Can a wire gauge be too large?

pishta said
Extension cords are prime examples of "do your homework" I have a Craftsman air compressor that has a 4 foot power plug, useless. So I haul out my 50 foot green cheepo extension cord and fire it up, well it sounded like a Volkswagon starting with a dead battery..wump-wump-wump-fzzzzz! Blew a 20A circuit breaker in my panel, garage went dark. Then I tried the heavier orange one I have. That worked decent but the compressor never did build pressure and the wire got physically hot. Nix on the extension cords!Maybe I should have read the manual? I then bought 20 feet of stiff 12/2 Romex and wired up a plug on one end and a plastic J-box on the other and installed a receptacle. Now that baby kicks over like it was plugged straight into the wall.

That's because you used the proper guage/length of wire. I'm sure the manual would have listed the appropriate guage of extension cord to use for a given length of cord. A good quality 12ga./20' extension cord capable of carrying 20A would have worked just as well. But those aren't cheap...so most people just use the 16ga. 50' ones they get at harbor freight and wonder what's wrong with my compressor or what ever they are trying to run :banghead:
Lots of lessons here...at least you corrected the problem with running the same wire you would have run in to extend a 20A circuit...so in essence it is plugged into a wall. All the information (voltage/amperage/) is printed on every motor or electrical device made today. If not sure what all those number mean...find out before you connect it.