Operating instructions
004 859 Page 7
MAXIMUM CABLE
CAPACITY BASED
ON TEMPERATURE RISE
8
6
4
2
1
1/0
2/0
3/0
4/0
(2) 2/0
(2) 3/0
(2) 4/0
(2) 4/0
(3) 3/0
(3) 4/0
(4) 4/0
(4) 4/0
900 MCM
1000 MCM
60
90
120
240
300
360
450
540
640
710
780
860
940
1090
1220
1340
1450
1540
1630
CABLE AMPS
VOLTS
LOSS
IN
CABLES
25
20
15
10
9
8
7
6
5
4
3.5
3
2.5
2
1.5
RECOMMENDED
LOSS ALLOWED
4 VOLTS OR LESS
8
AWG
CABLE
SIZE
1000
4/0
4
5
6
7
3
2
1
1/0
2/0
3/0
(3) 3/0
(4) 4/0
(3) 4/0
(2) 4/0
(2) 2/0
(2) 3/0
FOR AC USE NEXT
LARGER CABLE SIZE
MCM
20
2000
100
400
200
50
40
30
200
300
1000
600
500
800
1200
1400
1600
1800
2000
150
100
300
250
AMPERES
900
800
1000
1500
400
500
600
700
TOTAL LENGTH
OF CABLES
IN FEET
Reference Line
Figure 3-1. Nomogram For Computing Weld Cable Size
3-3. Using the Nomogram
A. Example 1
The welding current will be 200 amperes DC. The work lead is 190 feet long while the electrode lead is 210 feet long. The total lead length is 400 feet.
Draw a straight line from 200 amperes through 400 feet and intersect the reference line. Draw a straight line from the reference intersection through and
cable size that will give less than a 4 volt loss. In this example, a 4/0 cable will give a 3.9 volt loss. Check this cable size in the maximum current capacity
table. It shows a 4/0 cable has a maximum capacity of 640 amperes, well above the 200 amperes used in this example.
The solution: Use 4/0 weld cable for the connections.