Easiest way to enlarge an electrical knockout?

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I used to use the nibbler tool all the time when I did electronics work. I made a lot of little gadgets when I was younger. These days the nibbler just sits in my tool chest, out of sight, out of mind. It was nice to be able to make use of it again.
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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On 2/24/2014 9:09 AM, HerHusband wrote:

that have only one function unless I use it often. ^_^
TDD
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On 2/23/2014 9:17 PM, HerHusband wrote:

2) Now, you have a hot ceiling, and cold floor. You need either a ceiling fan, or infrared heaters, to warm the floor. Maybe Wirsbo in floor heat.
That's an impressive web page for a 3/4 inch knock out story.
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Christopher A. Young
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The dangling cord would have bugged me even if it was painted white. I'm funny like that.

Unless I'm working under the car, I'm usually not laying down on the floor. So that's not really an issue. Besides, the fan in the heater does a good job of circulating the warm air in the room. As long as it's comfortable to do a little woodworking or a project at the workbench, I'm happy.

I thought about installing heating tubes in the slab when we built the garage. But, I couldn't justify the extra expense since I only work in the garage occasionally. Radiant floor heat would have been slow to respond, and I'm usually only in the garage a few hours at a time. It's easy to go in and flip on the electric heater while I'm working, then turn it off when I leave.

I couldn't find much information on installing the FUH54 heater when I ordered it. The owners manual that comes with the heater is also rather limited. So I thought I would document my installation in hopes it would help someone else in the same situation. The 3/4 inch knockout situation was just an unexpected side project that worked into the story. :)
It took less than an hour to put the page together, so why not...
Anthony Watson Mountain Software www.mountainsoftware.com www.watsondiy.com
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On Monday, February 24, 2014 9:23:24 AM UTC-6, HerHusband wrote:

Please don't answer the stormin' moron point for point...it only gives him more fuel to be senseless! *L* (I agree about painting the cord...it would look tacky)
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On Monday, February 24, 2014 9:23:24 AM UTC-6, HerHusband wrote:

SM: Ah, so you want a fast acting device you can flip off?

SM: Glad that worked out.

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Christopher A. Young
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I rest my case...
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Personally, I would have used a length of 1/2" flex conduit with #12 THHN rather than using a "dryer cord" for this particular installation. No need to enlarge the knockout, and the wiring is somewhat protected. A flat metal cover plate with a knockout would hold the flex connector on the outlet box side.
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The heater draws about 22 amps, so I needed four #10 wires to accomodate the external switch.
I originally planned to direct wire with flexible conduit, but changed my mind at the store. I didn't want to buy four rolls of different colored THHN wire, and if you've ever tried to have wire specialty cut at the box store, you know what a hassle that is. I couldn't find the conduit connectors, they didn't have the cover plate with knockout in stock, and it was becoming more trouble than it was worth.
Grab a dryer cord, receptacle, and cover plate. Done. :)
I'm glad I went with the second approach as I've already taken the heater down twice.
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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On 2/25/2014 6:04 PM, HerHusband wrote:

And that's just in the first half hour after you got the job completed? OCD much?
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It was actually over a three day period, but yeah, I do tend to overthink most things. :)
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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On 2/25/2014 6:29 PM, HerHusband wrote:

maintenance. A lot of the installations of equipment I've seen over the years have been thrown in as quickly as possible and as cheaply as possible. It adds to the cost of maintenance for a customer because of the time it takes to remove and replace it. ^_^
TDD
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Ah, I thought I had read that it was 2.2kw. At 220, that's about 10 amps, which is why I suggested #12AWG.

As I usually have several spools of 12AWG THHN available, that hasn't been a problem for me (and my local hardware store, OSH, is pretty good about cutting custom lengths when I do need something I don't have). I tend to avoid the orange and blue stores, but I understand that isn't an option for everyone.

I put mine up (3.5kw) a dozen years ago in the garage (a dayton unit) and have never needed to take it down. Then again, it's wired with EMT and hung from unistrut, so it's not particularly _easy_ to take down either.
For mine, I put both a DPST and Thermostat in circuit so I'd never need to go near the heater and could completely disable it during the 10 months when it is never needed.
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On Friday, February 21, 2014 8:46:34 PM UTC-5, HerHusband wrote:

Harbor Freight has step drills for relatively cheap. I doubt they're any *good* but as long as they make one hole, it's probably the easiest way to go.
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On 2/23/2014 1:00 PM, N8N wrote:

one hole, it's probably the easiest way to go.

Years ago, when I did heating. HF has a three pack of step drills up to 3/4, but that's not big enough. Need one which goes to 7/8, and the knock out size is 13/16.
Two pack: http://www.harborfreight.com/2-piece-titanium-nitride-coated-high-speed-steel-step-drill-bits-69088.html
Either of these two should make 13/16 hole.
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On 2/23/2014 2:46 PM, Stormin Mormon wrote:

store. The first one lasted until the mid 1980's when I broke it while installing a set of automatic doors in a grocery store. The originals manufactured by The Unibit Corporation seemed to best and longest lasting. ^_^
TDD
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You didn't show a picture of the side of the heater where the old hole was and how you filled that hole in!!
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I used a standard knockout seal like these:
http://tinyurl.com/mkjqkp8
You can also see the back side of the seal on the right side of the picture in the "Rewiring the new cord" section of my web page:
www.watsondiy.com/heater.htm
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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This has been one of the best threads on AHR in a long time, with the results actually being available for everyone to see and discuss in a civil manner.
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