Arc Machines 307 - Manual (Page 111)

Arc Machines, Inc. Model 307 Orbital Tube Welder Training
Document No. 740096 Chapter 9. Page 7.
Rev. A
Level Amps: Typically, the heat required to achieve penetration
at the beginning of a weld will need to be reduced during the
weld to avoid overpenetration. There are several methods of cal-
culating intermediate level Primary Amps.
1.The first method works for any number of levels. If the
amperage is reduced by 20% from Level 1 to the Last Level,
then the Last Level will be equal to 80% of Level 1. To calcu-
late the amount of primary amp reduction for each level, sub-
tract the Last Level amps from Level 1 amps and divide the
difference by the number of levels you are creating minus 1
level.
“Real World” Level 1 Primary Amperage Calculations
Wall Thickness
(in).
Primary Level 1
Amps based on 1
amp per 0.001”
% Correction Primary
Amps based
on
correction
0.035 35 Amps 0 35 Amps
0.049 49 Amps +10 54 Amps
0.065 65 Amps +15 75 Amps
0.083 83 Amps +15 96 Amps
0
20
40
60
80
100
120
0.035 0.049 0.065 0.083 0.109 0.12
Wall Thickness - Inches
Am
ps
1 Amp per 0.001”
Correction
Primary Amps/Wall Thickness