[Cause]
The voltage feedback (voltage feedback value) remains below the displayed voltage value for at least the arc-loss detection time. The robot therefore determines that the arc has been lost.
[Countermeasure]
Eliminate the cause of the voltage drop. If welding is otherwise normal, the voltage threshold for arc-loss detection may be too high. In that case, decrease $AWEUPR[eq].$ARC_LOSS_V (eq indicates the equipment number).