Shop Wiring Questions (Longish)

On Sat, 9 Jul 2005 9:35:06 -0700, Doug White wrote (in message ):

Many juristictions adopt the National Electrical Code in total, but some modify and/or add to it. You should talk to your local electricians/authorities for the final say on what is legal in your area.

Running Romex in conduit is almost never done and the NEC does not directly address this issue,IIRC.

IMHO, running Romex behind the metal baseboard would not require any additional protection (other than grommets, as you mentioned).

Another option you might consider is "Surface Raceway".

Hope this helps.

Roger in Vegas

PLease do not do something similar (tying two separate circuits into one 220V outlet).

Run two separate 110V circuits, and one separate 220V circuit, all protected by their breakers.

I would strongly recommend installing a subpanel in your shop. That would let you have a variety of circuits (110 and 220), and run only one cable to the shop.

In my location, running romex in metal conduit is not allowed.

i

Not that safe - When you run a 220V outlet, it has to have both sides of the circuit on a breaker with a common trip handle-tie. Otherwise you can trip out one side and the 220V motor stops - but the outlet is still 120V hot on one side to ground. Can cause you some serious unwanted excitement when you grab that "dead" receptacle.

I'd strongly suggest running a separate 3/4" conduit (flex or EMT) with a 4-wire #8 THHN Copper circuit (2 Hots, Neutral, Ground) to a separate 4S steel box on the wall. You can always change out the receptacle and the breaker feeding it to whatever you need at the moment, but that's enough for a 50-amp welder plug.

And you run the neutral in the 4-wire circuit back to the panel just in case you ever want to install a 4-wire receptacle and run a mixed

120/240V load - you aren't allowed to run ANY incidental neutral loads (like lights, controls or fans) back on the safety ground wire.

You can not run Romex cable exposed in an occupied space, period. The attic and crawl space are not occupied spaces, garages and finished basements with easy access are.

For a Romex circuit that terminates in the garage or an occupied space you can slide a piece of flexible conduit over it as armor where it comes out of the wall, but don't plan on pulling it all the way through. The outer sheath gets hung up on everything.

Make it easy on yourself - don't fight ripping he walls open, just run EMT tubing on the surface. Practice with the bender so the bends are all neat and pretty, clamp it down well with straps to the studs or joists so it wont move, and then paint it to match the room. The paint will make it all but disappear.

It's a stupid basement, not your front entry hall... :-0

Would you STOP with the thinking "Romex, Romex, Romex" already? ^_^

The old rules still apply - You can still go all the way from the panel to the loads with regular wires in conduit, and not 'turn it into Romex' at any point along the way. Conduit is a much better way of doing it, because if you put enough pipe into the walls (including a few spare boxes in strategic places) you'll never have to open the walls up ever again.

With conduit, if it goes open or you need a heavier circuit there you open the boxes and repull the wires, done. When Romex goes bad in the walls it's like Ben Grimm says: "It's Hammerin' Time!" ;-)

There really isn't a fill table for Romex in pipe, because the sheath and paper filler throws the wire area cross section charts right out the window. As a practical matter, one 12-2 or 12-3 Romex in 1/2" pipe is full.

You can get 10 #12 THHN wires into 1/2" conduit - that is enough for

6 circuits (3-wire) and a #12 ground wire. (Do NOT trust the pipe as a grounding conductor, always run a green wire.)

You can get 3 #8 THHN and a #12 ground in 1/2" conduit for the 50A welder receptacle if you are careful. (The #12 ground wire puts it just a hair over "legal fill" but it's also not a current carrying conductor - gray area.)

Or go buy yourself a 3/4" EMT bender - they're $35 new at The Borg (Home Depot or Lowe's). Or go find one at a garage sale for $1. They are very handy, because they also bend 1/2" Rigid conduit or gas/water pipe. Though building inspectors might get nervous if they see a saddle bend in a gas pipe going around an obstruction...

PVC Plastic conduit could be used, but is usually reserved for outdoor work and concrete embedment in and under the slab. I really would not suggest using it exposed indoors because it burns (and makes lots of smoke), and you don't need to add any more fire load.

Run a separate EMT or flex run from a box on each basement wall up and over to the sub-panel, from each support column in the 'middle of the room' over to the sub-panel, and blank off the boxes that you aren't using yet.

When you decide to add that planer in the middle of the shop, or a new bench grinder in the corner, pop the cover off one of those 'spare' boxes and run whatever size wires you need.

If there are more than four bends (360-degrees worth) in any run you have to stop at a pullbox along the way - or you'll have a heck of a fight getting the fishtape and the wires through later. Again, it's a basement - if there's a pullbox blank cover poking through the ceiling, who the heck cares? Paint it white.

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This of course is the correct way to do the job. Run it in pipe. The only time I see NM cable ("romex") in EMT is where it has to run over brick or stone and needs some mechanical protection.

THe electrician who wired a couple of circuits in my house did that in the basement - NM cable that drops out of the overhead, crosses over brickwork, and ties to a box on the wall. He slipped pieces of EMT over the cable to provide mechanical protection.

Jim

Doug, Why go low? What is on the ceiling? If the ceiling is finished, could you possibly run wires behind a nice molding that runs along the wall/ceiling intersection to the areas you want to access? The cove moldings are made in various sizes and will have a void area behind them which may give you room to run the conduit. HTH Ken.

Go over to your friendly electrical supply and ask about some stuff called "WireMold." It is a finished conduit intended to be run on the surface of a finished wall and still look nice. You run separate wires inside of it (not Romex). It will hold about 3 10AWG or 5 12/14AWG wires.

Jerry

Question for Bruce: I sgree that **SEPERATE** breakers are bad but how about running the same setup (2 opposite side hots, neutral, and ground) off a **220** breaker? Overload on circuit 'A' will trip that side and the other side 'B'.

In my case, I have a single person shop where I may run a 240 volt table saw, but can't run the router at the same time. Or I may run the shop vac on one circuit and the 3hp router on the other circuit.

As background, the lights are > >

Just fine, AFAIK. As long as you don't get a half-trip situation.

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