Hey guys,
Just looking for a quick answer to a question: What is the max current that should be run over a 4 guage power wire (16 ft) and what is the largest AGU (cylinder) fuse size that could (should) be used on such a wire. I heard somewhere that the max current should be limited to something like around 130amps, is this right? Thanks,

Fabiano.

*drags out canadian electrical codebook*

4 guage, 75 degree C rated conductor, 125 amps.
however... since it runs through the engine compartment, which can get pretty warm, we have to derate the cable somewhat, I'm using 40 degrees C as an ambient temperature just for the sake of arguement, which gives us a derating factor of .88

so, 125 amps, X .88 = 110 amps.

why did I do this? generally, I find that the codebook is a great guideline for setting fuse/conductor sizes

Good guy to keep around.

I think I'll be looking around for one of those books now.

So basically I suck because I will soon be having 210 amps and a 4 guage that's going to spontaneously combust! Thanks guys, let the inferno begin...

I've done most of my own training by trial and error. I've also made lots of smoke appear from behind my dash when I was growing up. PS: Never use 22awg wire for power wire.

Something I should ask is: What equipment are you using to get 210 amps of draw.

[ June 11, 2004, 08:13 PM: Message edited by: JTerp ]

One of the reasons I like to set up 4ga with AGU fuses is they only come up to 80 amps and ususally you don't see over 60amp ones. It is a good match.

Just curious, the code book is for solid wire right, or does it apply the same way to multistrand wire? It goes by cirular mils, or something along those lines?

it goes by the wire guage, which is based on circular mils, not the physical size. a 1/0 solid wire is physically smaller than a 1/0 19 strand wire, but 1/0 welding cable is in between.

this should help you out

http://www.the12volt.com/info/recwirsz.asp

Thanks guys!