Installing lights on concrete columns can be a challenging task if you have no experience in wiring electrical materials inside or outside your home. If instructions and safety guidelines are followed, you can put in a light on any concrete column or structure, before or after the column is built.
Turn off the main circuit breaker to the power in your home before working on power lines. Injury or death could result if you fail to shut off the power. If you are working in the dark, use battery operated lights to illuminate your work area. Use a neon tester to ensure that the wires don't have power before you touch them.
Tap an outdoor rated electrical power cable into existing power outlets. The easiest place to connect to a power source is an outdoor outlet. Most homes have at least one. The alternative is to drill a hole through your basement wall and extend a line from an inside power outlet. You should consider hiring an electrical contractor if you need to tap into an inside power source for outdoor lighting.
Plan the path of where the conduit will travel from the house to the column. Call the local utility companies to ensure the path does not hit any underground gas lines, electrical cables or water lines. If you tapped into an outdoor outlet, the line should go straight down into the ground and then across towards the column using the shortest route possible.
Dig a trench for your underground conduit or cable. The cable depth can be 12 inches below ground level but your local government will also have local building codes you can go by. Dig the trench by hand using pick axe, mattox or shovel. You can save time by using a machine for digging small shallow trenches. Power tools include chain trencher, blade trencher, excavators and turf cutters. A simple gas edge trimmer may also be adequate for this type of project.
Cut conduits with the appropriate cutting tools. Metal and plastic types will require a saw. Connecting these conduit pieces will take more time to install if there are many turns on the path going from the house power outlet to the concrete column. Use a wire cutter to cut cables to the appropriate lengths.
Lay the cable into the ground if you are not using conduit. If you put down cable without the protection of a conduit, it may need to go deeper into the ground. Typical depths are 12 inches or so. Outdoor conduits come in a variety of materials and rigidity. Popular materials include PVC and steel. Types that are rigid protect the cable inside better and can go into the ground at about six inches. Rigid conduits will require connectors for sections of different lengths and angles.
Lay conduits first into the ground without the cable. Feed the cable into the conduits after the pieces of your conduit system have been determined. As you join each conduit section and joint, pull more cable out, fed from the opposite end.
Install the conduit with the cable into the concrete tube or concrete form before pouring cement for the column. Ensure there is enough slack so that you can connect light fixtures, receptacles or other electrical hardware from the end of the conduit. From the base of the column, connect a vertical conduit from the conduit in the ground. Cover the end of the exposed conduit to prevent it from touching wet cement. Once your conduit is in place, you can pour the cement into the concrete form.
Mount a conduit on the surface if the concrete column already exists. You can use conduit straps and concrete screws to secure it to a concrete, brick or masonry surface. A hammer drill is used to make a hole for the concrete screws. If you don't like to see the exposed conduit, you can be creative and hide it. You can cover it with a façade of any material such as wood, solid concrete, concrete blocks, brick or stone.
Test the fit of the waterproof light fixture on the concrete column opening. This opening should have the end of the exposed conduit. If the fixture is too small, remove concrete using a chisel and a hammer. If the opening is too big, apply more concrete or use spacers to make the fixture fit tight.
Connect the light fixture at the end of the conduit. Take the cable from the conduit and use the cable ripper to open the sheathing at the end of the cable. This will expose the white, black and ground wire. Use a wire stripper to remove the insulation of the metal wire. Take the wires you want to connect and twist them together by color. Secure them by screwing in a wire nut. Be sure that the main power is off and the color of the mating wires match. Add the light bulb to the fixture.
Test the light by turning on the main power to the house. If it doesn't work, test the light bulb and then check all the connections from the house to the light fixture on the concrete column.