Miller MigMatic 220, Owner'S Manual

Page: 13 / 56

OM-246 691 Page 9
3-4. Duty Cycle And Overheating
Duty Cycle is percentage of 10 min-
utes that unit can weld at rated load
without overheating.
If unit overheats, thermostat(s)
opens, output stops, and cooling
fan runs. Wait fifteen minutes for
unit to cool. Reduce amperage or
voltage, or duty cycle before
welding.
NOTICE − Exceeding duty cycle
can damage unit and void warranty.
Overheating
0
15
A or V
OR
Reduce Duty Cycle
Minutes
35% Duty Cycle At 250 Amperes 100% Duty Cycle At 145 Amperes
sduty1 5/95
% DUTY CYCLE
Continuous Welding 3-1/2 Minutes Welding 6-1/2 Minutes Resting
3-5. Volt-Ampere Curves
The volt-ampere curves show the normal minimum and maximum voltage and amperage output capabilities of the welding power source. Curves
of other settings fall between the curves shown.
Model 250
MIN
MAX
Model 220