You will need to prepare a trench to specifications, use
	special wire, protect the wire with conduit or special plastic
	tubing and possibly lumber (don't use creosoted lumber, it rots
	thermoplastic insulation and acts as a catalyst in the corrosion
	of lead).  The transition from in-house to underground wire is
	generally via conduit.  All outdoor boxes must be specifically
	listed for the purpose, and contain the appropriate gaskets,
	fittings, etc.  If the location of the box is subject to immersion
	in water, a more serious style of water-proof box is needed.  And
	of course, don't forget the GFCIs.

	The required depths and other details vary from jurisdiction to
	jurisdiction, so we suggest you consult your inspector about
	your specific situation.

	A hint: buy a roll of bright yellow tape that says "buried power
	line" and bury it a few inches above where the wire has been placed.

Some parts © 2009 Advameg, Inc.