There are a couple of previous posts about cutting EMT with a tubing cutter, but none that address my particular issue. I have some conduit sticking up 5 ft. out of a concrete floor, that I want to cut down to about 6″. I can get to the panel to turn off the power, but I cannot get to the pull-box to pull the wires back some. I want to continue to use the same conductors. There are three #12 THHNs inside 1/2″ thinwall, so it’s not packed tight.
My question is how can I cut the conduit without hurting the conductors inside? Again, they won’t be hot while I am working on them, but I sure wouldn’t want to risk a hack saw. Can I safely use a tubing cutter? How do I ream with the conductors in there after I am done? Or is there a plastic anti-shorting red-devil for conduit like the ones for BX that then protects the wire? Is my standard tubing cutter that I use for copper pipe adequate for the steel pipe, or do I need to buy some kind of new tool?
Whatever you tell me to do, I will practice at the 2′ level before I go down to final height near the floor. Thanks for your help!
Rick
Replies
Why can't you get to the pull box? If you've already covered it up somehow then your screwing the future up. You need to correct that problem or be cursed forever.
I would imagine you would find a small diameter pipe to slide inside for a sleeve and cut away. Seem pretty simple.
Hold my beer, and watch this!
http://www.hay98.com/
How about a tubing cutter like the ones used for copper. They cut emt and shouldn't cut through the wires.
Headstong, I'll take on anyone!
Just get a tubing cutter......I've cut galvanized with mine before without any problems......course it was an automotive tube cutter. Doesn't seem to be any difference between it and a copper cutter. It definately shouldn't hurt the wires if you go carefully.
Plus if you ruin the blade on it then you can buy replacements for most of them. To de-burr i'd get a small rat tale file and carefully do it.
A tubing cutter seems to be the optimum solution for this situation. The main objection is that, if the tube is cut all the way thru with the cutter, it will collapse the inner wall inward during the last few rotations. This causes a sharp ridge or burr on the inside. This must be removed.
The trick is to only cut about 7/8ths deep and then snap the EMT to break it at the cutline.
Since the wires are already present, a conventional reamer just won't work very well. There is a special mechanics or plumber's deburring tool which can handle this problem. It has a little hook-shaped, swiveling blade about an inch long. One on-line source is ask-enco.com Look under deburring tools.
[The link probably wont work because I imitated it.] [Use Google]
~Peter
Rick,
Using the smaller diameter tubing inside the EMT is a clever approach. Just make sure the ends are really smooth, and wrap the top end so that if you lose your grip, it doesn't fall down into the conduit coming out of the floor!
Or, try a new tool by Greenlee. It's an EMT cutter, basically a tubing cutter that scores 1/2" and 3/4" EMT most of the way through; then a quick snap, and the tubing breaks off. It leaves no burr inside, and supposedly doesn't deform the EMT.
See their website at Greenlee-textron.com (or something like that). I think the tool is still listed in the "What's new" section. Graybar (the gigantic electrical supply house) ought to be able to get one for you.
If you buy one and want to unload it after one use, let me know. I've been thinking of getting one.
Or, you could just try the approach with a regular tubing cutter. It'd be a bummer if you screw up, though. EMT crimped over and crushing the condictors....do ya feel lucky?
Good luck,
Cliff
While I don't think you need to protect the wires when cutting with a tubing cutter, it surely is easy to do just by sliding a 6-7 foot length of clear tubing over the wires and into the emt and securing the other end. 1/2" CPVC pipe is a nice tight fit into 1/2" emt and a 1/2" long piece could easily serve as your anti-short bushing.
I'm no electrician but more often than not I've cut emt with an iron pipe cutter and probably with a tubing cutter also with no apparent ill effects. I also, unlike you, had the luxury of being able to easily debur the emt sans wires.
Eric S.
So after you cut the EMT you are cutting the conductors and placing a box, right?
I've had to cut EMT with wires in it. Used a tubing cutter then used a chainsaw sharpening file to clean up the burr. If you have THHN insulation then the file shouldn't harm it. I'm going to look for that knew Greenlee tool though.
Hello. I'm Bos'n and I'm a tool addict.
If you haven't drawn blood today, you haven't done anything.
Hi Gunner,
>Why can't you get to the pull box? If you've already covered it up somehow then >your screwing the future up. You need to correct that problem or be cursed forever.
It's in my son's condo, reinforced concrete building converted from apartments. The pull box is in the ceiiling of the unit on the floor below his, then comes back up to the panel. Now that they are all owner-occupiedd, I can't just charge into another person's place. It's probably not covered up, just inaccessible to me.
And to BosN,
>So after you cut the EMT you are cutting the conductors and placing a box, right?
Yes of course. This is going into a "new" kitchen, and the existing pipe runs up inside a full height wall, that we are converting to a half-height with passthrough. This old pipe will serve the counter/peninsula receptacle. Needless to say there are several other circuits to add or modify to bring the new kitchen up to the new NEC.
As usual, the suggestions by Bill Harttmann and Dinosaur are ingenious. Thanks to all.
Rick
I'd use a tubing cutter followed by a swivel head debrring tool.
After cutting the EMT cut the wire to length, Then fold the ends over and push it down the conduit so that the loop is about an 1" below the top. Then you can either retrim it with a hacksaw or use a regular reamer.Then fish the wires back out.
Use a tubing cutter, then de-burr the inside with a small, pointy stone in a Dremel flex-wand.
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
I got a deburring tool from Ferguson's that has two rollers on parallel shafts on a pliers-type thing. Squeezing the handles moves the rollers farther apart. I think that would work if it has room for the wires.
-- J.S.
It sounds possible. I guess we'd have to try to find out. I got some old EMT lying around. You wanna send me the tool...or you want me to send you the pipe? ;-)>
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
Edited 8/26/2005 8:32 pm ET by Dinosaur
I dont do much with EMT, but when I do I use a tubing cutter.