In industrial aluminum welding and precision TIG welding applications, the OTC DAIHEN VRTP400III(S-3) TIG Welder is an extremely core piece of equipment. To ensure production continuity, when the equipment experiences issues such as main power trips, failure to strike an arc, no high-frequency (HF) generation, or abnormal panel alarms, equipment maintenance personnel can refer to the following detailed troubleshooting charts for localization and resolution.
I. VRTP400 TIG Welder Common Faults & Troubleshooting
Please refer to the specific phenomena and panel indicator statuses in the table below to perform the corresponding inspection and maintenance operations:
| No. | Fault Phenomenon | Cause of Fault / Abnormality | Troubleshooting Measure | ||
|---|---|---|---|---|---|
| 1 | Power switch NF trips | There may be a severe short circuit inside the equipment. Absolutely DO NOT re-energize it! Please contact your agent immediately. | |||
| 2 | Main power indicator PL1 is OFF | Indicator PL1 bulb fault | Check and replace PL1 | ||
| Phase loss in input wiring | Check distribution box fuses and wiring | ||||
| 3 | Power switch NF turned ON, but fan FM does not run | Fan FM fault | Check and replace FM | ||
| Phase loss on input side | Check distribution box fuses and wiring | ||||
| 4 | Cannot adjust welding current shown on digital display from the panel | Remote control pendant is connected | Disconnect the remote control and try again | ||
| Hall current sensor CT2 fault | Check and replace CT2 | ||||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| PCB8 circuit board fault | Check and replace PCB8 | ||||
| Digital meter DM fault | Check and replace DM | ||||
| 5 | Cannot adjust current from the remote control pendant | Remote control body fault | Check and replace remote control | ||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| 6 | Abnormal Indicator PL2 is ON | LED1 on PCB1 is ON | Inverter side heatsink temp abnormal, or DCL side temp abnormal | Reduce duty cycle and wait for cooling | |
| LED2 on PCB1 is ON | CN28 connector on PCB1 has fallen off | Check and insert CN28 firmly | |||
| LED3 on PCB1 is ON | Input phase loss | Check distribution box wiring | |||
| LED4 on PCB1 is ON | Insufficient water pressure or pressure switch fault | Check water cooler (ensure pressure at switch is >0.06MPa) or replace pressure switch | |||
| LED5 on PCB1 is ON | Torch switch is ON when power switch is turned on | Turn off the torch switch | |||
| LED6 on PCB1 is ON | Input voltage too high | Please use a standard 380V distribution box | |||
| Other Statuses | Abnormal Stop | Check if CN102 on PCB1 is shorted between ① and ② | Remove short if applicable | ||
| PCB1 fault | Check and replace PCB1 | – | |||
| Gas check time too long | Turn off gas check switch and restart welder | – | |||
| 7 | Digital display is OFF | CN24 connector on PCB1 has fallen off | Check CN24 connection | ||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| Auxiliary transformer T2 fault | Check and replace T2 | ||||
| 8 | No Arc Ignition | Poor contact in output side wiring | Check output wiring | ||
| IGBT modules TR1, TR2 fault | Check and replace TR1, TR2 | ||||
| Fast recovery diode (FRD) DR2, DR3 fault | Check and replace DR2, DR3 | ||||
| Three-phase rectifier bridge DR1 fault | Check and replace DR1 | ||||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| 9 | Initial current cannot be adjusted from the control panel | Toggle switch DS1(1/6) on PCB1 is on the ON side | Flip DS1(1/6) to the OFF side | ||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| 10 | No shielding gas flows when torch switch is pressed | Cylinder valve is not open | Open cylinder valve | ||
| Insufficient cylinder pressure | Check gas pressure and replace cylinder | ||||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| Gas solenoid valve fault | Check and replace solenoid valve | ||||
| 11 | No High-Frequency (HF) Spark Generated Between Electrode and Workpiece | Spark discharge sound is heard inside the power source | Electrode oxidized/whitened | Re-grind the electrode | |
| TB1, TB2 connectors on PCB5 fallen off | Insert TB1, TB2 connectors firmly | ||||
| No spark discharge sound inside the power source | Mistakenly set to MMA (Stick) mode | Please switch to TIG or Spot Welding mode | |||
| PCB1 or PCB5 fault | Check and replace PCB1 or PCB5 | ||||
| Auxiliary transformer T2 fault | Check and replace auxiliary transformer | ||||
| Cement resistor R12 fault | Check and replace cement resistor R12 | ||||
| Internal connector fallen off | Check if CN3 on PCB1 or CN1/CN2 on PCB5 has fallen off | ||||
| 12 | In TIG “Water-Cooled Torch” mode, no response when pressing torch switch | Abnormal indicator PL2 is ON | Insufficient water pressure | Check and increase water pressure | |
| Abnormal indicator PL2 is OFF | Torch switch fault | Check and replace torch switch | |||
| PCB1 circuit board fault | Check and replace PCB1 | ||||
| 13 | Generates HF when pressing torch switch but fails to strike arc | Arc appears if electrode touches workpiece | Electrode oxidized/whitened | Re-grind the electrode | |
| Electrode too thick or set current too low | |||||
| Select correct tungsten diameter and reset reasonable current | |||||
| Switch to MMA mode, no open-circuit voltage output | Inverter main circuit fault | Turn off power switch, contact agent | |||
| Switch to MMA mode, has open-circuit voltage output | PCB1 circuit board fault | Check and replace PCB1 | |||