Inadequate or poor grounding can have a negative effect on your welding. A frayed ground clamp or a ground lying on the workpiece increases the resistance in the welding circuit. In the case of GMAW or FCAW, this requires the output to be increased to achieve the same current or voltage. This also becomes a problem if you are not using the proper cable size for your application. For example, if welding at 300 amps with 200 feet of 2/0 cable, to achieve 25 volts at the arc, the machine voltage output will need to be almost 31 volts!

Always ground as close to the weld as possible. If the ground is getting warm during welding, you have excess resistance in the welding circuit or undersized cable. In the application of pulse welding, this issue is often overlooked, and the result is inconsistencies in the arc. Be sure to use a “C” clamp type ground clamp or bolt the ground to the fixture if possible. Never pulse weld with a common ground through several tables. This will have a negative effect on the arc characteristics as well.