Miller Electric 250 Welder User Manual


 
OM-353 Page 24
4-9. Arc Controls
1 Arc Control (Dig)
For AC And DC SMAW Welding
When set at 0, short-circuit amper-
age at low arc voltage is the same
as normal welding amperage.
When setting is increased, short-
circuit amperage at low arc voltage
increases.
Set at 0 for GTAW welding.
2 Arc Control Switch
Place switch in the ON position to
turn on arc control circuitry. When
switch is in the OFF position, no ad-
ditional amperage is available at
low arc voltages. Place switch in
the OFF position while performing
Gas Tungsten Arc Welding
(GTAW).
Application:
Control helps arc starting or making
vertical or overhead welds by in-
creasing amperage at low arc volt-
age, and reduces electrode sticking
while welding.
2
1
4-10. Postflow Time Control
1 Postflow Time Control
Use control to set length of time
(070 seconds) gas flows after
welding stops. It is important to set
enough time to allow gas to flow un-
til after the tungsten and weld
puddle has cooled down.
Application:
Postflow is required to cool tung-
sten and weld, and to prevent con-
tamination of tungsten and weld. In-
crease postflow time if tungsten or
weld are dark in appearance.
1