Garage Home

Electric

December 24. I have done a little electrical work adding outlets and switches in the house, so I have some experience with wiring. Now I get to do a whole building. Don't try this at home or in the garage! A few milliamps in the wrong place will kill you. I need several circuits for a building this size. I chose a 12 space service panel that uses 2 spaces for the main 100 amp breakers. That leaves 10 spaces. At least 2 will be used for a 220 volt circuit, for table saw and auto lift. Most of the others will be 15 amp circuits. I will have one 20 amp circuit for tools that draw a higher current or I will leave some spaces open for possible expansion. I can use double breakers to conserve space in the service panel. Here is the panel mounted in the wall:

I have already hung two fluorescent shop lights upstairs lit with an extension cord from the house. I took this picture on December 26 after working on the high lift garage door:

December 29. I started a 15 amp circuit today. This is the safest way to do wiring, with no main power cables attached to the service panel! The cable goes through 5/8" holes in the studs, drilled with a hex shank spade bit. The holes must be at least 1.25" from the edge of the stud so wall nails won't pierce the cable:

The blue plastic outlet boxes are equipped with two nails set at an angle. They are easy to line up and nail to the studs. I mounted the boxes 42" above the floor so they will be higher than work benches or work carts. To wire up a box, I punched out a tab in the back of the box and pulled the wires through. There are two sets of wires, one from the panel and one that will go to the next outlet. I stripped about a 1/2" of insulation from the black and white wires. I cut a 5" piece of bare wire and connected it to the two ground wires using a yellow wire nut:

I curved the ends of the wires with pliers so they will fit snugly over the screw terminals on the outlet:

The white wires go to the silver screws, the black wires go to the brass screws and the bare wire goes to the green screw:

I pushed the outlet and wires into the box and screwed it in ( I rotated the one in the picture above so that the ground pin is down). Here are the first four outlets. These are about 4 feet apart so I will always have outlets handy. My trusty stool has become a table to hold all the electric stuff:

January 6, 2008. I have almost finished the first lighting circuit. Two fluorescent fixtures hang high over the first auto bay. A wall switch will turn them on. I will hang fluorescent lights above future workbenches that will plug into the high outlets near the tops of the windows:

January 13. The lift is almost ready for power, so I need electricity more than ever. The feed wires for the sub panel must be enclosed in a conduit from the service panel in the house to the panel in the garage. I will drill a 1 7/8" hole in the wall for the conduit, it's outer diameter. You can see where I have started drilling with a big forstner bit below the panel. The blue plastic ring is a cap ring for the conduit where it goes into the box:

Here is the conduit dry fitted. I will not glue anything until I am sure I can get the big cables through the pipe:

January 19. Here are two of four 100-foot spools of aluminum wire destined to carry current to the garage from the house. Three of the spools are #2 aluminum, for the two hot wires and the neutral wire, one of the spools is #4 aluminum for the ground. I taped the ends of the #2 spools with different kinds of tape so I will be able to identify them later when I attach them to the panels:

With my son's help, the spools were unrolled and taped to keep the wire bundled together:

We staggered the four wires, then taped a spiraled piece of rope to the bundle:

We pulled the 100-foot rope through the conduit using the piece of wire that I had pulled though when I buried the conduit last May:

I used pull grease to lubricate the cable as it went into the conduit:

It looks like some kind of goo from a sci-fi movie:

Here is the cable coming out the other end. It was hard to pull near the end, so much so that the rope pulled out of the tape. I cut the pipe with a hacksaw to get a hold of the end:

Pulled through:

Back at the garage, I measured and cut pieces of PVC to guide the cable into the garage:

All glued together:

January 25-26. I drilled a hole in the house as far as I could go with a 2" hole saw, then finished the hole with a 1 7/8" forstner bit. This made for a snug fit for the PVC conduit:

Here is the conduit, fitted and glued. A bead of gray electrician's putty seals the opening where the conduit enters the house:

Back in the garage, I pulled the four wires through and up to the panel:

Here is a close up of the panel with the four big aluminum wires attached. Two #2 wires go to the main breakers, one #2 goes to an isolated neutral bus on the bottom, and the #4 goes to the ground bus on the right. The stripped ends of these aluminum wires were wire-brushed with antioxidant compound before they were secured. The ground bus has to be clamped to a rod in the ground. You can see the thick bare copper wire coming from the ground bus at the bottom of the panel:

Here is the 5/8" diameter 8-foot copper-clad ground rod before it was tapped into the ground:

The bare wire is clamped to the rod using a 5/8" clamp designated for direct burial:

January 28. In the house basement, the conduit snakes to the main panel. It's all wired up, hots to a 60-amp breaker, ground and neutral wires to the ground/neutral bus in the main panel. The lights are on in the garage! What a great feeling to flip on the light switch for the first time. Electricity through a pipe, like water!

February 2. More wiring. I put ground fault circuit interrupt outlets as the first outlets in the 20 amp lines as per code. These outlets will serve to protect all outlets in the chain.

I installed a compact fluorescent courtesy light and switch by the first garage door.

February 9. Lighting circuits and all 15 and 20-amp circuits are done. One more 30-amp circuit to go:

February 12. I finished all the electric: two 15-amp lighting circuits, two 15-amp outlet circuits for bench tops, three 20-amp outlet circuits for higher current devices like heater and dust collector, and two 30-amp circuits for lift and compressor. Two of the 20-amp circuits end at ceiling-mounted outlets above the garage doors, for future garage door openers. Here is the finished panel:

February 13. Rough electric inspection approved!