Digging a trench

Before we could install the wind turbine, my husband had to dig a trench from the wind generator tower to the house for the electric cable. Again, he used his CAD digger. The tower is 250 feet from the house. The trench was three feet deep. After the trench was dug, he and our friend Paul pulled three strands of RW 90 #3 AWG copper wire through 1.25 inch conduit. Three strands were needed because the wind powered generator is three phase. One end of the wire went into the house and was connected to the wind controller. The other end would go up the tower to the wind generator. After the wire was pulled through the conduit, the trench was backfilled.