Chassis Wiring Vs. Power Transmission

[jpfabricator]

Can one of you electrocuioner clear up some confusion I have on wiring some 3pz? I scored a roll of 8ga copper stranded wire to power up my lathe. It's required amperage is 20.
One of the charts I have has two different number ratings for my wire "Maximum amps for chassis wiring" and " Maximum amps for
power transmission"
What is the difference in these two "ratings" as there's about a 50amp gap?

Sent from somwhere in east Texas by Jake!

 

[Eddyde]

Chassis wiring is shorter runs thus can handle more amps. Transmission runs are generally longer so more resistance, less amperage capacity.

 

[JimDawson]

I had to do a little research on that one, I found this:
http://www.netcrafting.com/car_mx/cadillac/CadillacRadioandSubwooferInstallationNotes.htm
Look about halfway down the page. It looks like that chart applies to automotive, rather than stationary wiring.

#8 THHN is normally rated for 50 amps per NEC on normal length runs. You'll be fine at 20 amps.