Okay. House wiring uses 10ga for 30a, 12ga for 20a and 14ga for 15a circuits. I didn't look closely enough.
Electricity works is the same regardless of what you do with it. Safe capacity is all about how well the environment allows cooling of the wiring.
Good point. That is why NFPA79 is a good practical tool that errs on the conservative side. The spec is for wire in a raceway or in a cable, which means it is a good guide for our bikes as well, which tend to have tightly bundled wiring in an enclosed environment.
Heavier wiring means less resistance which means less heat.
Absolutely, but that is a different thing altogether. Fusing is to protect wiring. Lower resistance and voltage drop deal more with design intent and maximizing power transfer. One thing often overlooked is connection resistance, which can be a killer. I have been working with a circuit lately in which the connection resistance was more than the wire resistance! Needless to say, when you put 40 amps through it, the connections get quite warm.
Bundling, running in conduit, or running in walls packed with insulation all reduce the ability of the wire to radiate heat away. Maybe the most valuable part of that site is the calculator that indicates voltage drop by size and length.
I would agree. There are many standards out there dealing with this type of thing. In the controls environment I work in, we use NFPA79 and the NEC for our standards. NFPA79 tends to deal more with panel and controls wiring, NEC more with power and building wiring. How and what standard you apply to your application is up to you, and what your end-user needs. I just offered up NFPA79, as it is a good spec that is applicable to determining fusing values. You can't go wrong with it in this case.
