I built a Shed 30 x 20 . The location is at approximately 150 to 180 feet away from the main building electric box. I will have three switches, three outlets and 4 fluorescents (each with 4 bulbs) light fixture, with a #14 wire. Beside I will have three outlets for a work shop by the counter top table with #12 wire. I Am planing to run an AC floor unit while I am working there. Maybe I will install a vacuum system while I do cuttings. It will be OK if I set a 3/4" gray pipe to run two circuits #14 and #12 wires on a two separate breakers with 15 and 20 amps? Or I can run #8 wire on a 40 amps breaker to a sub-panel in the shed and two or three brakers (15amp, 20 amps) in sub-panel? Please help with some answers it will be appreciated it. Thanks. JJ

Due to the size of the shed and the potential to have some decent motor loads, and the distacne, I would install #2 - 4 wire aluminum URD cable, which can be direct buried, to eliminate voltage drop.

You may sleeve the URD cable with 2 inch PVC conduit for added protection if the soil is rocky, and will allow the cable to be replaced or upgraded later with no excavating.

Your plan of running only # 14 and/or #12 that distance will not work at all.

Without knowing exactly amp or wattage load of the motors, I suspect #8 copper will not be sufficient either.

Aluminum wire is much cheaper than copper, and when sized and terminated properly, works just as well as copper.