Power distribution in basement shop

[Julie Moriarty]

Lighting circuit is run. DC circuit is a single outlet home run.

One thing I failed to elaborate on is that since it is a basement shop, the power feeds are all over head (due to door ways, concrete walls, and slab floor). The idea of running up and down each wall seems like it would take a whole bunch of extra wire. As Phil mentioned, I was thinking of doing a trunk line-drop line design with boxes at the ceiling line dropping to the outlets. Unless someone knows of a better way.

Why not run conduit from box to box on the walls? If you don't want to mess with conduit, then yes, place an occasional junction box on the ceiling to minimize how many cables run into a given box, and drop down from those. You shouldn't be running more than 4-5 cables into a standard 1900 box anyway. Most municipal codes around here don't allow more than (4) conduits in a 1900, (5) in a deep 1900 and (6) in an 11-B box. (There are also rules regarding the size of the conduits but no need to get into that here.)

You definitely don't want to stuff the box with wires. It introduces problems like shorts and overheating. Distributing junction boxes along the ceiling (if you don't run conduit on the walls) reduces the amount of cables entering a box and makes terminations easier, as well as tracing out problems later. If you keep the number of cables entering a given junction box to 4-5, your life will be easier.

[Anthony Whitesell]

Why not run conduit from box to box on the walls? If you don't want to mess with conduit, then yes, place an occasional junction box on the ceiling to minimize how many cables run into a given box, and drop down from those. You shouldn't be running more than 4-5 cables into a standard 1900 box anyway. Most municipal codes around here don't allow more than (4) conduits in a 1900, (5) in a deep 1900 and (6) in an 11-B box. (There are also rules regarding the size of the conduits but no need to get into that here.)

You definitely don't want to stuff the box with wires. It introduces problems like shorts and overheating. Distributing junction boxes along the ceiling (if you don't run conduit on the walls) reduces the amount of cables entering a box and makes terminations easier, as well as tracing out problems later. If you keep the number of cables entering a given junction box to 4-5, your life will be easier.

Definitely running the 220 and the 120 circuits separately. For each circuit a box would have two wires entering for the trunk line (one in, one out) plus two more for the outlets (one on the north wall one on the south). So a total of 4 wires per box likely entering from three to four different sides. The trunk line runs the 20 ft north wall, to traverse from the box above the north wall to the box in the south wall would include a 12' run from north to south. Horizontal conduit runs would reduce the length of wire to be pulled, but at the expense of buying more steel parts to save on copper, it may be a wash. Another option I considered was splitting the trunk line the run at the first box and running a set of boxes above the north wall and another above the south wall. But I was thought that plan would add expense and extra connections that just were not necessary. I was wondering if someone knew of a cheaper or more efficient plan, but it appears I may already have.

It is not just a wiring renovation but also a wall renovation so I will have access to the boxes behind the sheetrock. No need for surface wiring. I have come to the realization that I am trying to fit a 6ft wide tablesaw into a 12ft wide space that will need 16ft of the 20ft available to rip an 8ft board. Every inch is becoming more valuable. While I'm thinking about it, what is the minimum depth box available and allowed for a standard single duplex outlet? Maybe I can make the new wall studs thinner (2x3 or 4x2) and pick up a couple of inches.

[Julie Moriarty]

While I'm thinking about it, what is the minimum depth box available and allowed for a standard single duplex outlet? Maybe I can make the new wall studs thinner (2x3 or 4x2) and pick up a couple of inches.

A standard 1900 box is 1-1/2" in depth. A deep 1900 is 2-1/8" deep. Either would fit in your 2x3 stud wall. What I did was shoot 2x2s to the foundation wall and insert 1-1/2" foam board in between the studs. Then I covered that with standard plywood paneling - no drywall. The foam board gives the paneling backing in between the studs and feels just as solid as if it was mounted on drywall. All the boxes on the foundation walls are standard 1900 boxes.