Type of Output Current:

Either alternating current (AC) or direct current (DC) might be employed for shielded metal arc welding, based upon the current supplied by the power source and the electrode decided. The particular type of current employed influences the performance of the electrode. Each current type has its limitations and advantages, and these must be considered while selecting the type of current for a particular application. Factors which have to be considered are as follows :

Voltage Drop

In the welding cables ,voltage drop is lower with AC. It makes AC more appropriate if the welding is to be done at long distances through the power supply. However, long cables that carry AC must not be coiled because the inductive losses encountered in such cases might be substantial.

Low Current

With and low welding currents and small diameter electrodes, DC provides better operating characteristics and a more stable arc.