1. Welding machine does not work when foot pedal is depressed, power indicator light does not illuminate:
a. Check if the power supply voltage is normal; check if the control system is normal.
b. Check if the foot switch contacts, AC contactor contacts, and tap changer switches are making good contact or are burnt out.
2. Power indicator light illuminates, workpiece is pressed but welding fails:
a. Check if the foot pedal travel is complete and if the foot switch is making good contact.
b. Check if the pressure rod spring screw is properly adjusted.
3. Unexpected spatter occurs during welding:
a. Check if the electrode tip is severely oxidized.
b. Check if the workpiece is severely corroded and has poor contact.
c. Check if the adjustment switch is set too high.
d. Check if the electrode pressure is too low and if the welding program is correct.
4. Severe weld indentation with extruded material:
a. Check if the current is too high.
b. Check if the workpiece is uneven.
c. Check if the electrode pressure is too high and if the electrode tip shape and cross-section are appropriate.
5. Insufficient weld strength:
a. Check if the electrode pressure is too low and if the electrode rod is securely fastened.
b. Check if the welding energy is too low and if the workpiece is severely corroded, causing poor weld contact.
c. Check for excessive oxides between the electrode head and electrode rod, and between the electrode rod and electrode arm.
d. Check if the electrode head cross-section has increased due to wear, resulting in reduced welding energy.
e. Check for severe oxidation at the electrode and copper flexible connector mating surfaces.
6. Abnormal AC contactor noise during welding:
a. Check if the AC contactor's input voltage is lower than its own discharge voltage of 300 volts during welding.
b. Check if the power supply leads are too thin or too long, causing excessive voltage drop.
c. Check if the main grid voltage is too low, preventing normal operation.
d. Check if the main transformer is short-circuited, causing excessive current.
7. Overheating of the welding machine:
a. Check if the insulation resistance between the electrode holder and the machine body is poor, causing a partial short circuit.
b. Check if the inlet water pressure, water flow rate, and water supply temperature are appropriate. Check if there is any dirt or blockage in the water system, which could cause overheating of the electrode arm, electrode rod, and electrode head due to poor cooling.
c. Check if the contact surfaces of the copper flexible connector, electrode arm, electrode rod, and electrode head are severely oxidized, causing increased contact resistance and severe overheating.
d. Check if the cross-sectional area of the electrode head has increased excessively due to wear, causing the welding machine to overload and overheat.
e. Check if the welding thickness and duty cycle exceed the limits, causing the welding machine to overload and overheat.