It's tough to speak freely with people who possess the knowledge that is required without them asking- What is this for?? Here's my question: I will be running three lights, perhaps a fourth- but three for now. They are 1000 watt HPS, they draw 4.75 amps at 240. I want to run them off a 50AMP dryer plug that is located downstairs, about a 55 foot run. Is 10ga wire enough, or should I use 8? 10ga is rated 30Amp from what I can find out, which should be plenty, but I'm concerned that I may be right on the line, so to speak. Would 8guage be complete overkill? Normally, I would just buy the better stuff, but 8gauge is harder to get and costs a lot more money. Anyone who is qualified that can give me a straight answer would be most appreciated!! Thanks!
You are correct. 30 amps for a 10ga run. I wouldn't see any reason to run 8. You could run 5 of those ballasts and still be just under 80% load.
10 will cover you beautifully. If you're planning on upgrading a whole lot in the future maybe run the 8, but for what youre doing now you'll only be at like half rating.
run the 8. It will be safer, and you will always have room to upgrade on anything in that room. When wiring my home or garage, where code calls for 14ga i run 12.
Hey I forgot to chime in and say thanks, you guys. As it turned out, it was cheaper to buy a precut 125ft roll of the 8 than it was to get 60 ft. of 10 off the spool at Home Depot. I went with the 8, of course. I feel better about it too. Thanks!