|
Voltage Drop Chart
Maximum distance in feet of various gauge two conductor copper wire from
power source to load for 2% voltage drop in a 12 volt system. Do not exceed
the 2% drop for wire between PV modules and batteries. A 4 to 5% loss
is acceptable between batteries and lighting circuits in most cases.
Voltage Drop Chart
| Amps |
#14 |
#12 |
#10 |
#8 |
#6 |
#4 |
#2 |
#1/0 |
#2/0 |
#4/0 |
| 1 |
45 |
70 |
115 |
180 |
290 |
456 |
720 |
. |
. |
. |
| 2 |
22.5 |
35 |
57.5 |
90 |
145 |
228 |
360 |
580 |
720 |
1060 |
| 4 |
10 |
17.5 |
27.5 |
45 |
72.5 |
114 |
180 |
290 |
360 |
580 |
| 6 |
7.5 |
12 |
17.5 |
30 |
47.5 |
75 |
120 |
193 |
243 |
380 |
| 8 |
5.5 |
8.5 |
11.5 |
22.5 |
35.5 |
57 |
90 |
145 |
180 |
290 |
| 10 |
4.5 |
7 |
11.5 |
18 |
28.5 |
45.5 |
72.5 |
115 |
145 |
230 |
| 15 |
3 |
4.5 |
7 |
12 |
19 |
30 |
48 |
76.5 |
96 |
150 |
| 20 |
2 |
3.5 |
5.5 |
9 |
14.5 |
22.5 |
36 |
57.5 |
72.5 |
116 |
| 25 |
1.8 |
2.8 |
4.5 |
7 |
11.5 |
18 |
29 |
46 |
58 |
92 |
| 30 |
1.5 |
2.4 |
3.5 |
6 |
9.5 |
15 |
24 |
38.5 |
48.5 |
77 |
| 40 |
. |
. |
2.8 |
4.5 |
7 |
11.5 |
18 |
29 |
36 |
56 |
| 50 |
. |
. |
2.3 |
3.6 |
5.5 |
9 |
14.5 |
23 |
29 |
46 |
| 100 |
. |
. |
. |
. |
2.9 |
4.6 |
7.2 |
11.5 |
14.5 |
23 |
| 150 |
. |
. |
. |
. |
. |
. |
4.8 |
7.7 |
9.7 |
15 |
| 200 |
. |
. |
. |
. |
. |
. |
3.6 |
5.8 |
7.3 |
11 |
|
Maximum Ampacity for Copper and Aluminum Wire
| Wire Size |
Copper |
Aluminum |
| 14 |
25 |
. |
| 12 |
30 |
25 |
| 10 |
40 |
35 |
| 8 |
55 |
45 |
| 6 |
75 |
60 |
| 4 |
95 |
75 |
| 2 |
130 |
100 |
| 1 |
150 |
115 |
| 1/0 |
170 |
135 |
| 2/0 |
265 |
150 |
| 4/0 |
360 |
205 |
|
NEC allows rounding up cable ampacity to next standard
fuse or breaker.
|
