What gauge wire?
I'm going to be adding a second solar panel and need to know what gauge wire I need for 2/140w panels on a 35' run. Thanks Keith
Forum Discussion
What's your rational for that conclusion? Where's the analysis? My hunch, it's not pretty.
Hell, let's do it right now.
10 awg wire resistance = 1.0 mohm/ft
We got 70 ft of wire.
Total wire resistance = 70 ft * 1.0 mohm/ft = 70 mohm
2 x 140W panels outputs about 2 * 8.7A = 17.4A.
Wire loss:
V = I * R = 17.4A * 70 mohm = 1.2V
P = I^2 * R = 17.4A^2 * 70 mohm = 21.2W
The cable causes a 1.2V drop and consumes 21.2W, or about 7.6% of 280W.
Hell, let's do it right now.
10 awg wire resistance = 1.0 mohm/ft
We got 70 ft of wire.
Total wire resistance = 70 ft * 1.0 mohm/ft = 70 mohm
2 x 140W panels outputs about 2 * 8.7A = 17.4A.
Wire loss:
V = I * R = 17.4A * 70 mohm = 1.2V
P = I^2 * R = 17.4A^2 * 70 mohm = 21.2W
The cable causes a 1.2V drop and consumes 21.2W, or about 7.6% of 280W.
pianotuna wrote:
Hi,
#10 will be just fine with a pwm controller.
