Difference between maximum amps for chassis wiring and power transmission
Chassis wiring assumes each wire is routed separately, and power wiring assumes they are wired in a bundle. In chassis wiring the cooling of the conductors is better, because they are all exposed directly to air. In a bundle, some of the wires are not in direct contact withe the air.This is why maximum current for chassis wiring will be more compared to an equivalent power transmission.