Installing Outdoor Electrical Wiring

Cable

Use UF cable when running cable outside the home. UF stands for "underground feeder", and the "UF" is clearly marked on the cable sheathing. Bury the cable at least 2 feet underground. If the cable runs above ground, it must be in conduit to protect it from possible damage.

Exiting the House

Install a junction box inside the house at the point where you want the cable to exit. Make your connection between the internal and external wiring in that box. Put a conduit nipple in the hole to the outside and run the cable through that. If the cable is exiting the house above grade, you need to connect the nipple to an L-shaped connector called an LB conduit fitting. The LB conduit fitting has a removable cover on the back that allows you to access your cable connection. There are also LL and LR fittings, which have covers on the left and right, respectively. The cable should exit the house at least 12 inches and no more than 78 inches from grade.

Receptacles

You must have at least two outside GFCI-protected receptacles in your home, one in the front and one in the back. Keep the receptacles within 78 inches of grade. You can mount them flush with the wall or recessed. Boxes that are mounted flush must be rated for outdoor use, whereas recessed boxes can be of any type. All receptacles must have watertight-while-in-use lids if you plan to leave them unattended while in use. For example, if you hang Christmas lights outside your house, you must have a watertight lid on the box. For the most effective and aesthetically pleasing installation, recess all your outlets into the house siding .

Lights

You must have switch-operated exterior lights outside all entrances of your home. If you have a separate garage with power, it also needs lights outside the entrances. Parabolic aluminized reflector (PAR) lamps are the best type of lights to use outside. Outdoor lights come with gaskets that are supposed to help the lamp stay waterproof. Unfortunately, the gaskets tend to move around during installation, which can result in bad seals. Use some hot glue on the gasket when installing the light to prevent the gasket from moving out of place.