How to Wire a Garage
If you just built your garage, or your garage just doesn't have enough lights or outlets, you may want to consider wiring it for electricity. Wiring a garage can be done over a weekend or two if you have the right tools, supplies and some basic electrical knowledge. If you have limited knowledge when it comes to electrical wiring, you may want to leave the installation of the main panel up to an electrician.
You will need:
Tools
- Screwdrivers
- Screw gun and bits
- Electrical tester
- 3/4-inch hole punch
- Conduit tubing cutter
- Ditch digger
Supplies
- 1/0 electrical, three strand wire
- Electrical tape
- Electrical fish tape
- 50- or 100-amp junction box
- 3/4-inch conduit, connectors and elbows
- Main panel junction box
- Knee pads
- Gloves
- Goggles
- Turn off the main electrical power at the breaker box. Be sure to wear protective eyewear and other protective gear. Using a screwdriver or screw gun, remove the cover of the panel. Use an electrical tester to make sure that the power is off.
- Create a 3/4-inch hole in the bottom of the main breaker panel. The breaker box is usually located on the side or the back of a house. Use a conduit connector to connect a 3/4-inch conduit to the bottom of the main panel box. Measure about 18-inches and use a conduit tubing cutter to cut it.
- Drill a 3/4-inch hole through the wall of the garage, directly behind where you plan to place your junction box. You will need to install a small junction box at this point using a conduit connector. Create a 3/4-inch hole in the bottom of the box, just like you did with the main panel box. Use drywall screws to secure the box to the wall.
- Call you local utility companies to make sure that it is safe to dig. You will have to dig a trench to run the electrical conduit from the house to the garage. Use a ditch digger and make a trench that is about two-feet deep and one-and-a-half-feet wide.
- Connect a conduit elbow to the junction box and run it into the trench. Connect another conduit elbow to that.
- Place 3/4-inch conduit in the trench, using connectors to secure each section together. When you reach the garage wall, install a 50-or 100-amp junction box. You should consult an electrician for this step of the installation. Use drywall screws to mount the box to the garage wall and install a 3/4-inch conduit connector to the bottom. Run a section of conduit into the trench and connect it with a 3/4-inch elbow. The conduit should be completely connected now.
- Run fish tape inside the length of conduit, as this will help you pull the wires through. At one end of the conduit, attach electrical tape to a 1/0 wire strand and attach that to the fish tape.
- Use the fish tape to pull the wire to the end of the conduit. Make sure the wire extends at least 3-feet past the junction boxes. Strip the sheathing off the wire and connect the wire to the junction boxes in both the garage and the main panel. Black wires go to the breaker, neutral wires go to the neutral bar and ground wires connect to the ground bar.
- Drill holes into the studs in the walls of the garage and run conduit circuits for both lights and outlets. Also consider any heavy-duty appliances that may need to have their own lines.
- Install plastic boxes for all of the outlets and light switches. Outlets are most often installed about one-foot from the floor and light switches are usually installed about four-feet off the floor.