Carries head and controls in either direction on a beam of suitable length. It operates either automatically with the weld controls or manually. The speed range, set with a continuous speed control without gear changes, is 5-75 ipm (.1-1.9 m/min). Requires 115V AC, 60 or 50 hertz power available from Lincoln power sources. For tandem arc (2 or 3 heads) and Twinarc®-tandem arc (up to 4 wires) installations.