300ft run for power to shed?

[HayZee518]

if you are going to run 10/3, stick to 10/3 inside the house. don't go splicing 8/3 onto it. somewhere down the line the next guy's gonna see a double pole 30 breaker onthe 8/3 and may increase it to a double pole 40. in this case you'll be jeperodizing the 10/3

[crabjoe]

Here's another idea. with the 10/3, I won't have a sub panel at the shed. So now I'm thinking adding a sub panel on the other end of my house where the line to the shed will be. It would make things easier too because that's the side of my home where my current workshop is in the basement and I always need to put an outlet or what not in. In fact, I have to run a line for a water softener, so having a sub panel there would make it easier.

[HayZee518]

about the only reason you would have to put in a sub-panel is to make the "home runs" "shorter." or the need for more circuits than the 40 circuits in a main 200 amp (or higher) panel. I had wired a house in massachusetts that was 80 feet long and 50 feet wide. the main panel was in one corner of the basement. what that means is each home run back to the panel would have to be 80 plus feet. so the kitchen had a sub panel, the garage had a sub panel and the out-building had a sub-panel. any sub-panel feed is a four wire - isolated neutral and an auxillary ground bar inside. you could use a sub in your location with a #8/4 romex feeding it. would be protected by a double pole 40 breaker.