Miller Migmatic 175, Owner'S Manual

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OM-259 158 Page 9
duty1 4/95 − SB-150 215
250
200
150
100
30 40 50 60 70 80 90 100
50
35 25
Rated Output
6 minutes welding 4 minutes resting
Duty Cycle is a 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 be-
fore welding.
NOTICE − Exceeding duty cycle can
damage unit or gun and void warranty.
Overheating
0
15
OR
reduce duty cycle
Minutes
100% Duty Cycle at 60 Amperes
A or V
60% Duty Cycle at 100 Amperes
% DUTY CYCLE
3-4. Duty Cycle and Overheating
Continuous Welding
3-5. Volt-Ampere Curves
Model 175
50 100 150 200
40
30
20
10
1 Normal Volt-Amperage Curves
The volt-ampere curves show the nor-
mal minimum and maximum voltage
and amperage output capabilities of
the welding power source. Curves of
other settings fall between the curves
shown.
2 Overload Volt-Ampere Curves
When unit is beyond capacity, circuitry
senses the overload and shuts down
unit output. Release trigger and lower
weld voltage setting before trying to
weld. This shut down circuitry protects
internal circuits and parts from over-
load damage.