Gauge And Amps!!

[KernF150]

Can anyone tell me how many amps 10 gauge and 8 gauge can handle. I'm going to be adding a fuse box in my cab. i don't know if i should run 8 or 10 gauge.

 

[glamisdude72000]

Good chart here: http://74.50.20.110/wiringdiagram.jpg

Its intended for stereo equipment, but amps are amps. Hope this helps!

 

[summerprophet]

It depends upon the length of the run, and whether you are using AWG or SWG wiring. I did a google search for Maximum wire amperage automotive, and it pulled up a few charts, and went with the most conservative of the charts.

If it helps, I did my fusebox with 8 gauge wire and a run of 4 feet, powering 100 amp box.

EDIT:
Also, consider constant load versus brief load. Obviously lighting circuits are going to be on all the time, but if you are running power to switches, compressors, or temporary used items, I might be OK with exceeding suggested wire gauge. Just make sure you do it with knowledge and intent, not cost savings or convenience.

 

[4x4junkie]

It depends upon the length of the run

This right here.

#8 wiring could handle 100 amps or more for a brief period @ 12V, but unless the wire length is real short, the voltage drop at that current is likely to affect the performance of whatever it is you're powering.

I always shoot for less than a 5% voltage loss (often times less than even 3%), so whatever gauge wiring it takes, that's what I use.

For an item that is located 10 feet from the battery which is expected to consume 30 amps, this would mean using #8 AWG for the power runs (3.6% or so loss) or #6 AWG (2.3% loss).


A good site I found for calculating voltage drop of your wiring:
http://www.nooutage.com/vdrop.htm

 

[Andy@AAV]

If you have a specific brand of wire in mind check the manufacturer web site, they should have a chart showing amps vs run. If they don't show it you might want to try another brand...