[/QUOTE=scotzz]I think that quote is from a thread I was involved in last year. I spliced in a standard dryer cord to a 10 gage line I ran into the garage for a welder (20A). The dryer line is on a 30A breaker meaning that the welder (or anything else not rated at 30A on that line) may not be protected. But, this is the same as probably every appliance or power tool you plug into a 120v outlet so to me it's a moot point. In my case, the 10gage line ends in a 20A plug but wire size is correct for the 30A breaker. I got some crap for this setup but I maintain that as long as the wire size is correct for the breaker and workmanship is correct it is safe. I included pictures of my set-up in that post.[/QUOTE]
Again, the circuit breaker or fuse is not to protect the welder or anything else that is hooked up to the wire. The breaker or fuse protects the wire. That is why a circuit is first sized for the anticipated load. Then the circuit breaker is selected as is the proper wire size for the anticipated load. Wire size is selected at 125% of max load.