This Korean Industrial Standard specifies a.c. arc welders of light duty and low duty cycle, hereinafter referred to as the "welders", among a.c. arc welders mainly consisting of a single phase transformer at a frequency of 60Hz. This standard also specifies such welders that the welding current is regulated only by tap changing, hereinafter referred to as the "tap-type welders", if necessary to be distinguished from others. This standard does not specify the attached devices (such as electric shock preventing devices and remote current control devices) integrated in welders.