Outlets in shop floor

[Bob Cooper]

I'm building a new shop. It will have a basement under it so I have the oppty to run dust collection and some electrical under foot. So what's the best way to put outlets in the floor?

I was thinking of actually having small covers that the cords went through and attaching electrical boxes to the joists beneath but I'm just starting to think about this

[Danny Hamsley]

That sounds good. My floor is 3/4" treated plywood with a crawl space underneath. I just mounted the boxes on a joist and put the cover flush on top of the floor. The one thing that I have found is the importance of thinking through how you will organize your equipment and where the outlets need to be.

[Jerome Hanby]

I think the traditional method is those little lumps that stand up on the floor. They always looked tailor made to trip me. I like your notion much better.

[Joe A Faulkner]

In my area, Home Depot carries a very nice sturdy recessed floor outlet with a brass cover. If it were me, that is what I'd use. The box is extra thick to withstand having tools rolled over the outlet. The boxes are not cheap, but it is a one-time expense and you probably only need two or three outlets actually mounted in the floor. These outlets are designed to meet code. What your are proposing sounds creative, unconventional, and probably a code violation. Maybe an electrician can comment on the code issue.

http://www.lalightingstore.com/products/Lew-Electric-Recessed-Floor-Plate-Assembly-%28Duplex-Receptacle-with-Box%29.html

[Bob Cooper]

My concern with the nice brass ones are (1) cost and (2) sawdust getting into them

[Scott T Smith]

My concern with the nice brass ones are (1) cost and (2) sawdust getting into them

+1 re the sawdust. Whatever you come up with, it would be a good idea if it was either sawdust resistant or installed in such a way that sawdust would not fall directly into the receptacles.

[Rollie Meyers]

You cannot cobble together something & use it for a floor box, it must be listed for the purpose.

[Ken Garlock]

Good morning, Bob.

I have in floor trench for dust collection for my major tools, planer, table saw, router, and jointer. In the same trench, I have a single run of 240v 30 amp, 10 ga. wire. Each of the tools is located such that it straddles the trench. Each tool is connected to that single line via a junction box and a twist-lock plug. The wiring exists in the trench along with the 6" PVC dust collector plumbing. BTW, the trench is covered by multiple sections of 1/8" diamond plate steel.

In your situation, I would not consider any type of traditional outlets mounted in the floor. I would run the wiring along with the dust collection piping with the twist-lock near the mag switch on the tool. I assume ;you are using this for major tools that use a magnetic off-on switch.

[Jonathan Spool]

I like the covered floor trench idea. In one of my earlier shops I installed floor outlets, but consistantly had sawdust issues with them. If the outlets were permanently dedicated to a specific use, and the plug not to be removed, perhaps they would be a more reasonable option.

[Von Bickley]

Bob,

I only have one floor outlet and it's not in the floor. I have a pipe flange mounted to the floor with a 18" piece of galvanized pipe for the riser, with my electrical box mounted on that. It is next to my outfeed table so it is out of the way. It also provides an outlet to power receptacles mounted on both sides of the outfeed table.

It is 18" above the floor in the vertical position so I don't have to worry about sawdust collecting in it. You could install one next to your table saw, outfeed table or work bench.

[Alan Schaffter]

The DC ports for my TS and jointer are in the floor of my second story, above-garage, shop and are covered with hinged lids when not in use. The blast gates which I converted to autogates are in the garage below, near the ceiling where the ducting runs, and no longer on the machines as in these old pics.

I also put an electrical box in a recess in the floor. It has two pigtails with female cord-type receptacles. I used cord receptacles and pigtails to avoid dust getting into a duplex receptacle. I made the recessed box large enough to hold excess cord. I cut a notch in the hinged lid for the cords.

http://www.ncwoodworker.net/pp/data/500/medium/Odc-4.JPG

http://www.ncwoodworker.net/pp/data/500/medium/P5260045.JPG

http://www.ncwoodworker.net/pp/data/1329/medium/P1010091a1.JPG

[Bob Cooper]

Alan:

what you're showing is what i had in mind. i really like how you handle both the cords and the dust collection. It's unclear how you got your cords through the small holes though. I wish you were closer as i can think it 10 questions. Can you get to your electrical outlets from the garage? what is your floor material?

[Alan Schaffter]

Alan:

what you're showing is what i had in mind. i really like how you handle both the cords and the dust collection.
It's unclear how you got your cords through the small holes though.

The cords don't go through a hole, I notched the edge of the hinged rectangular cover. It is a little easier to see in this pic:

http://www.ncwoodworker.net/pp/data/500/medium/P5220034.JPG


I wish you were closer as i can think it 10 questions. Can you get to your electrical outlets from the garage?

No, I didn't make the outlets accessible from the garage. No need. I opened the end of one garage ceiling joist bay in the utility room which is just below my shop breaker box. I snaked Romex from there between the joists and while to kosher, let it lay loose on (under?) the insulation. I had to cut two access holes in the garage ceiling drywall on either side of a large microlam cross beam visible in my earlier pic, so I could drill a hole for the Romex to get the joist bay on the other side. The outlet box is a few feet past the beam. I made the cord storage/outlet box from pieces of ply and attached it to the joists. If you are interested I can take a photo of the ply box, electrical junction box, and the two pigtails.


What is your floor material?

Advantech subflooring (http://www.advantechperforms.com/product-lineup/advantech-flooring.aspx) . It is like OSB but much smoother, tougher, denser, more rigid, and waterproof. It is available at Lowes and everywhere. I painted it with a urethane modified enamel porch and deck paint- bad decision- too slippery. I will eventually put down oak.

[Josh Bowman]

I spent a long time battling with myself over how I wanted these in my shop. I finally opted for an easy way, so the concrete finishers couldn't mess them up. I ran plastic 3/4 conduit to metal sweeps and drove unistrut in the ground and strapped the sweeps to the unistrut, all of this got 4 to 5" of concrete poured over them. It took a lot of planning to get the machine placement right, but even at that they worked fine. Wish I had ran a couple of more. The 3/4" gave me plenty of room to pull more wire after I upgraded 2 of my machines to 220 volt. I cheated a little there and borrowed 110 volt off of one of the 220 volt legs so each of these outlets have a 220 box and 110 box. The outlets are very strong and will not move......but if a machine is not near them, they could be a trip hazard. I also created a "chicken foot" with 4" PVC drain pipe that wye's down to one pipe going to my dust collector. This also has worked well. Good luck.

[Bob Cooper]

Thanks all. On the flooring... I have the Advantec flooring down and am debating covering it with another material primarily for looks but I should start another thread on that else it'll get buried.

Is the PVC pipe you're showing 4", 5", or 6"? Any regrets going with PVC?

[Alan Schaffter]

Thanks all. On the flooring... I have the Advantec flooring down and am debating covering it with another material primarily for looks but I should start another thread on that else it'll get buried.

Is the PVC pipe you're showing 4", 5", or 6"? Any regrets going with PVC?

I used 6" thin wall PVC known by various names- "Sewer & Drain", "S&D", "solid perf", ASTM 2729. It is not the thicker-walled and heavier SDR35 (but has the same OD) and is not the more expensive and much heavier standard Sched 40 DWV pipe which has a different OD. (note- pipe prices are close, but Sched 40 fittings are outrageously priced). ASTM 2729 is available at homecenters in 4" but you will need to go to an irrigation or landscaping supplier to get it in 6". There are plenty of threads here about that.

No regrets, I would use it again over metal.

[Josh Bowman]

Thanks all. On the flooring... I have the Advantec flooring down and am debating covering it with another material primarily for looks but I should start another thread on that else it'll get buried.

Is the PVC pipe you're showing 4", 5", or 6"? Any regrets going with PVC?
I used 4" sewer pipe (thin wall stuff) Sometimes I wish I had used 6", but really have had no problems. I did do something kind of unique. I broke down my Grizzly 2hp dust collector to just the blower and mounted it in my attic of the shop. I now discharge the dust and chips into a garden cart that's pulled up to the outside of my shop. The increase in flow is remarkable and the noise level in the shop has reduced to almost a hum. Now even running my planer or sucking up large piles of turning shavings, the pipes don't clog and my shop is much clearner with not trying to recirc the dirty air. Even though my shop is tight, there is enough gaps that easily make up for the discharge. For my purposes this was the best upgrade I ever did and with most everything under the slab, my ceiling height is not challenged.

[Tom Ewell]

Bob,

I only have one floor outlet and it's not in the floor....
It is 18" above the floor in the vertical position so I don't have to worry about sawdust collecting in it. You could install one next to your table saw, outfeed table or work bench.

Did similar in my shop, located several quad outlet (mostly dual-20a) "pedestals" at work stations around the floor. None of my stuff is hardwired and all is mobile, it also allows for a quick unplug for servicing.

Can also have DC switch pedestals (a little taller) at a few locations.