Electrical for new shop

[lexrex]

I thought I might try to keep this all in one thread but I also thought it might have more visibility separately. Maybe I'll merge them later....

Electrical: In wall or conduit? The only reason I was thinking conduit was the flexibility of being able to add circuits and move large tools to an opposite side of the shop without going into the walls. I think I'd do a couple 110 20 amps in wall to have all around the perimeter but the more specialized circuits largely for 220 in conduit.

Discuss.

[Stretch]

Well, if you run it in the walls, and want to add circuits later, you can always run conduit then. I ran all my wiring in the walls, just because I didn't want the extra expense of buying conduit and connectors or the extra aggravation of pulling wire through the conduit.

[TDHofstetter]

Pull it all in the walls, and pull plenty of it. Copper's cheap - your time ain't as cheap. Ya see... to redo your wiring, you'll've hadda' move all sortsa' stuff away from where you're workin', and after you're done sparkin' stuff you'll hafta' move your equipment back to where it was & such. Takes a lot more time than you might figure.

Copper's cheap. Romex is REALLY cheap.

If you run conduit, ya don't run Romex in it - instead you run individual stranded wire. Romex won't pull worth a DANG.

Pull Romex. Pull plenty of it, enough to do everything you'll likely ever do. Pull it now, pull it once, and pull it inside the walls.

[Leo Voisine]

I run all wiring in the walls

The 110 is all 12 gage for 20 amp

The 220 is all 10 gage for 30 amp., but ya don't need that.

Remember - 220 usually means LESS amps at the machine. You Could have a 15 amp 220 and run 14 gage wire. Even a 20 amp 220 circuit is 12 gage.

Soo - you don't need conduit - unless it is single wires on running outside.

[Beamer]

When I did mine - i ran in-wall. My reasoning was mostly cheapness and appearance. I drywalled and drywall's real easy to patch almost invisibly.

If I didn't wanna bust into the drywall, i could always surface mount with conduit. But I really like not having all that conduit on the walls to have to contend with.

[Beamer]

Oh, i should also point out ... my old shop got rewired 4 times because I cheaped out the first few times and only ran outlets for what i HAD. It became clear to me that I needed to think well beyond reality with wiring.

The current shop - I ran 5 220v circuits (4 20a, 1 30a) and 7 110v circuits. Two separate light circuits in the ceiling (circuits, not switches, so if i blow one, half my lights stay on). I ran 3 110v circuits along the wall, two outside, one to the back wall where the shed was gonna be built and one to my fridge after the fact.

I have 900ft of 12ga romex in my walls/ceiling/attic/floor. I put a 220v outlet every 3rd stud - on 3 different circuits. I put a 110v outlet on every otehr stud. Plus 10 in the ceiling and two in the floor (i laid a wood floor).

Yep, it was a pain. Yep, it cost more than I really wanted to spend. But it wasn't as painful as it would have been to add the circuits after the fact. It would have cost more to surface mount, too. I still have 3 slots left in my sub panel. I'll use 'em, i'm sure, when I build the 2nd shed in back and magically connect them to the shop and build my finishing room. But all that work will be attic work and hidden

[CajunRider]

I wish I could put mine in the wall. All my wiring has to be in conduit because all my shop wall are break away wall. So all my wiring are in conduits attached to the piling. No wiring is allowed in the wall.

[brburns]

One other thing to note about conduit, It will collect dust. I run most mine in the wall. I do have it in conduit going from my phase converter to my jointer and TS, but they are 3 phase and conduit was eaiser/cheaper than any oth way.

[Ruffnek]

When I built my shop, I ran 12 ga. wire inside the walls for 120 vac outlets every 4 feet on four separate circuits. That has worked well.

Since I did not provide enough 240 vac outlets for future tool acquisitions/upgrades, I am now running it inside conduit attached to the walls.

If I had it to do over, I would have also run 10 ga. wire for 240 vac circuits inside the walls and placed outlets every four feet alongside the 120 vac outlets.

The lesson learned...you can't have too many outlets, both 120 and 240 vac. It's better to pull the wire and install the outlets while the walls are open than it is to add them in later, whether inside the walls or inside conduit.

[sawduster]

Conduit also interferes with hanging cabinets and such that you'll want to do in the shop. PITA to notch everything out for getting over/around the conduit.

If you need to add circuits later, cut out access holes near the ceiling. Big holes using a saw to cut out the hole are as easy (or easier) to patch than small holes, so make them plenty big. Also, you'll need access inside those holes to drill though the top plate of the wall so . . . Makes fishin the new wire a breeze.

[jim]

I put all my elect in conduit on the surface of the walls and am glad I did. It can be moved much easier that way and I have learned that nothing is perminant in life. Look at almost all industrial shops, you will see everything mounted to the outside of walls. Elect ,ventalating and piping of all sorts.
Also I suggest you not put in duplex 110V outlets put in fourplex boxes.

[rrich]

I used conduit in my shop also. It was so much easier and should anything change, it's all in the conduit.

When I purchased the wire and conduit it was cheaper to do it that way, not much but still cheaper.

If you keep your phases color coded (Red phase and Black phase) through the conduit, you can get by with a single neutral wire. (Two circuits, one red and one black using the same neutral wire.)

Also you can use a 12 gage (green) ground wire for most circuits and you don't need to 10 gage ground wire and a single ground wire is acceptable for the dual circuit arrangement described above.

The thing that is really important is to use a ground wire even though it is not always required with metal boxes and metal conduit.

[dburkhart]

what ever you do do alot of outlets I have 12 120 outlets and only one 240.BIG MISTAKE

[sawduster]

One of the benefits of the way I wired my shop, running two circuits on opposite poles to each outlet box, is that I can combine the two hots to make a 240 V outlet in any of the boxes if I need additional 240.

[woodmannie]

That's a good point on the split outlets. Easy 240v.
I put all mine it the walls, to start. Then I got a 220 saw, jointer, DC, Bandsaw. Duh!!! I never ran 220 outlets.
New shop will have 110v every 2-4 ft. And 220v every 4ft. I'm also gonna do some with Duster's idea(THANKS). My TS wont be moving much, so that line will be in the floor (thinkin crawl space below the floor for elec. and dust collection.)

Tom

[sawduster]

I've mentioned this on other 'lectrical threads, but . . .

I had the benefit before I wired of having experimented with tool locations in the shop for some time, so my machines were pretty much where I wanted them for my method of work. I ran a circuit in the attic area and added drop downs for those machines located away from the walls. These use stranded wire (round cross section) for the cords that drop down which run through rubber compression grommets to hold them in place. You can use locking female plugs on these, but mine seem to hold alright with just standard extension cord ends. Coming down from overhead, there's no cords on the floor, and the drop downs are out of the way of the path that the materials need when being machined.

[Beamer]

Nov 29, 2009 8:48:49 GMT -6 sawduster said:

One of the benefits of the way I wired my shop, running two circuits on opposite poles to each outlet box, is that I can combine the two hots to make a 240 V outlet in any of the boxes if I need additional 240.

Just a quick note about this technique. Most of the code i've seen requires that all 240v circuits have both hots bonded at the breaker. That is, a double breaker with the two tied together so that if only one leg trips, it forces the other one to trip as well. This is not just a code thing, but a safety thing.

So, to safely take that split 120v line and throw in a 240v outlet, the breaker then needs to be switched out to have a bonded double.

I'm not entirely sure if you're actually allowed to create 240v circuits on a split 120v line like that. It'd be wise to check your local codes for what's recommended, of course.

The only drawback I can see to bonding the hot leads in this case would be tripping one of the 120v hots would render the other one dead as well - probably not a bad thing.

One other note about this technique is that it usually means working in the box requires flipping BOTH breakers off so the entire box is dead. Not a big deal if you wired it or know that it's setup this way. But a less-responsible person may just jam their hands in there without testing.

Not criticizing, just notes. These were the reasons that lead me to decide not to go that route. I hadn't thought of 'em right away until an electrician friend pointed out some of the side effects. I figured I would just pass the info along.

[sawduster]

Yeah, I shoulda mentioned that in the original post. I used a double half size breaker with a pin across the "handles" so that if one throws, the other goes with it, and if I flip one off, the other goes off also. I did it that way before I combined the hots for the 240 V box because I didn't want someone else to get into any of the boxes not knowing there were two hot circuits in there.