5.4 Fault Detectionu Fault Displays, Causes, and Possible SolutionsFaults are detected for drive protection, and cause the drive to stop while triggering the fault output terminal MA-MB-MC.Remove the cause of the fault and manually clear the fault before attempting to run the drive again.Table 5.10 Detailed Fault Displays, Causes, and Possible SolutionsHOA Keypad Display Fault NamebAT HOA Keypad Battery Voltage LowCause Possible SolutionThe HOA keypad battery is low Replace the HOA keypad battery.HOA Keypad Display Fault NamebUSOption Communication Error• The connection was lost after establishing initial communication.• Only detected when the run command frequency reference is assigned to an option card.Cause Possible SolutionNo signal was received from the PLC • Check for faulty wiring.• Correct the wiring.• Check for disconnected cables and short circuits and repair as needed.Faulty communications wiring or an existing shortcircuitCommunication data error occurred due to noise• Check the various options available to minimize the effects of noise.• Counteract noise in the control circuit, main circuit, and ground wiring.• Ensure that other equipment such as switches or relays do not cause noise. Use surge absorbers ifnecessary.• Use only recommended cables or other shielded line. Ground the shield on the controller side orthe drive input power side.• Separate all communication wiring from drive power lines.The option card is damaged Replace the option card if there are no problems with the wiring and the error continues to occur.The option card is not properly connected to thedrive• The connector pins on the option card do not line up properly with the connector pins on the drive.• Reinstall the option card.HOA Keypad Display Fault NameCE MEMOBUS/Modbus Communication ErrorControl data was not received for the CE detection time set to H5-09.Cause Possible SolutionFaulty communications wiring or an existing shortcircuit• Check for faulty wiring.• Correct the wiring.• Check for disconnected cables and short circuits and repair as needed.Communication data error occurred due to noise• Check the various options available to minimize the effects of noise.• Counteract noise in the control circuit, main circuit, and ground wiring.• Use only recommended cables or other shielded line. Ground the shield on the controller side orthe drive input power side.• Ensure that other equipment such as switches or relays do not cause noise. Use surge suppressorsif required.• Separate all communication wiring from drive power lines.HOA Keypad Display Fault NameCoF Current Offset FaultCause Possible SolutionThe drive tried to adjust the current offset valuebeyond the allowable range. This is due to residualinduction current in the motor (e.g., during suddendeceleration or when coasting) when the driveattempted to start the motor.• Create a motor restart sequence that allows enough time for residual induction voltage to dissipate.• Enable Speed Search at start (b3-01 = 1). Use the multi-function terminals to execute ExternalSpeed Search 1 and 2 (H1-oo = 61 or 62).Note: When using a PM motor, External Speed Searches 1 and 2 perform the same operation.The current sensor in the drive is damaged If the problem continues, replace the control board or the entire drive. Contact Yaskawa or a Yaskawarepresentative for instructions on replacing the control board.5.4 Fault DetectionYASKAWA ELECTRIC TOEP C710616 45F YASKAWA AC Drive – Z1000 User Manual 2075 Troubleshooting
