Amps | 100' | 150' | 200' | 250' | 300' | 350' | 400' |
---|---|---|---|---|---|---|---|
100 | 4 | 4 | 2 | 2 | 1 | 1/0 | 1/0 |
150 | 4 | 2 | 1 | 1/0 | 2/0 | 3/0 | 3/0 |
200 | 2 | 1 | 1/0 | 2/0 | 3/0 | 4/0 | 4/0 |
250 | 1 | 1/0 | 2/0 | 3/0 | 4/0 | - | - |
300 | 1/0 | 2/0 | 3/0 | 4/0 | - | - | - |
350 | 1/0 | 3/0 | 4/0 | - | - | - | - |
400 | 2/0 | 3/0 | - | - | - | - | - |
450 | 2/0 | 4/0 | - | - | - | - | - |
500 | 3/0 | 4/0 | - | - | - | - | - |
550 | 3/0 | 4/0 | - | - | - | - | - |
600 | 4/0 | - | - | - | - | - | - |
* The total circuit length includes both welding and ground leads (based on 4-volt drop) 60% duty cycle.
These values for current-carrying capacity are based on a copper temperature of 60C (140F), an ambient temperature of 40C (104F), and yield load factor of approximately 32% from the 2 AWG cable, approximately 23% for the 3/0 AWG cable and higher for the smaller sizes.
The sizes of cables generally used ranged from 2 AWG to 3/0 AWG. In actually service, the load factor may be much higher than indicated without overheating the cable as the ambient temperature will generally be substantially lower than 40C.
AWG | AMPERES | AWG | AMPERES |
---|---|---|---|
4/0 | 315 | 1 | 170 |
3/0 | 275 | 2 | 150 |
2/0 | 235 | 3 | 130 |
1/0 | 200 | 4 | 110 |
- | - | 6 | 85 |
Per standards: ICEA S-19-81
NEMA WC-3 Part 8, Appendix J
Ampacities for portable cable, continuous duty (Ambient Temperature of 40C)