This standard specifies requirements for the design, performance and rating of rotating a.c. and/or d.c. electric arc welding power sources (hereinafter referred to as 'welding power source') consisting of alternators or generators with suitable control for regulating welding current, and driven by electric motors, internal combustion engines or mechanical drives from separate prime movers.This standard does not include requirements for connected equipment such as welding leads, electrode holders and automatic wire feeders, etc.