MAWA-050A
8. Troubleshooting
8-5
(3)
Error other than Above
If the buzzer of the main unit sounds intermittently as “bleep, bleep, bleep”, make contact with us.
(4)
Check Items when LOST Error Has Occurred
When an arc discharge (*1) does not occur at the time of welding start or welding modulation, etc.
and a welding is not performed as preset, it is called LOST (= misfire).
When LOST has occurred, check the following items:
Ground
connection of workpiece
Confirm that the welding workpiece and the grounding terminal of the welding power supply is surely
connected. When a ground connection is poor, LOST occurs.
[Reference case]
When a ground connection was performed by clamping the welding workpiece, the contact failure
caused by contamination on the contact surface of workpiece and clamp occurred and the LOST
error frequently occurred.
By removing contamination on the contact surface of clamp as a measure, the occurrence of the
LOST error was improved.
Flow rate setting of argon gas
When the welding current value of welding condition settings is set to approx. 15 A or lower and the
flow rate of argon gas is high, LOST occurs.
[Reference case]
When 5 A of initial current value, 10 A of pulse current value and 5 L/min of argon gas flow rate were
set, the LOST error frequently occurred when the electrode was detached from the workpiece at the
time of initial current or at the time of occurrence of the creeping-up (*2).
By changing the flow rate of argon gas to approx. 0.5 to 1.0 L/min according to the welding current
value as a measure, the occurrence of the LOST error was improved.
Consumption and contamination of electrode tip
When argon gas is not supplied at welding, the consumption of electrode tip becomes large and the
electrode tip is coated with oxide and insulated, and therefore LOST occurs.
[Reference case]
When a welding was performed without supplying argon gas, the consumption of electrode tip
became large and the electrode tip was coated blackly with oxide and insulated, and therefore the
touch start function became disabled and the LOST error frequently occurred.
By supplying argon gas according to the welding condition as a measure, the occurrence of the
LOST error was improved.
*1: “Arc discharge” is a kind of plasma and a discharging style sustained by thermionic emission of
electrons from the high-temperature electrodes. Since an arc conducts electricity, electricity
flows through an arc once an arc is generated. Due to an oxide of electrode or ions and
electrons of argon gas surrounding the electrodes by high-temperature heat generation at that
time, an arc is generated and an arc discharge is put in a stable state.
*2: “Creeping-up” means that the position of arc discharge moves from the electrode tip to the side
