Miller Electric 1251 Welder User Manual


 
. A complete Parts List is available at www.MillerWelds.com
OM-201 872 Page 11
4-2. Duty Cycle and Overheating
Duty Cycle is percentage of 10
minutes that unit can cut 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 duty cycle before cutting.
Y Exceeding duty cycle can
damage unit and void war-
ranty.
Overheating
0
15
A
OR
Reduce Duty Cycle
Minutes
duty1 4/95
230 Volts AC Three-Phase Input Power:
50% Duty Cycle
208 Volts AC Three-Phase Input Power:
40% Duty Cycle
380-575 Volts AC Three-Phase Input Power:
80% Duty Cycle
5 Minutes Cutting 5 Minutes Resting 8 Minutes Cutting 2 Minutes Resting
4 Minutes Cutting 6 Minutes Resting
4-3. Cutting Speed
The cutting speed curve shows the
rated cutting speed capabilities of
the power source and torch for mild
steel, stainless steel, and aluminum
of various thicknesses.
Y Exceeding recommended
cutting speeds will cause
rapid erosion of the tip and
electrode.
Rated Cutting Speed vs Material Type & Thickness
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
0.25” 0.375” 0.5” 0.625” 0.75” 1” 1.25”
Material Thickness (Inches)
Cutting Speed (Inches per Minute)
Aluminum Stainless Steel Mi ld Steel