Table 3-2. Maximum Wire Lengths to Limit Voltage Drops
Wire Size
Cross Section
Resistivity
Maximum Length in Meters (Feet) to Limit
Voltage Drop to 0.5 V or Less
AWG Area in mm2
22
0.5
20
0.75
18
1
16
1.5
14
2.5
12
4
10
6
8
10
6
16
4
Ω/kft Ω/km
16.15
40.1
10.16
26.7
6.388
20.0
4.018
13.7
2.526
8.21
1.589
5.09
0.9994
3.39
0.6285
1.95
0.3953
1.24
0.2486
5 A
(6)
2.5
(9.5)
3.7
(15.5)
5.0
(24.5)
7.3
(39.5)
12.2
(62.5)
19.6
(100)
29
(159)
51
(252)
80
(402)
10A
(3)
1.2
(4.5)
1.9
(7.5)
2.5
(12)
3.6
(19.5)
6.1
(31)
9.8
(50)
14.7
(79)
25
(126)
40
(201)
20A
(1.5)
0.6
(2)
0.9
(3.5)
1.3
(6)
1.8
(9.5)
3.0
(15.5)
4.9
(25)
7.4
(39.5)
12.8
(63)
20
(100)
30A
(1)
0.4
(1.5)
0.6
(2.5)
0.8
(4)
1.2
(6.5)
2.0
(10.5)
3.3
(17)
4.9
(27)
8.5
(40)
13.4
(68)
40A (0.77) 0.31 (1.23) 0.47 (2.0) 0.63 (3.1) 0.91 (4.9) 1.52 (7.9) 2.46 (12.5) 3.69 (19.9) 6.41 (31.6) 10.08 (50.37)
50A (0.62) 0.25 (0.98) 0.37 (1.57) 0.50 (2.49) 0.73 (3.46) 1.22 (6.29) 1.96 (10.00) 2.95 (15.91) 5.13 (25.30) 8.06 (40.23)
60 A
(0.52)
0.21
(0.82)
0.31
(1.30)
0.42
(2.07)
0.61
(3.30)
1.01
(5.24)
1.64
(8.34)
2.96
(13.25)
4.27
(21.07)
6.72
(33.51)
Zero-Volt Loading Connections
As shown in Figure
