Burnback duration during GMA welding

When the welding operation is ended, the trailing of the wire electrode must be taken into account so that, after the extinction of the arc, the wire electrode end is not immersed in the molten metal and does not get stuck in it, Fig. 1. For this purpose, most GMA welding installations are equipped with an electronic switching system, Fig. 2. This means that, when the welding operation is ended, the wire feed is switched off by actuating the torch switch while the welding current still remains switched on for a short time. Thus, the wire electrode can melt back a little and does not get stuck in the molten metal.