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EP400 Error Codes List: E000 to E911 Troubleshooting Guide

During the operation of the OTC DAIHEN EP400 welding machine, if a fault occurs, the display panel will pop up the corresponding abnormal alarm code. To assist maintenance technicians in quickly locating the problem, we have compiled a comprehensive troubleshooting guide covering common error codes from E000 to E911, along with official solutions.

OTC EP400 Abnormal Alarm Code Quick Reference Table

Alarm CodeAbnormality DescriptionSolution / Countermeasure
E000Terminals [STOP] DisconnectedConfirm if the external terminal block TM5 [STOP] (34) is open-circuited. To clear the abnormality, set function [F4].
E010Torch Switch OFF WaitConfirm if the torch trigger/switch is stuck in the ON position upon startup.
E020Inching Feed OFF WaitConfirm if the wire inching switch is stuck in the ON position.
E030-E037USB Communication ErrorCheck the USB drive connection, re-insert it, and restart the power.
E040-E042Startup Communication ErrorThis will disappear upon restarting the power supply.
E050-E059Control Board Communication ErrorThis will disappear upon restarting the power supply.
E100Control Power Supply ErrorCheck the +24V and ±15V power supplies. Restart the power.
E150Input OvervoltageConfirm if the input voltage is within the 342-418V range. Restart the power.
E160Input UndervoltageConfirm the input voltage is 342-418V. Check function [F20] settings.
E200Primary Current Detector ErrorCheck the contact status of the P30099P_CN25 connector.
E210Arc Voltage Detection ErrorCheck the welding cable and detection wire for open circuits or short circuits.
E220Primary Main Circuit ErrorConfirm if the internal IGBT module is damaged.
E230Primary Drive ErrorCheck P30099P_CN21-CN24 connectors and test the waveforms.
E240Secondary Current Detector ErrorCheck the P30099P_CN29 connector on the circuit board.
E260Voltage Detection Loop ErrorCheck the P30099P_CN27 connector on the circuit board.
E301Primary IGBT Side Temp ErrorConfirm P30099P_CN11 connector. Check the duty cycle and ambient temperature.
E302Secondary DR Side Temp ErrorConfirm P30099P_CN12 connector. Check the duty cycle and ambient temperature.
E615Memory Backup WarningPress any key to clear. Check if saved welding conditions have been initialized.
E700Output Overcurrent ErrorCheck if the contact tip is touching the base metal, or if the welding cable is short-circuited.
E710W-Phase Loss ErrorCheck the primary input cables and distribution wiring.
E800-E801Wire Feeder Encoder ErrorCheck the wire feeder control connections and motor status.
E810Wire Feed Motor Drive Temp ErrorCheck the torch and wire feeder for jammed welding wire.
E850Wire Feeder Control Power ErrorCheck P30087Q_CH2-CH1 24V power supply.
E860Wire Feed Motor Power ErrorCheck P30087Q_CH10-CH9 48V power supply.
E900-E907Software ErrorIf restarting fails to clear the error, please contact an authorized agent.
E910-E911OS ErrorIf restarting fails to clear the error, please contact an authorized agent.

Global After-Sales Service & Technical Support

If you encounter unresolved alarm codes during troubleshooting or need original OTC DAIHEN spare parts, please feel free to contact our expert team. We guarantee 100% genuine original components.

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