Arc Machines 307 User Manual

Page 50

Arc Machines, Inc. Model 307 Orbital Tube Welder Training

Document No. 740096

Chapter 5. Page 1.

Rev. May 2005

hapter 5. Model 307 Weld Parameters/

Sequence of Events

his chapter will explain the Sequence of Events that

takes place during a weld. Every size of tube, pipe, fitting,

or other component to be welded must have a written

weld schedule or weld program that defines what each

of the various weld parameters controlled by the power

supply will be at each phase or level of the sequence. The

effect that each parameter has on the weld will be ex-

plained.

The weld sequence or "sequence of events" begins

when the operator presses the Start button on the Model

307 touch screen from the Weld Schedule - Weld Screen in

Weld Mode. This initiates a timed Prepurge during which

an inert shield gas is supplied to the weld head. Gas con-

tinues to flow throughout the weld sequence and during a

timed Postpurge which begins at the end of Downslope.

At the end of prepurge the arc is initiated. The current at

which the arc is struck will be the value set for Start Lev-

el. Current (amps) may be programmed to advance from

PREPURGE

SEQUENCE

ART

LEVEL

POSTPURGE