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Surface mount conduit...

Jim Dawson

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Sep 24, 2008
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111
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East Alton, IL (near St. Louis)
I want to add a 240V and 2- 120V outlets in my shop. i want to use PVC conduit. Can I run all the THHN wires in one conduit? I have the 2 ganged 20A breaker for the 240 and 2 single 20A breakers for the 120 circuits Can I run all the wires in one conduit to a junction box near where the outlets will be then go from there or does each circuit need to be in a separate run of conduit?
 
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ard

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Feb 16, 2015
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Sierra Foothills... California
You can and should use one conduit- cleaner install.

Why PVC? Over time it will warp and not look nice and straight. EMC is pretty easy to run...LOTS of DIY posts here to help too.
 
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Jim Dawson

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Joined
Sep 24, 2008
Messages
111
Location
East Alton, IL (near St. Louis)
You can and should use one conduit- cleaner install.

Why PVC? Over time it will warp and not look nice and straight. EMC is pretty easy to run...LOTS of DIY posts here to help too.

I just assumed PVC would be easier to work with but maybe not. I don't have a tubing bender but maybe I can get by with connectors.

Thanks
 

ard

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It can be, but EMT really would be a superior look, IMO

Spend a few minutes- there are one or two guys that started thinking NM or PVC and we talked them into EMT. ;) They did great jobs. After a dozen fittings you will have paid for a bender. $10 on craigslist, 25 new on amazon
 

PoorOwner

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As far as I know PVC not allowed inside because of toxic fumes in case of fire. It is allowed and meant for outside.
 

SiGmA_X

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Portland, OR
I did 1/2" EMT. It was very simple. I did buy a couple of extra sticks to learn how to bend. My reason was exactly what Ard said - the fittings cost vs bender cost. Plus it looks cleaner. I bought a new bender for $25~30, I should have looked at CL but the time was a factor. If I had planned it out earlier I would have likely shopped on CL.

So you want to do 1x20amp 240v circuit, and 2x20amp 120v circuits? That would be 3 12ga for the 240, and 4 to 6 for the 120v. I think you can legally pull 20amp over 9 conductors in a 1/2" EMT as you're applying a 70% derating to a 30amp conductor... I'm not an electrician so take that with a grain of salt, but I'm sure someone on here will chime in and google pointed this to me a number of times.

https://solutions.borderstates.com/resource/conduit-fill-table/
 
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ddawg16

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S. California
As far as I know PVC not allowed inside because of toxic fumes in case of fire. It is allowed and meant for outside.

Care to show us the NEC section?

I'll check back in a couple of years for the answer.

PVC will only sag if subjected to sunlight and not properly supported.
 

teamextreme

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Lakewood, CO
As far as I know PVC not allowed inside because of toxic fumes in case of fire. It is allowed and meant for outside.

Jeez, I wonder what are your plumbing lines made of, what with the fire issue and all?

No such code restriction. Not NEC at any rate. There may be some oddball local restrictions.
 

Gmonkee

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May 9, 2010
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I did a conduit install in a shop. I was given a box of parts including pre bent corners and a **** ton of connectors. I never knew the cost.

Breaker boxes to 18 outlets all in steel and it was an easy install. Still looking good nine years later. I would do it again if wiring another shop.

Longevity makes the cost worthwhile.
 
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Moto

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Dec 9, 2007
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I'm in the middle of doing my garage with NM, and thinking of ripping it out and starting over with EMT.
 

PoorOwner

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Care to show us the NEC section?

I'll check back in a couple of years for the answer.

PVC will only sag if subjected to sunlight and not properly supported.

I was confused as I have read it wasn't recommended, but can't find anything about it not being allowed.

When I visit auto shops, costco etc, all are running EMT, never seen PVC on inside.

Bending EMT is kind of confusing at first, there must be some time spent learning it and you must pay attention very closely. I have done installed 50 feet hugging the walls, I only wasted one stick of it because I was starting on a different day and I was not paying attention, put the bender approaching from the wrong direction. The only tools needed was a hacksaw, file, and the bender. I only made cuts at the boxes on each end and it's not labor intensive or need to buy a cutter. It looks just like a pro electrician have done it.
 

alfredeneuman

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Fullerton, CA
Burning PVC conduit emits very toxic chlorine gas. Firefighters hate it.
Although there's no restriction in the NEC, it's not allowed in certain occupancies. I think it's written into some Fire Codes. I may be wrong though (it wouldn't be the 1st time)
(You could fill up the entire structure with PVC furniture, but not even an inch of PVC pipe, which seems sort of ***-backwards):wtf::rolleyes:
 
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grantw

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Nov 10, 2016
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Bay Area, CA
i'm going to be putting my garage together after the rest of the house is built, and I have settled on running 3/4" surface mount EMT everywhere. I don't want to keep parts for 3 different conduit sizes. Sure, I'll have 1.25" for my 100A sub, but 3/4 for everything else.... 3/4" is pretty damn versatile for a little extra bending effort.
 
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