220v extension cord for Table saw?

[mac davis]

haven't used it in years, but I think you do, if you look young (i sure don't!) between the sniffers and the taggers, they used to sell a lot of spray paint!

[Brett A. Thomas]

Hey, Bob, you see that great article in Tools & Shops this month about shop fires? ;)

-BAT

[Charlie Self]

Brett A. Thomas responds:

And why would 240 volt extension cords be any more likely to create shop fires than would, say, 120 volt extension cords?

Charlie Self "Giving every man a vote has no more made men wise and free than Christianity has made them good." H. L. Mencken

[Robert Galloway]

Yup. Saw it. Don't see where it applies???

bob g.

Brett A. Thomas wrote:

[Brett A. Thomas]

Just a joke, Charlie. Although, FWIW, I'd tend to be a little more suspicious of shop-made extension cords (whatever their voltage) than of the UL-listed ones. No disrespect to Bob's cable-making in particular intended, though.

[Robert Galloway]

My 10-3 awg extension with heavy neoprene cover and carrying 220 volts will probably stand up to more than most of the extension cords I've seen contractors running around job sites carrying 110 volts. Amps versus wire guage are probably most important in overheating and general construction will determine how well it stands up to foot traffic and having things rolled over it such as mobile base mounted tools or wheelbarrows.

bob g.

Charlie Self wrote:

[Dave Hinz]

Well...if you're using UL listed connectors, and UL listed wire, and using both according to how they're supposed to be used, you're fine.

An interesting side note - coiling of extension cords while in use is a really, really bad idea. It makes a huge inductor (coil) which blocks AC current and generates a LOT of heat. I have a friend who is a master electrician, and among other jobs always handles the power systems at the county fair. He's got more than a couple trophies which are melted-together coils of what used to be extension cords on reels of one sort or another. Power loss is substantial in a coiled AC cord.

That said, I have no hesitation making my own extension cords where appropriate, but I do the calculations before I do so.

Dave Hinz

[Brett A. Thomas]

Sorry, just the first thing that popped into my head when I read it. Not trying to make any particular criticism of your electrical choices, meant to be lighthearted joshing.

[Mike Marlow]

Would you be equally more suspicious of shop made wood products than of commercially manufactured ones?

[Brett A. Thomas]

Well, I don't believe most common wood furniture goes through quite the UL-sponsored torture testing most extension cords do, so I don't think that's particularly a fair question. I also think most shop-made cords are probably not as extensively designed and engineered as most shop-made wood products. And, finally, if I mess up a bench in the shop, it's probably not going to catch on fire. [Pauses briefly to imagine screwing up a bench so badly that it bursts into flames].

Anyway, I was just trying to make a lighthearted comment and apparently have now offended half of rec.woodworking. I'm sure at some point I'll make an extension cord myself and it'll work just fine. All I'm saying is it'll be six months before I stop looking at it carefully everytime I use it - and that wouldn't be true of a UL-listed extension cord.

-BAT

[Greg]

Before you get too happy with the U/L approval remember they approved aluminum wire, FPE "no-trip" breakers and a back stabber wiring devices.

[J]

I have some nice homemade 220V cords made up from 10GA SJ cable with hubbell twistlocks on the ends. They beat the pants off any factory made cord I could buy at the borg. No need to look at them twice. Can you really be that doubtful about your skills and of electricity?

-j

[Lew Hodgett]

And the list goes on.

It is a test for fee organization, not an engineering design firm.

Lew

[Charlie Self]

Brett Thomas notes:

You haven't offended anyone, AFAIK. But, in fact, shop made extension cords are fairly common, both in 240 and 120 volt configurations, and the parts used have--usually--already been engineered and tested. It's a matter of assembly, and that's an individual thing. My hands aren't as able as they were back then, but I used to rewire military helicopters. Those systems were already engineered, but for various reasons (including shitty engineering) problems cropped up and us avionics types had to hunt it down and fix it, often makikng field changes. So I feel pretty competent to make shop extensions, and I do not feel my level of wiring skill is at all unusual.

One good examination should do it. If you assemble the cord of top quality components and do the work carefully, it will show you all you need to know the first time you use it.

Charlie Self "Giving every man a vote has no more made men wise and free than Christianity has made them good." H. L. Mencken

[Mike Marlow]

Hey Brett, I'll throw this in out of order, just to set the stage... not to worry - you didn't offend anyone.

Part of what folks tend to respond to is the drama of statements like this and the drama implied in what you originally threw out there with your first comment. It might be that you intended no such drama, but there is a whole history of usenet that preceeds you and folks become somwhat conditioned. We're used to seeing people who make comments about requireing UL approved cords often times having no clue about building a simple extension cord that is many times more reliable, safe, suited to its use, etc. than the UL tagged product from the local department store that others seem to take refuge in. Too often its the UL tag that satisfies the uninformed user, and not the construction of the cord. Those fires you refer to are typically not "burst into flames" type of fires (drama). In fact, I'd go so far as to say never. Electrical fires are slow starters, and most typically from such causes as under rated UL approved cords.

As to most shop made wood products being well engineered, I'd suggest most are very poorly engineered. Over built because of a lack of real engineering. Not that it's such a bad thing, but I certainly would not agree with your statement above. There really is not much engineering to a properly constructed extension cord. If you can trim insulating material, operate a screw driver, and have a modicom of common sense, a well built extension cord is well within the reach of most anybody.

Nah. No offense. But... your comment above makes it appear you comments are not so light hearted. Maybe because you don't do any electrical work? That would seem reasonable enough. People who don't understand something are often afraid of it.

Just be sure to post pics on abpw...

Oh, take the plunge - build one. You'll never be the same afterwards. Here's a guess - I bet you are using UL approved cords that are more of a fire risk right now than any cord that most people here would build for a given application. Placing too much confidence - any confidence in a UL tag, to the exclusion of any other understanding of electricity is more of a fire/shock hazard than what you'd face with a properly built cord.

[Bob Martin]

if only yours were the most offensive comments to be found on usenet ...

[Brett A. Thomas]

Well, it's probably just me. But I did that with wiring in my house and it was at least three months before I stopped thinking, as I drifted off to sleep, "gee, I hope that keeps working..." My two big goals in life are to make it through without going to prison or burning my house down. :)

As a serious question - doesn't NEC kinda frown on "permanent" extension cords? Would it be safer to replace the cords on your tools with longer, permanent ones? Or is this what you guys have been talking about, and I misunderstood?

-BAT

[Brett A. Thomas]

Actually, I do a lot of my own electrical work. I have about twenty years of hobbyist experience with low-voltage stuff, but my recent acquisition of a 60 year-old house that was previously cared for by chimpanzees has forced me to become a hobbyist electrician. I've rewired a bunch of circuits in my house because the old ones were unsafe (and didn't do what I wanted), and I've placed a subpanel in my detached garage (shop), put in powered smoke detectors, replaced a doorbell and tranformer, and run new outlets. I'll be doing all the wiring, lighting, etc. in my shop, starting as soon as I get back on my feet from knee surgery and get all the boxes of stuff out of it.

All I'm saying is that, as a Apprenctice-level electrician with no Master in sight, all that wiring's going to have to work for a while before I completely trust it. And that's not true of an extension cord I get at HD - I've never once plugged in a new extension cord and thought, "I hope this works." I don't see why that's controversial, evidence of my lack of understanding of electricity, or proof that I don't trust my own workmanship. Maybe after I've got ten years experience working with 120/240 wiring I'll not think twice about my wiring. But, not yet.

-BAT

[Charlie Self]

Brett Thomas asks:

An extension is some of an impermanent tool by its very nature. AFAIK, for hobby tools the NEC doesn't say a thing about putting longer cords on the tool itself.

I don't do that because I need extension cords for various tools I test, the cords are there, so there's not much point in lengthening the cord on my table saw. Besides, what then happens if I move the table saw closer to the outlet, or further away? Extension cords are temporary, can be replaced easily, and are not any kind of real shop problem that I've ever heard of.

Charlie Self "Giving every man a vote has no more made men wise and free than Christianity has made them good." H. L. Mencken

[Mike Marlow]

Ok - I was just taking a guess. I just assumed that if you had done some electical work you'd have seen the similarities between wiring up a plug on an extension cord and wiring in a duplex outlet, and have held a confidence in shop made cords. Having seen some of your other comments about your uncertainty with some of these things I guess it's just your nature to be a little worried about them... and that's fine by me.

Hey - to each his own, right? You're the only person you have to satisfy in this matter, so it doesn't matter what I think or anyone else.

It's not really - that was just an assumption I made base on the way you made your earlier comments more than anything else. Like I said, I assumed that anyone who has wired up branch circuits would feel very comfortable with something as simple as an extension cord, so I assumed that with your reservations, it was possible you hadn't ever done any amount of electrical work. Though... I might suggest that it really is something of a matter of not trusting your own work.

Hell Brett, if you never become totally confident about your wiring, it's not the end of the world. It's not like it's a big deal. You're the only one affected by it so it's all just a matter of what you're comfortable with.