Surface electric wiring, Metal or PVC?

[Yuri Sadykov]

I want to make "semi permanent" wiring in my shop, which is one car garage. Originally, I had regular 15A, 110V outlet there. I've got two extra 20A, 110V lines from my utility room, which is across the wall. I use two electrical extension cords to bring the power to my garage. Now I decided to make permanent wiring. I am thinking of surface mounting in conduits. I can go with metal or PVC conduits/boxes. PVC looks little bit less expensive and easier to work with, though metal adds not significantly more expenses and labor. So, my question is which is better, and WHY?
As for "semi permanent". If I decide to sell my house, I'd rather dismount all new wiring to avoid some problems.

[Rod Sheridan]

I use EMT (thinwall metal) for all my shop wiring.

Easy to bend, and I find it looks better than PVC...............Rod.

[Yuri Sadykov]

Rod,

what type of electrical boxes did you use with EMT? I went to Lowes and HD and could find acceptable ones, not speaking about 4 gangs.

[Jason Fastenau]

I second the EMT. One thing I wish I'd done in my shop was put the outlets at 54 inches instead of 48 like I did. The higher outlets would let you lean plywood against the wall underneath the electrical runs.

[Richard Jones]

I use EMT (thinwall metal) for all my shop wiring.

Easy to bend, and I find it looks better than PVC...............Rod.

And magnets stick to it!!!

To me, PVC IS a bit easier, and I do own a bender. That said, the EMT will break down completely with no loss of parts, unlike the glued PVC.

Which is better? The one you choose, of course.........

[Yuri Sadykov]

That said, the EMT will break down completely with no loss of parts, unlike the glued PVC.

Well, but I do not have to glue PVC! just leave it like EMT, that's it.

[Von Bickley]

I use EMT (thinwall metal) for all my shop wiring.

Easy to bend, and I find it looks better than PVC...............Rod.

I agree with Rod. That's the way I wired my shop.

[John Cooper2]

EMT, More durable, not much harder to work with.

Hadn't thought about it, but I do like the look of emt over pvc.

Metal boxes for the emt, any big box store will have what you need.

[Rod Sheridan]

I used 4" square surface mount boxes, each had a 120V duplex and 240V duplex wired as a multi-wire branch circuit.

One 2 pole breaker gave me 2 X 120V circuits and 1 X 240V circuit in each box.

I have 4 of these boxes in the shop for machinery and general use...........Rod.

[Bruce Wrenn]

EMT and multi -wire branch circuits. With EMT, you don't have to pull a separate ground wire, which saves some $$, and time. I would use a duplex 120 recpt, and a single 240 recpt at each location. If you have to have 120 GFCI recpt's, feed through the 240 first. For some reason, duplex 240 recpt's cost a fortune. Just bond the recept's to the boxes for the ground. PVC tends to sag over time

[Steve Meliza]

I'll add another vote for EMT over PVC, mainly for the looks and durability. I did a lot of bending of 1/2" EMT and it came out pretty nice even for this rookie bender. You can either buy a lot of expensive EMT fittings or a bender, but I'm not sure what the PVC options are for making bends. Although I wouldn't do it myself, if you run all EMT everywhere you can use the conduit as your ground (up to 30A with 1/2" EMT) which might save you a little money.

Why would you need to dismantle to avoid problems when selling? To me that either means you fear that sellers wouldn't want to buy a house with a useful electrical upgrade or else you plan to do some un-permitted work. Unless a single woman buys your house there will be an increase in appeal to perspective buyers if they see a legal and quality upgrade to the electrical. If you or someone else does dismantle it later on then PVC goes in the landfill while EMT goes into the recycling.

[ron hokenson]

equipment grounding conductors are required in EMT. It's been alot of years since the raceway could be used as an equipment ground. Table 250-122 in the National Electric Code gives the minimum size equipment grounding conductor for grounding both the raceway and equipment. When not sure, call the sate electric inspector and ask what is required. As an example, a 20 amp circuit is required to have #12 wire (copper) as an equipment ground.

[Steve Meliza]

equipment grounding conductors are required in EMT. It's been alot of years since the raceway could be used as an equipment ground.

Horse manure.

358.60 Grounding. EMT shall be permitted as an equipment grounding conductor.

250.118 Types of Equipment Grounding Conductors.
The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following:
(4) Electrical metallic tubing.
(15) Surface metal raceways listed for grounding.

That said, the code is the minimum allowed and I only quote it for truth, I advocate running a copper ground wire inside of EMT as it is more reliable (no fittings to come loose or get disconnected).

[Ole Anderson]

Another option would be to pull THHN through WireMold. More pricey than EMT, but it hugs the walls better.

[Jerry Hillenburg]

I am retired now and my commercial cabinet shop has turned into a hobby shop. It has an electrical system that is primarily EMT (Electrical Metallic Tubing). I like it that way. Since I built the shop 28 years ago I have modified the electrical system continuously. I have found the ability to modify my shop's electrical system crucial because of new equipment and equipment being moved to different locations.

When I first built my shop, I hired an electrical contractor. I fired him after four hours on the job. My cabinet business was my passion - it was what made me excited to start my day at 4:00am and I was not having a sloppy electrical installation in my new shop. I bought a copy of the book "Wiring Simplified" by H.P. Richter. With that book and the mentoring of an electrician friend I installed the electrical system myself. The 2011 version of “Wiring Simplified” is the 43 edition - the first edition was 80 years ago. I think every shop should have a copy of this book. $9.39 Amazon. http://www.amazon.com/Wiring-Simplif.../dp/0971977976

Because of experience, I will never use ½" PVC or EMT conduit again - it is to small for potential future wiring modifications. Before I poured the concrete floor in my shop, I installed ½" PVC conduit from the breaker panel load center to locations where I felt wiring would be needed. One ½" PVC conduit run is to my multiple table saw island. Packing all the #10 and #12 THHN wires in the ½" conduit was a chore and probably violates code. When I built a finishing room addition to the shop, I installed 1” PVC conduit under the concrete from the breaker panel load center to all four walls, then ran ¾" EMT from there for the outlets on the walls. I did it right in the addition and it works great. I now feel an ideal system uses primarily 1" PVC conduit under the concrete and ¾" EMT above the concrete with 4”X4” metal boxes that are 2” deep for the outlets.

Before I installed florescent lighting in both the shop and the addition, I installed 4"X4" metal wire-ways (similar to busway or auxiliary gutter but technically not the same) http://www.austinenclosures.com/products/view/NEMA_1_Hinge_Cover_Wireway . I connected the wire-way to the breaker panel load center with 2" EMT. The wire-way with it's full length hinged doors makes it easy to wire the lights and to install new EMT runs to just about anywhere in the room - just drill a hole in the side and install your new EMT run from it.

All my 240 volt equipment has #12 SO cords with Kellums cord grips to support the cord at the receptacle. http://www.grainger.com/Grainger/HUBBELL-WIRING-DEVICEKELLEMS-Cable-Support-6C097? I like SO (600v) cord better than SJO (300v) cord because it has thicker insulation that will withstand the abuse of everyday use better - I know this is overkill. My local Home Depot stocks #12 SO cord, yours probably stocks it to.

A good shop is always changing and evolving - a good shop is adaptable to your future needs. I believe most woodworkers reading this post will never be able to say, "My shop is completed, no more modifications." Make sure your electrical system is adaptable. A carefully planned EMT system, supplemented with PVC conduit under the concrete and wire-ways on the ceiling, makes it possible.