P0312 set wrong

First checks, in this order

1. Check the keypad cable.
2. Check P0312.

F0160: Safety Functions Module in Fault State

What it means: The safety functions (STO) module has gone into its fault state.^[1]

Likely causes

• STO input signals wired incorrectly
• The two STO inputs disagree for more than 1 s
• Programming DIP switches (S2) left on in operation
• Safety function programming error or timeout (2 min)
• Damaged safety module

First checks, in this order

1. Check that both STO channels switch together.
2. Check that DIP switch S2 is in the operating position.
3. Check the safety function settings; replace the module if the fault stays.

A0160: Safe State Active

What it means: The safety functions module has put the drive in its safe state (safe torque off), so the motor cannot be driven.^[1]

Likely causes

• STO inputs actuated by the safety circuit
• STO input signals not installed
• STO input signals de-energized

First checks, in this order

1. Check the emergency stop or safety relay feeding the STO inputs.
2. Check the STO wiring and its supply.

F0086: Module Identification Failed

What it means: The drive could not identify the safety functions module.^[1]

Likely causes

• Poor contact between the drive and the safety functions module
• STO jumper connector missing when no safety module is used
• Internal defect in the drive or safety module

First checks, in this order

1. If no safety module is fitted, check that the STO jumper connector is in place.
2. Reseat the safety module.
3. If it stays, contact WEG.

F0087: Iu Current Offset Fault

What it means: The phase U current measurement shows a wrong offset. F0088 (Iv) and F0089 (Iw) are the same check for phases V and W.^[1]

Likely causes

• Electrical noise
• Internal cables disconnected
• Defect in the internal circuits

First checks, in this order

1. Power cycle the drive with the motor stopped.
2. Check grounding and cable shielding.
3. If it repeats, contact WEG service.

F0100: EEPROM Fault

What it means: The drive had problems loading parameters between its RAM and EEPROM memory at boot.^[1]

Likely causes

• Damaged control board
• Inverter firmware fault
• Defect in the internal circuits

First checks, in this order

1. Power cycle the drive.
2. If it repeats, contact WEG service; the control board may need replacing.

F0081: Firmware Update

What it means: A firmware update of the drive failed.^[1]

Also on: Same code, different meaning on other models: see the CFW300 and CFW11 F081 rows.

Likely causes

• Serial interface 1 not configured
• Serial settings not matching between WPS and the drive
• Lost telegrams or delays during the transfer
• Plug-in module firmware older than 1.03

First checks, in this order

1. Check that serial interface 1 is configured.
2. Set the WPS serial port and the drive to 38400 bps, 8 bits, even parity, 2 stop bits.
3. Check the cable and connection, then repeat the update.

A0181: Invalid Clock Value

What it means: The real time clock has no valid date and time.^[1][3]

Also on: CFW11 shows it as A181 Invalid Clock Value.

Likely causes

• Date and time not set
• Keypad battery flat, defective or missing

First checks, in this order

1. Set the date and time in P0194 to P0199.
2. Replace the keypad battery (type CR2032) if it does not hold the time.

A0211: Drive in Fire Mode

What it means: Fire Mode is active: the digital input that activates Fire Mode is on.^[1][2]

Also on: CFW300 shows it as A211 Drive in Fire Mode. On the CFW11, A211 has a different meaning (see the CFW11 A211 row).

Likely causes

• Fire Mode input activated by the building or process system

First checks, in this order

1. Confirm whether Fire Mode was meant to be active.
2. Check the digital input set for Fire Mode and its wiring.

F0234: Bus Off

What it means: The CAN interface (CANopen or DeviceNet) went bus off because of too many communication errors.^[1][2][3]

Also on: CFW300 and CFW11 show it as F234 Bus Off.

Likely causes

• Short circuit on the CAN cable
• Cables swapped or misconnected
• Devices on the network using different baud rates
• Termination resistors wrong or not only at the ends of the bus

First checks, in this order

1. Check the CAN cable for shorts and swapped wires.
2. Check that all devices use the same baud rate.
3. Check that termination resistors are fitted only at the two ends of the main bus.
4. Check P0703 (bus off reset: manual or automatic).

F0249: Ethernet Off-line

What it means: Cyclic Ethernet communication stopped. For PROFINET IO or EtherNet/IP the link to the master was lost; for Modbus TCP no valid telegram arrived within the time set in P0806.^[1][2]

Also on: CFW300 shows F249 as Timeout Modbus TCP (timeout set in P868).

Likely causes

• Broken cable or poor contact on the network
• Master not configured or not running
• Modbus TCP client polling slower than P0806

First checks, in this order

1. Check the Ethernet cable, switch port and grounding.
2. Check the master or client configuration and status.
3. For Modbus TCP, poll faster than P0806 or change the timeout.

A0764: Frequency Inverter in Sleep Mode

What it means: Not a fault: the internal PID controller has put the drive to sleep because speed stayed below P1028 for the time in P1029. It wakes when the process demands it.^[1]

Likely causes

• Low process demand while the PID controller is in automatic mode

First checks, in this order

1. Confirm the process really has low demand.
2. Check the sleep speed P1028 and sleep time P1029 if the drive sleeps too often.

F0767: Dry Pump Detected

What it means: The pump runs above the speed in P1034 but motor torque stayed below P1035 for the time in P1036, which suggests the pump is running dry. It is a fault when P1033 = 2 (A0766 is the alarm version with P1033 = 1).^[1]

Likely causes

• Low or no liquid at the pump suction
• Closed suction valve or air in the pump
• Dry pump thresholds set too high for the application

First checks, in this order

1. Check the suction level, valves and priming.
2. Check P1034, P1035 and P1036 against normal running torque.

F0769: Broken Belt Detected

What it means: The motor runs above the speed in P1038 but torque stayed below P1039 for the time in P1040, which suggests a broken or slipping belt. It is a fault when P1037 = 2 (A0768 is the alarm version).^[1]

Likely causes

• Broken, loose or slipping drive belt
• Coupling failure
• Broken belt thresholds set too high

First checks, in this order

1. Inspect the belt and pulleys.
2. Check P1038, P1039 and P1040 against normal running torque.

F067: Incorrect Encoder/Motor Wiring

What it means: The phase relation of the encoder signals does not match the motor, so the encoder and motor wiring disagree.^[2][3]

Also on: CFW300 lists F067 with the same name; its auto-reset (P340) does not apply to F067.

Likely causes

• Motor output cables U, V and W swapped
• Encoder channels A and B swapped
• Encoder not mounted properly
• Motor rotor locked or dragged at start (CFW11)

First checks, in this order

1. Check the U, V and W order at the drive and motor.
2. Check the encoder A and B channel wiring.
3. Check the encoder mounting and coupling.
4. On the CFW11 this fault cannot always be reset: power off, fix the cause, then power on. P0358 can disable it.

A177: Fan Replacement

What it means: The heatsink fan has run more than 50000 hours (counter P0045) and is due for replacement.^[2][3]

Also on: CFW300 shows it as A177 Replace Fan (P045 above 50000 hours).

Likely causes

• Fan operating hours have reached the replacement limit

First checks, in this order

1. Replace the heatsink fan.
2. On the CFW11, reset the fan hour counter with P0204 = 2; P0354 = 0 disables this alarm.

F081: End of User's Memory

What it means: On the CFW300, the user parameter table is full: you tried to save more than 32 parameters that differ from factory default.^[2]

Also on: Different meaning on the CFW500 (F0081 Firmware Update) and CFW11 (F081 Corrupted Language Fault).

Likely causes

• Saving to the user table (P204 = 9) with more than 32 changed parameters

First checks, in this order

1. Reduce the number of parameters changed from factory default before saving to the user table.

F081: Corrupted Language Fault

What it means: On the CFW11, changing the keypad language failed; afterwards the language falls back to English.^[3]

Also on: Different meaning on the CFW500 (F0081 Firmware Update) and CFW300 (F081 End of User's Memory).

Likely causes

• Electrical noise or a supply interruption during the language change

First checks, in this order

1. Set the language again with the drive powered steadily.
2. Check grounding and noise sources if it repeats.

F071: Output Overcurrent

What it means: On the CFW11, output current stayed too high for too long.^[3]

Likely causes

• High load inertia or acceleration time too short
• P0135 or P0169 to P0172 set too high

First checks, in this order

1. Lengthen the acceleration time.
2. Check the current limit P0135 and the torque current limits P0169 to P0172.
3. Check the mechanical load.

F030: Power Module U Fault

What it means: On CFW11 frames D to H, an IGBT in the phase U power module desaturated (very high current). F034 and F038 are the same fault for phases V and W.^[3]

Likely causes

• Short circuit between motor phases U and V or U and W

First checks, in this order

1. Power down, wait 10 minutes, disconnect the motor and check the motor and cable phase to phase.
2. If the cable and motor test good and the fault stays, contact WEG service.

F077: DB Resistor Overload

What it means: On the CFW11, the dynamic braking resistor overload protection tripped.^[3]

Likely causes

• High load inertia or deceleration time too short
• Excessive load on the motor shaft
• Resistor settings P0154 and P0155 wrong

First checks, in this order

1. Lengthen the deceleration time.
2. Check that P0154 and P0155 match the installed braking resistor.
3. Check the resistor rating against the braking duty.

F185: Pre-charge Contac Fault

What it means: On CFW11 frames E and H, the pre-charge contactor did not work as expected.^[3]

Likely causes

• Defective pre-charge contactor (frame E)
• Open control fuse
• Phase loss at input L1/R or L2/S (frame E)
• Frame E drive fed from a DC link without P0355 = 0

First checks, in this order

1. Check the input phases and the control fuse.
2. If the drive is fed from a DC bus, set P0355 = 0 as WEG instructs.
3. If it stays, contact WEG service about the pre-charge contactor.

A110: High Motor Temperature

What it means: On the CFW11, the motor PTC reads above about 3.51 kohm, an early warning before fault F078 at 3.9 kohm.^[3]

Likely causes

• Motor load too high or too many starts and stops
• High ambient temperature around the motor
• Loose connection or short circuit in the thermistor wiring
• Thermistor not installed or motor shaft blocked

First checks, in this order

1. Check the motor load, cooling and duty cycle.
2. Check the PTC wiring and the analog input and output set to PTC.
3. Check P0351, which sets the alarm and fault behavior.

A211: Fire Mode Test Mode

What it means: On the CFW11, the test mode of the Fire Mode function is on (Fire Mode enabled and P0000 = 193).^[3]

Also on: On the CFW500 (A0211) and CFW300 (A211) this code means Drive in Fire Mode.

Likely causes

• Fire Mode test left enabled after commissioning

First checks, in this order

1. Finish the Fire Mode test and take the drive out of test mode.

E00: Output overcurrent/short-circuit/output ground fault

What it means: CFW08: overcurrent at the output, between phases or from a phase to ground.^[4][5]

Also on: CFW10 lists E00 Output Overcurrent/Short-Circuit (between phases).

Likely causes

• Short circuit between two motor phases, or from a phase to ground
• Motor cable capacitance to ground too high (cables longer than 50 m)
• Load inertia too high or acceleration ramp too short
• P169 set too high, or P136 and P137 set wrong in V/F control
• Shorted IGBT module

First checks, in this order

1. Power down, wait 10 minutes and check the motor and cable phase to phase and to ground.
2. Lengthen the acceleration ramp and check P169, P136 and P137.
3. On long motor cables, reduce the switching frequency (P297) or fit a load reactor.
4. Reset by power cycle, the keypad reset key, auto-reset (P206) or a digital input.

E01: DC link overvoltage

What it means: CFW08: the DC link voltage went above 410 V on 200 to 240 V models or 820 V on 380 to 480 V models.^[4][5]

Also on: CFW10 lists E01 DC Link Overvoltage (also 460 V on 110 to 127 V models).

Likely causes

• Supply voltage too high
• Load inertia too high or deceleration ramp too short
• P151 set too high

First checks, in this order

1. Measure the supply voltage.
2. Lengthen the deceleration ramp.
3. Check P151.

E02: DC link undervoltage

What it means: CFW08: the DC link voltage fell below 200 V on 200 to 240 V models or 360 V on 380 to 480 V models (read it in P004).^[4][5]

Also on: CFW10 lists E02 DC Link Undervoltage (also 250 V on 110 to 127 V models).

Likely causes

• Supply voltage too low
• Missing input phase or blown fuse

First checks, in this order

1. Measure the supply voltage at the drive terminals.
2. Check fuses and connections.
3. Read the DC link voltage in P004.

E04: Overtemperature at the power heatsink or in the inverter internal air

What it means: CFW08: the heatsink or the air inside the drive is too hot.^[4][5]

Also on: CFW10 lists E04 Inverter Overtemperature (heatsink trip at 103 °C, 133 °C on the 15.2 A model).

Likely causes

• Ambient temperature above 40 °C and/or output current too high
• Blower locked or defective
• Internal air too hot on some models with built-in RFI filters

First checks, in this order

1. Let the drive cool down before resetting.
2. Check the blower and air flow, including the internal blower on filtered models.
3. Check ambient temperature and load current.

E05: Output overload (Ixt function)

What it means: CFW08: the motor or drive overload function (Ixt) tripped.^[4][5]

Also on: CFW10 lists E05 Output Overload (Ixt function).

Likely causes

• P156 set too low for the motor
• Too much load on the motor shaft

First checks, in this order

1. Check P156 against the motor rated current.
2. Check the mechanical load.

E06: External fault

What it means: CFW08: a digital input programmed for external fault is open (not connected to GND on XC1).^[4][5]

Also on: CFW10 lists E06 External Fault (DI1 to DI4).

Likely causes

• External interlock opened
• Open wiring on the external fault input

First checks, in this order

1. Find the digital input programmed for external fault.
2. Check the external device and the wiring to GND (XC1).

E08: CPU error (Watchdog)

What it means: CFW08: the processor watchdog tripped.^[4][5]

Also on: CFW10 lists E08 CPU Error (watchdog).

Likely causes

• Electrical noise

First checks, in this order

1. Check grounding and shielding, and separate control wiring from power wiring.
2. Power cycle the drive; contact WEG if it repeats.

E24: Programming error

What it means: CFW08: incompatible parameters were programmed. It clears by itself once the conflicting parameters are changed.^[4][5]

Also on: CFW10 lists E24 Programming Error.

Likely causes

• Two parameter settings that conflict (see table 4.1 of the manual)

First checks, in this order

1. Review the last parameters you changed and correct the conflict, for example digital input start and stop functions that must be set as a pair.

E32: Motor overtemperature (external PTC)

What it means: CFW08: the motor PTC thermistor reports overtemperature or a wiring fault.^[4]

Likely causes

• Motor overloaded or duty cycle too high
• Ambient temperature too high
• Bad contact or short circuit (below 100 ohm) in the PTC wiring at XC1

First checks, in this order

1. Check motor load and cooling.
2. Check the PTC wiring at the control terminals (XC1:6 and 7 or XC1:7 and 8).

E41: Self-diagnosis fault

What it means: CFW08: the self test found a defect in the power circuit, and the drive cannot be enabled.^[4][5]

Also on: CFW10 lists E41 Self-Diagnosis Error.

Likely causes

• Defective inverter power circuit

First checks, in this order

1. Contact WEG service.