Now that you've read part 1 and have all your equipment on standby, let's move on to part 2 - Metal Conduit Installation.
As I mentioned in my opener, once you get the hang of it, installing conduit is pretty simple.
(For the simplicity of this article, I will be talking specifically about outlet runs but the same ideas apply when running your lights)
Step 1: Installing Metal Conduit Outlet Boxes:
Usually the "new work" blue boxes come with pre installed nails. I recommend the similarly designed "new work" metal boxes which have metal tabs you tack into place, followed by a couple of wood screws to fully secure the box.
They make a variety of these boxes though, so
pick out whatever feels right to you.
For more info on "where" to place you outlets and lights, read this article on planning your electrical.
Step 2: Installing Metal Conduit Junction Boxes:
This is the part of metal conduit installation that's the most different from routing Romex. When running Romex, you typically would route from one outlet box, to the next by drilling holes in your studs and fishing the Romex through said holes from box to box.
Since metal conduit is not flexible like Romex though, you cannot fish the conduit through the studs. Therefore, you have to take your runs vertical to the ceiling. Once they are up in the ceiling, they still have to be all connected which is where junction boxes come in.
Planning the position of the junction boxes:
This is more art than science. You generally want boxes positioned so you have a clear path for your power coming in, your outlet runs going out, and assuming this isn't the last junction in the run, another power run going out to the next junction.
Here is where your ceiling choice comes into play.
If you are doing a drop ceiling, you can mount these junctions (and conduit) directly to the bottom of your floor joists which means less bends.
If you want a drywall ceiling you have to tuck these junctions up in between floor joists.
Alternatively, you could mount everything to the bottom and install spacer boards across your entire ceiling to mount your drywall.
To me, this seems like more trouble than its worth, but for those you anti-drop ceilingers out there, this could be a viable option.
For me, the contractor/previous owner already had the majority of the existing conduit nailed to the bottom of the floor joists. I wasn't about to reroute all that, so the decision to install a drop ceiling was made for me!
Step 3: Connect the conduits and junction boxes together
Remember our friendly conduit bender? Now's the time to bust him out.
In this stage you will run the conduit from the outlet boxes to the junctions (or other outlets depending on your layout). Remember - Patience is a virtue!
Come to grips right now with the fact that you WILL screw up and waste several pieces of conduit making incorrect bends. Life will go on, and at worst you've wasted $1.75. If you get really frustrated, take a break and come back later.
5 BONUS Tips for Installing Metal Conduit
1. Use as few bends as possible - The more bends, the harder it will be fish wire later. Don't quote me because I'm not an electrician, but I believe there may even be a code as to the max number of bends in a run for that reason. One reader mentioned 360 total degrees in a run.
2. Use as few connectors as possible - Same idea as less bends. Don't connect 3 two-inch pieces of conduit together just because you don't want to waste them. Cut 1 6-inch piece from the start. Again, it's like $0.20 you are wasting.
3. After you cut pipe, ream the inside of the conduit. Ensure there are no sharp burrs that could damage the wire sheathing and cause shorts while pulling wire.
4. Cut conduit long! When measuring conduit lengths, err on the side of too long, you can always trim it shorter.
5. For certain areas where you can't avoid running to the ceiling (half walls for example) you can run conduit similar to romex. However, instead of drilling a hole through the studs, you have to notch the edge of the stud deep enough for the conduit to be below the face.
You can use a plunge cutter or circular saw for this, and cleanup with a chisel. Don't forget to nail in protector plates when you are done!
Step 4: Running Wire
If you have done everything right, this should be the fun/easy part - running your wire.
Run your fish line from one box to another. Attach your wire to the fish line, and pull it back through.
Leave plenty of slack for making your connections. If you are performing this on your own, here's a quick tip. Run a spare piece of conduit through your wire rolls and set it on top of a garbage can. This way the wire pulls off the roll nice and easy without making a mess of your roll.
Step 5: Wiring Your Outlets
Wiring your outlets is just like using Romex, so I again won't go into great detail. See Jason's electrical page for more details about this part.
DONE and DONE!
Congrats, you have successfully installed a metal conduit system, simple right?
It took me about a month off and on to get this finished. I was glad I did it, but if I could go back, I might have just hired an electrician to speed that up a bit.
Oh well, you live and you learn and now I have hopefully taught you readers a thing or 2 too!
ps. Here's part 1 if you missed it. It's all about the tools you'll need to install metal conduit for your finished basement.