Running Conduit for wiring

[icnsltmfg]

Because my walls are already rocked, I must run conduit for all of the new wiring circuits. I have never run conduit before and do not want to buy too many single use tools. What are the pro's and con's of EMT vs PVC. Also what size should I run to min the number of tubes? I believe the max is 2 cables per tube correct? I plan on using 20amps for both sets of light circuits and for both sets of outlet circuits. I will also have a 30amp line for the 220V Lift which only pulls 9amps. I believe I would have to run 12-2 for all of the 20amp lines except for the 3-way lights which would be 12-3.
Adam

 

[Steve in Mi]

Rental places have the benders if you don't want to buy any.

This statement has me concerned;

I believe the max is 2 cables per tube correct?

Depends on the wire size and the tube size. I'm sure you can find lots of info on the web about running conduit and the fill requirements - I invite you to dig into the literature or call an electrician to do the job for you.

FWIW, I always carry an equipment ground wire in conduit, in plastic because you have to and in metal emt because I trust it more than the possible corroded joints a few years out.

 

[RPH]

Cables don't go into conduit. Use Thhn or thwn wire but it's against code to run romex in conduit.

 

[timgr]

AFAIK you can run Romex on the surface as long as the wire isn't in jeopardy.

One possibility is to put junction boxes at the top of the wall and run Romex to them around the top plate, out of harms way. Then run EMT with THWN from the boxes to your fixtures.

Pretty sure you won't be able to find enough info about wire sizes and conduit on the web (I've tried). You'll have to consult a book with the NEC - try your local library.

 

[boiler7904]

The tools to run conduit are fairly cheap - cheaper than renting if you end up using them for more than a day or so. You're looking at a bender, reamer, screwdriver, and a hacksaw that you probably already own. Buy them and sell them when you're done. It's also possible to run conduit without bending it if you know which fittings (LBs) to use and where.

You can run more than two wires in one conduit. It all depends on wire size, number of circuits, amperage, wire type, temperature rating, run distance. In other words, you need to get real familiar with the NEC. 2005 is the current version and 2008 is coming out now. Find out what your AHJ will enforce even if you're not going through the whole permit / inspection process.

As far as I know, it is legal to run Romex in conduit but you can do less of it because the sheathing contributes to conduit fill. It's also wasteful since bare wire is cheaper than Romex. Romex is not allowed to be run open where it can be physically touched.

 

[wilbilt]

I always run a minimum size of 3/4", even if I can get away with 1/2". It seems I'm always trying to stuff more wire in it a year later...

 

[Steve in Mi]

Pretty sure you won't be able to find enough info about wire sizes and conduit on the web (I've tried). You'll have to consult a book with the NEC - try your local library.

If you Google "conduit wire fill" a bunch will jump at you. The NEC Appendix “C” covers it. Small hand guides to wiring are available at Lowes, HD etc., etc. that contain the tables to guide you also.

These can get you started;

http://www.lanshack.com/DesigningConduitRuns.aspx

http://www.selfhelpandmore.com/homewiringusa/2002/definitions/calconduitfill/index.htm

 

[Aceman]

Cables don't go into conduit. Use Thhn or thwn wire but it's against code to run romex in conduit.

WRONG! Romex can be installed in conduit as long as you follow the conduit fill requirements.

To answer the original posters question, I would pipe everything in 1/2" emt. All you will need is a 1/2" bender and a reaming tool assuming you have a drill, saw, etc. 1/2" emt is usually fine if you're only going to have lights, receps and maybe a compressor in your garage. If you have a big welder you'll need a larger pipe.

Here's an online NEC codebook:
http://www.nfpa.org/freecodes/free_access_agreement.asp?id=7005SB

Annex C has conduit fill requirements.

I would suggest buying rolls of thhn wire rather than trying to pull romex into conduit though. The frustration saved will be worth it.

 

[icnsltmfg]

WRONG! Romex can be installed in conduit as long as you follow the conduit fill requirements.

To answer the original posters question, I would pipe everything in 1/2" emt. All you will need is a 1/2" bender and a reaming tool assuming you have a drill, saw, etc. 1/2" emt is usually fine if you're only going to have lights, receps and maybe a compressor in your garage. If you have a big welder you'll need a larger pipe.

Here's an online NEC codebook:
http://www.nfpa.org/freecodes/free_access_agreement.asp?id=7005SB

Annex C has conduit fill requirements.

I would suggest buying rolls of thhn wire rather than trying to pull romex into conduit though. The frustration saved will be worth it.

Thanks for the input...I had checked with the town and Romex was fine through EMT, and I had assumed with my layout that I was not going to need to put more than 2 cables through each conduit. If will look at the thhn as that may be less of a headache.

I will prob be running all of the conduit, running the wire, and attaching the switches / outlets, but have my electrician check before closing, attach to the sub panel and home run back to the main panel.

I would like to get more experience, but I also do know my limits and will not cut corners.
Thanks Adam

 

[Charles (in GA)]

"Romex in conduit" While perfectly legal, the code even explains how to calculate the fill with cables like this, you do not even want to try this. You will very quickly be hating life and the fact you ever thought about doing this. I have done this on two occasions, and no amount of pull lube in the world will get you thru without leaving you wondering how much you stretched the cable.

You do need to get yourself some good references however. Every time you think you have it all figured out, another variable enters the picture.

Charles

 

[FL_Javelin]

Definitely consult an electrician before doing and PLAN all you can first. I ran up to 9 wires in 1/2" EMT though it was tight.

Lesson I learned from school of hard knocks, DO NOT let the girl at HD/Lowes roll up all your colored wires in one roll, do them individually otherwise you'll have a mess, do each individually.

Unroll all wires out flat before you pull, so much easier. Had I known above, it would have saved me about 3 hours.

 

[dipper]

I would never run romex in conduit, unless only in small section to sleeve it as it passed thru a cement wall or something. Comparing the price of emt versus pvc, you will probably lean towards the pvc as it will be much cheaper. And get yourself a couple roll's of 12awg THHN.

 

[Vermaraj]

Emt is easy to bend. You need a $20 tool from HD and about an hour to figure out how to measure for offsets or bends. Mike Holt forums has the bending instructions on line. I think depot may even have pre bent 90s and offsets.

PVC requires a blanket (about $100) or a heat box to bend ($800). I don't know if you can rent these or not. Again HD has prebent 90s and offsets. If you try to bend it with a hair dryer or heat gun the bends will be too tight and the inspector will most likely make you rip it out.

Pulling romex through either conduits is possible but its a nightmare. Pulling a flexible 1/8" thick wire through is no problem. Even pulling 10 at a time is no problem until you get over 200' of friction.

Romex will twist when going through a bend and flex against the sides of the conduit. You will be fighting the friction of the cable your entire pull. Over 20 feet you will have both feet against the wall pulling with both hands wyl-e-coyote style.

If you really want to pull romex through conduit do yourself a favor and get a bucket of wire pulling grease. Use clothing you intend to throw out.

Last thing. Every 360 degrees of bend requires a pull box.