dEv (Speed Deviation for Control Mode with PG):

    Cause: The deviation between the speed reference and speed feedback is greater than the setting in F1-10 for longer than the time set to F1-11.
    Possible Solution: Reduce the load, increase the acceleration and deceleration times, check the machine, check the settings of parameters F1-10 and F1-11, adjust the speed feedback scaling, and ensure the motor brake releases properly.

dv1 (Z Pulse Fault):

    Cause: The motor turned one full rotation without the Z Pulse being detected.
    Possible Solution: Ensure the PG encoder is properly connected and grounded, cycle power, and if the problem continues, replace the PG option card or the PG encoder.

dv2 (Z Pulse Noise Fault Detection):

    Cause: The Z Pulse is out of phase by more than 5 degrees for the number of times specified in parameter F1-17.
    Possible Solution: Separate the PG cable lines from the source of the noise, rewire the PG encoder properly, and ground all shielded lines. If the problem continues after cycling power, replace the PG option card or the PG encoder.

dv3 (Inversion Detection):

    Cause: The torque reference and acceleration are in opposite directions, and the speed reference and actual motor speed differ by more than 30% for the number of times set to F1-18.
    Possible Solution: Set the Z Pulse offset to E5-11 as specified on the motor nameplate, rewire the PG encoder properly, and ensure the motor is rotating in the correct direction. Fix any problems on the load side causing the motor to rotate in the opposite direction.

dv4 (Inversion Prevention Detection):

    Cause: Pulses indicate that the motor is rotating in the opposite direction of the speed reference.
    Possible Solution: Set the Z Pulse offset to E5-11 as specified on the motor nameplate, rewire the PG encoder properly, and ensure the motor is rotating in the correct direction. If the problem continues, replace the PG option card or the PG encoder.

dv7 (Polarity Judge Timeout):

    Cause: Disconnection in the motor coil winding or loose output terminals.
    Possible Solution: Measure the motor line-to-line resistance and replace the motor if necessary. Check for loose terminals and apply the specified tightening torque to fasten them.

dWAL, dWFL (DriveWorksEZ Fault):

    Cause: Fault output by DriveWorksEZ.
    Possible Solution: Correct the cause of the fault. This may involve checking the DriveWorksEZ settings and ensuring they are configured correctly for the application.

E5 (SI-T3 Watchdog Timer Error):

    Cause: The watchdog timed out.
    Possible Solution: Execute DISCONNECT or ALM_CLR, then issue a CONNECT command or SYNC_SET command and proceed to phase 3. Refer to the SI-T3 Option Technical Manual for more details on troubleshooting.

EF0 (Option Card External Fault):

    Cause: An external fault condition is present.
    Possible Solution: Remove the cause of the external fault, remove the external fault input from the PLC, and check the PLC program for problems.

EF1 to EF8 (External Fault at Multi-Function Input Terminals S1 to S8):

    Cause: An external device tripped an alarm function or there is incorrect wiring.
    Possible Solution: Remove the cause of the external fault and reset the fault. Properly connect the signal lines to the terminals assigned for external fault detection (H1-oo = 20 to 2F). Check for unused terminals set for external fault detection and change the terminal settings if necessary.

Err (EEPROM Write Error):

    Cause: Data cannot be written to the EEPROM.
    Possible Solution: Press "ENTER" on the digital operator, correct the parameter setting, cycle power to the drive, and if the problem continues, replace the control board or the entire drive. Contact Yaskawa or a representative for instructions on replacing the control board.

FAn (Internal Fan Fault):

    Cause: Fan or magnetic contactor failure.
    Possible Solution: Cycle power to the drive, check for fan operation, verify the cumulative operation time of the fan with monitor U4-03 and the fan maintenance timer with U4-04. If the cooling fan has exceeded its expected performance life or is damaged, follow the replacement instructions in the Peripheral Devices & Options chapter. If there is a fault detected in the internal cooling fan or magnetic contactor to the power supply, replace the power board/gate drive board or the entire drive.

FbH (Excessive PID Feedback):

    Cause: PID feedback input is greater than the level set to b5-36 for longer than the time set to b5-37.
    Possible Solution: Check b5-36 and b5-37 settings, correct the PID feedback wiring, and check or replace the feedback sensor if damaged.

FbL (PID Feedback Loss):

    Cause: PID feedback level is below the detection level set to b5-13 for longer than the time set to b5-14.
    Possible Solution: Check b5-13 and b5-14 settings, correct the PID feedback wiring, and check or replace the feedback sensor if damaged.

GF (Ground Fault):

    Cause: A current short to ground exceeded 50% of rated current on the output side of the drive, or there is excessive leakage current at the drive output.
    Possible Solution: Check the insulation resistance of the motor, check and replace the motor cable if needed, reduce the carrier frequency, reduce the amount of stray capacitance, enable Speed Search at Start (b3-01 = 1), and perform Speed Search 1 or 2 (H1-oo = 61 or 62) via one of the external terminals. If the problem continues, replace the control board or the entire drive.