I'm starting to delve into the 12v
systems for my 28ft 68 Ambassador. I'm planning the wire runs and circuits.
One thing that has me severely confused is that there seems to be some disagreement, or different standards on how to correctly size the length of a circuit. My friend who has just finished a beautiful Argosy build, rebuilt his entire system, and also has a lot of electrical engineering in his background tells me to measure the wire run by the load wire only for calculations.
His advise completely negates the info I've come across on these helpful websites such as this website for van builds
in which they ask for the total run of the positive and negative for calculations. When I calculate by that standard then most of my wire run lengths become incredibly long. For instance, my circuit for the lights in the back bedroom measured from the fuse box up front is at least a 40 foot run when you consider the length it takes to run up the wall and down to the light switch. I have 5 LEDs on that circuit and the draw would be around 1.75 amps max. With their calculator my wire run is 80feet and its telling me I need to run 10awg wire. Ive never herd of anybody running that heavy of a gage wire to a few leds. Seems off?
Do you think these van people double their wire length as a safety standard? I guess you could get away with it in a sprinter, those wire runs aren't too long. It's like this with most online wire gage calculators because most are from van build blogs.