Loved your thread on sizing fuses.
On a recent upgrade, it was necessary to directly connect the alternator (120A) to the house bank. Originally, the alt pos was to the nearby starter and the neg to the engine block. I replaced the small pos wire with a 4AWG of 10' to the house bank. The alt ground was a small, maybe 8AWG to the engine of 1'. Now I know about the ampacity issue and using the total circuit length in sizing cable; but, the 1' length of the neg cable doesn't seem to require the same cable size as the pos. My alt will run at 80A limited, so 80A for 1' doesn't require a 4AWG cable, yet the wisdom is to size the whole run the same. What am I missing here?
On a recent upgrade, it was necessary to directly connect the alternator (120A) to the house bank. Originally, the alt pos was to the nearby starter and the neg to the engine block. I replaced the small pos wire with a 4AWG of 10' to the house bank. The alt ground was a small, maybe 8AWG to the engine of 1'. Now I know about the ampacity issue and using the total circuit length in sizing cable; but, the 1' length of the neg cable doesn't seem to require the same cable size as the pos. My alt will run at 80A limited, so 80A for 1' doesn't require a 4AWG cable, yet the wisdom is to size the whole run the same. What am I missing here?