Square Wave Operation - ESAB Heliarc 252 Instruction Manual

SECTION 3
MAXIMUM STRAIGHT POLARITY
MINIMUM TUNGSTEN HEATING
Figure 3-2. Square Wave Operation
IMPORTANT: When using "Maximum Penetration" in AC Tig; the duty
cycle will be reduced 50% and input current will increase
approximately 40%. Also, when DC T ig welding, the Balance
Control should always be set to the Maximum Cleaning
(balanced wave) position.
NOTE: Square wave power sources generally offer better cleaning in AC tig
welding than conventional saturable reactor machines. T he extra clean-
ing results from more reverse polarity which decreases the maximum
current for a given electrode. The following may help to resolve this
situation: (1) Adjust the balance control for less cleaning, (2) use a
larger electrode, and (3) use 2% thoriated tungsten.
26
OPERATION