What kind of extension cord can you bury underground?
What kind of extension cord can you bury underground?
At 18 inches, you can use THWN-2 conductors inside a continuous length of PVC conduit, which protects the wire all the way through the trench to the house. At 24 inches you can bury underground feeder cable, using PVC conduit to 18 inches below ground only where the wire comes up.