The OTC DAIHEN DM350 / DM500 welding machines are highly acclaimed in the steel structure and machining sectors for their stable arc ignition and precise wire feeding control. When the equipment encounters power grid fluctuations, overload overheating, or excessive wire feeding resistance under harsh working conditions, the digital display on the front panel will flash an “E-XXX” error code and automatically cut off the output. Notably, the DM series features a dedicated set of “E800-class” alarm codes exclusively for wire feeding system detection. This article summarizes the cause analysis and official troubleshooting reset methods for the common error codes across the entire DM350/500 welder series, helping you quickly restore production.
1. After-Sales Expert Warning: Understand the Code Before Acting; Never Restart Blindly!
Before troubleshooting against the list below, equipment maintenance personnel must pay attention to the following two points:
- Strictly Prohibit Shutting Down During an E300 Alarm: When an E300 (Over-Temperature Error) occurs, it indicates that the internal heatsink has overheated. Do not turn off the main power immediately! You must keep the power on to allow the internal cooling fan to continue running for at least 10 minutes; otherwise, the core IGBT module will be completely destroyed by the accumulated heat.
- For E8XX Wire Feed Alarms, Check Externally First: When an E800-level wire feeding error occurs, do not immediately suspect the mainboard. The vast majority of cases are caused by wire jamming due to a worn contact tip, iron filings clogging the wire liner, or a snapped control cable.
2. DM350 / DM500 Core Error Codes Quick Reference Table
The following is the official OTC troubleshooting logic. If plugging or unplugging internal PC board connectors (such as the P10263U) is involved, it must be performed by professionals after powering off and waiting for 5 minutes (for capacitor discharge).
| Error Code | Fault Name | Inducing Cause Analysis | Official Troubleshooting Solution |
|---|---|---|---|
| dAIHEn | Anti-Accidental Touch Safety Circuit Activated | The torch trigger was pressed or jammed at the exact moment of power-on. Output is cut off to prevent accidental arc ignition. | Release and disconnect the torch trigger; the safety circuit will be cleared and return to normal. |
| E000 | External Stop Terminal Open Circuit | The “Work Stop Terminal” (wire number 143) on the 12P (TM1) external connection terminal block is open and not short-circuited. | Turn off the power, short-circuit the aforementioned terminal (if not in a dedicated robot machine mode), and restart. |
| E100 | Control Power Supply Error | The internal control power supply experienced momentary interference or abnormal fluctuations. | Turn off the power and turn it on again; this usually clears the error directly. |
| E200 | Current Transformer Error | Poor connection of the primary/secondary current transformer, or the sensor is damaged. | Power off, check if connectors CN8 and CN9 on the P10263U PC board are loose, and reseat them firmly. |
| E210 | Voltage Detection Wire Error | The output voltage detection wire (+) or the wire feeder control cable is damaged or has poor contact. | Check the 10-core control cable for broken wires. Reseat CN3, 6, and 10 on the P10264T PC board. |
| E300 | Exceeded Duty Cycle (Over-Temperature) | Continuous high-current welding exceeds the machine’s rated duty cycle, and the internal thermostat forcefully disconnects for protection. | Keep the power on! Allow the fan to force-cool for at least 10 minutes, and reduce the operating current before welding again. |
| E600 | Battery Replacement Warning | The coin-cell battery on the mainboard used for memorizing welding parameters is nearly depleted. | Press any key to clear; it does not affect welding. Please contact the agent as soon as possible to replace it with a genuine original battery to prevent parameter loss. |
| E700 | Output Overcurrent Error | Overcurrent during welding for more than 1 second, or the secondary cable is short-circuited, or the contact tip is in direct dead contact with the workpiece. | Check if the contact tip has melted and stuck, and if the cable insulation is broken. Restart after eliminating the short-circuit point. |
| E710 | Input Phase Loss Error | Phase loss occurs in the factory’s primary input grid (e.g., one of the phase wires is disconnected). | Use a multimeter to check the three-phase voltage at the workshop wall switch. Repair the facility wiring before powering on. |
| E800 | Wire Feeder Encoder Error | The feedback encoder signal at the rear of the wire feeder is lost. | Check if the encoder’s 4-pin plug or the 10-core long control cable is broken. If the wires are intact, replace the P10261Q PC board. |
| E810 | Motor Drive Circuit Overheated | The temperature of the P10261Q PC board is too high, or a severe short circuit has occurred in the motor cable. | Check if the PC board is burned out, and troubleshoot whether the internal cables of the wire feeder have a grounding short circuit. |
| E820 | Motor Overcurrent Warning (Standby Display) | Excessive wire feeding resistance causes the wire feed motor load to exceed 70% of its rating. This is a precursor to wire jamming! | Immediately clean or replace the wire feed hose (liner), replace the worn contact tip, and check the tension of the drive rolls. |
| E830 | Motor Overcurrent Error (Forced Shutdown) | Resistance severely exceeds the standard, causing the motor to stall, or the motor power supply wire has short-circuited. | Comprehensively troubleshoot for severe wire jamming from the wire feeder to the torch head. Clean out debris and replace worn parts. |
| E9XX | Microprocessor Crash Fault | An irreversible hardware or program failure has occurred in the mainboard CPU or control chip. | If powering off and restarting is ineffective, you must contact an officially authorized agent to order a brand-new main control board for replacement. |