I have a new 1500 sqft pole barn that needs electric. I expect to need 100Amp service at the barn which will have a 220V 15A compressor and 220V 25A welder. The rest of the barn will be 110V fluorescent lights, and few if any high amperage tools. My house has 200A service, and I could branch off a 100A breaker from the house breaker box.
My first question is: Can I run 275 ft of underground feeder wire (in pvc, 24 inch burial) to this barn from a 100A breaker at the house? I've done some calculations that suggest #1 aluminum feeders would be good, and the voltage drop should be less than ~3%. But most calculators stop at 250ft, and runs over 250 ft aren't discussed much. I want to ask here because the experience is unmatched. The house has a good 3-wire feed and breaker box. But the house is all electric. I'm willing to go with copper feeders if I have to.
I plan to use two 8ft deep copper grounds at the barn.
I done a lot of research and can't find a definite answer on maximum feeder lengths. BTW our state uses the 2014 NEC codes, but I'm all about safety.
EDIT: Thanks again, let me give this a try. I'll probably not be using all tools or equipment at once. Figure VERY intermittent use of the compressor and welder because I'm not setting up a paint booth. But a 50A car charger is a real future possibility (thanks @jwh20). A large fan, permanently wired (but not always on) could be 8A (so figure 10A), a heater or small A/C (for a very small office) would be about the same 10A because it will be on when I'm in the barn when the compressor kicks in. Lighting would be LED almost certainly just as in my house with no weed being grown. So 1500 sq ft of space needs requires three 20A circuits for lighting, but will likely be less than 5A. Add an extra 10A for everything else, so my provisioning is for 50+10+10+5+10 or ~85A (someday).
Wire type: Using UG-F inside conduit seemed to be the safest, most long lasting option. Because THHN/THWN saves more space within the conduit (thanks to @NoSparksPlease) this decision will likely come down to availability and costs. Thanks also to @Ecnerwal for the tip about putting the grounding rods in the trench, and that 18" deep is enough. I'm not crossing any roads or areas where there will be vehicles crossing.
The ampicity table 310.15(B)(16) under 60C says that at 85A I'm at AWG3, or at 105A I'm at AWG1. So if I use AWG1, I can use a 100A breaker. the ground wire would need to be about #8 (Best guess). But now I need to check the voltage drop.
So you guys are magic or something, because I went to the voltage drop calculator that @Ecnerwal recommended and it was literally already set up exactly for this. Using 275ft of AWG1 aluminum wire, I would have a 4.48% voltage drop, and would have 229.25V at the barn. This seems okay to me (not in Canada I assume) with the main line only 15 ft from my house meter and breaker box.
I know I need to mark an answer... Hard to pick just one but going with @Harper - Reinstate Monica for the process he described, but you all were extremely helpful.