Miller STi 270, Owner'S Manual

Page: 12 / 44

OM-263 706 Page 8
3-4. Volt-Ampere Curves
Volt-ampere curves show minimum and maximum voltage
and amperage output capabilities of welding power source.
Curves of other settings fall between curves shown.
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
DC Amperage (A)
DC Voltage (V)
All Models
0 10 20 30 40 50 60 70 80 90 100 120 130140 150 160 170180 190200 210 220 230240 250 260270280 110
3-5. Duty Cycle And Overheating
Duty Cycle is percentage of 10 min-
utes that unit can weld at rated load
without overheating.
If unit overheats, output stops and
cooling fan runs. Wait fifteen min-
utes for unit to cool. Reduce amper-
age 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
4 Minutes Welding 6 Minutes Resting
50
100
150
200
250
300
10 100
STICK/TIG
50
Output Amperes
270 Amps @ 40% Duty Cycle
180 Amps @ 100% Duty Cycle