Section Index Owatonna Steele County Amateur Radio 06-Aug-2015

2% Wire Loss Chart

In a low voltage system, the maximum voltage drop in the power cables should be less than 2%.
For a nominal 12 volt circuit, a 2% loss represents 0.25 volts.

 This chart estimates the maximum distance of a two conductor copper cablefrom the power source to the load resulting in a 2% voltage drop. Wire Size Amps #18 #16 #14 #12 #10 #8 #6 #4 1 18 29 47 74 118 187 298 474 2 9 15 23 37 59 94 149 237 3 6 10 16 25 39 62 99 158 4 5 7 12 19 29 47 74 119 5 4 6 9 15 24 37 60 95 6 3 5 8 12 20 31 50 79 7 3 4 7 11 17 27 43 68 8 2 4 6 9 15 23 37 59 9 2 3 5 8 13 21 33 53 10 2 3 5 7 12 19 30 47 15 1 2 3 5 8 13 20 32 20 1 2 2 4 6 9 15 24 25 1 1 2 3 5 8 12 19 30 1 2 3 4 6 10 16 35 1 2 3 5 8 14 40 1 2 3 5 7 12 45 1 2 3 4 7 11 50 1 2 2 4 6 10

 This chart estimates the voltage drop of a two conductor copper cablefrom the power source to the load. Wire Size Amps #18 #16 #14 #12 #10 #8 #6 #4 1 0.128 0.080 0.051 0.032 0.020 0.013 0.008 0.005 2 0.255 0.161 0.101 0.064 0.040 0.025 0.016 0.010 3 0.383 0.241 0.152 0.095 0.060 0.038 0.024 0.015 4 0.511 0.321 0.202 0.127 0.080 0.050 0.032 0.020 5 0.639 0.402 0.253 0.159 0.100 0.063 0.040 0.025 6 0.766 0.482 0.303 0.191 0.120 0.075 0.047 0.030 7 0.894 0.562 0.354 0.222 0.140 0.088 0.055 0.035 8 1.022 0.643 0.404 0.254 0.160 0.101 0.063 0.040 9 1.149 0.723 0.455 0.286 0.180 0.113 0.071 0.045 10 1.277 0.803 0.505 0.318 0.200 0.126 0.079 0.050 15 1.916 1.205 0.758 0.476 0.300 0.188 0.119 0.075 20 2.554 1.606 1.010 0.635 0.400 0.251 0.158 0.099 25 3.193 2.008 1.263 0.794 0.499 0.314 0.198 0.124 30 3.831 2.410 1.515 0.953 0.599 0.377 0.237 0.149 35 4.470 2.811 1.768 1.112 0.699 1.440 0.277 0.174 40 5.108 3.213 2.020 1.270 0.799 0.503 0.316 0.199 45 5.747 3.614 2.273 1.429 0.899 0.565 0.356 0.224 50 6.385 4.016 2.525 1.588 0.999 0.628 0.395 0.249

 This chart estimates the power loss (Watts) in a two conductor copper cablefrom the power source to the load. Wire Size Amps #18 #16 #14 #12 #10 #8 #6 #4 1 0.128 0.080 0.051 0.032 0.020 0.013 0.008 0.005 2 0.511 0.321 0.202 0.127 0.080 0.050 0.032 0.020 3 1.149 0.723 0.455 0.286 0.180 0.113 0.071 0.045 4 2.043 1.285 0.808 0.508 0.320 0.201 0.126 0.080 5 3.193 2.008 1.263 0.794 0.499 0.314 0.198 0.124 6 4.597 2.892 1.818 1.143 0.719 0.452 0.284 0.179 7 6.257 3.936 2.475 1.556 0.979 0.616 0.387 0.244 8 8.173 5.140 3.232 2.033 1.279 0.804 0.506 0.318 9 10.34 6.506 4.091 2.573 1.618 1.018 0.640 0.403 10 12.77 8.032 5.050 3.176 1.998 1.256 0.790 0.497 15 28.73 18.07 11.36 7.146 4.495 2.827 1.778 1.118 20 51.08 32.13 20.20 12.70 7.991 5.026 3.161 1.988 25 79.81 50.20 31.56 19.85 12.49 7.853 4.939 3.106 30 114.9 72.29 45.45 28.58 17.98 11.31 7.112 4.473 35 156.4 98.39 61.86 38.91 24.47 15.39 9.680 6.088 40 204.3 128.5 80.80 50.82 31.97 20.10 12.64 7.952 45 258.6 162.6 102.3 64.31 40.46 25.44 16.00 10.06 50 319.3 200.8 126.3 79.40 49.95 31.41 19.76 12.43