220v extension cord for Table saw?

[Brett A. Thomas]

To be clear, I'm asking not to lecture, but because my understanding of practical electricity is imperfect, and I want to understand. I get why _you'd_ need to do that, but I don't happen to have manufacturers sending me tools that rotate in and out of my shop on a regular basis. When I put a tool there, it's because (excepting shop reorgs) I expect it to be there until it dies, or I do.

I believe that the logic behind the NEC frowning on permanent extension cords (assuming my memory that they do is correct) is that every time you have a non-hardwired connection, it's possible for it to work loose. If it works loose, you can have arcing, which would be doubly bad if it's in a pile of sawdust in a workshop at the time.

When I redo all my tools 220, I figured I'd need to replace the plugs, anyway, so I'll make the tool cords be the necessary length to not need extension cords. I'd figured this would be safer and neater.

-BAT

[Brett A. Thomas]

Actually it's less a fear of not screwing things in right than of simply not making the right decisions to begin with. I teach myself a lot of things, and I learn by making a lot of mistakes. I've read all I can stand on the subject, and I *think* I know what I'm doing, but I'm not really going to trust it until it works for a long time. Much the same way the second piece of furniture I built was a bed for my son, and it was at least a year before I stopped sitting down on it gingerly.

In fact, in my experience teaching myself things, right now is the _the most dangerous_ time for me - I *think* I know what I'm doing with electricity. That might be a false confidence, though, so I'm extra careful.

-BAT

[J]

Go with twistlocks. If your tools aren't moving around the cord isn't going to work loose. As for sitting in a pile of sawdust, well, one end of the cord is in a socket the same as any other cord so there is no difference in safety there. The other is near the tool. Mine are typically off the ground so it should be OK too.

Tools on mobile bases and extension cords are the way to increase your shop size considerably. Mine is now as big as my garage AND driveway.

We have disproved the safety part. Now tell me how it is neater. You still have a cord going from tool to socket in either case. In the case of extension cords you can roll them up and put them away if you want to. I do. It means the kids can't turn on the machine by accident or even on purpose.

[Mike Marlow]

Ha! You gotta get a job like Charlie's Brett.

Maybe hardwire is the way for you to go. In my shop area tools move around as they're needed. They don't always move to the same spot on the floor, depending on what else is going on there. That's where extension cords come in very handy. If they were stationary, and fixed, I'd hardwire them with no plug at all.

The same could be said of any plug, whether it's a UL listed cord, the plug on the end of a cord hardwired to a table saw, or any other plug in your shop. Where it's a concern for a plug coming loose, twist lock plugs address the concern nicely.

Not really any safer in practical terms and I don't know how much neater either. After all 10 or 20 or whatever feet of electrical cord is still 10 or 20 or whatever feet of electrical cord - no matter if it's one long piece or two smaller ones in the form of an extension cord. But - since it sounds more like you're permanently placing your stuff, why not just hardwire and forget the plugs completely?

Just as a sideline, I have about 25 feet of cord wired to my table saw motor so that I can put it anywhere and hit an outlet. It's really no different than having a 6 foot cord and using an extension cord, but at one point I had to replace my cord and I had some long stuff lying around so I just used it that way. The one and only real disadvantage is that I always have 25 feet of cord to deal with as I move my saw around. Not a big deal at all, but there are down sides to everything.

[Brett A. Thomas]

Well, this is getting into a whole other question, but I'd love feedback on this. My basic plan has been to run a dedicated set of wiring for fixed machines (defining "fixed" to include some stuff that's mobile but plugged in most of the time), and to have panic stops and a lockout box for those circuits. That'll let me lock down the stationary power tools when I leave the shop (in case the kids get in) but still have lights work, batteries charge, etc. Anyone have a good source for those kinds of electrical supplies (lockout boxes, panic buttons, etc)?

-BAT

[dan]

I have - ever since I plugged something into a brand new extension cord and ended up with a whole lot of arcing going on. Scared me half to death as it was one of those "fancy" cords with 3 outlets on the end, and clear plastic so you could see the little neon light in there to show you it was live. The act of plugging in a tool caused one of the parts of the outlet to shift inside the plastic and contact another part. Needless to say I was not amused.

Goofy thing is that this of course was a more expensive cord while I normally get el-cheapo extension cords that I treat almost as disposable. A nick in the insulation and it gets cut in half for use in other projects.

Dan

[dan]

I have - ever since I plugged something into a brand new extension cord and ended up with a whole lot of arcing going on. Scared me half to death as it was one of those "fancy" cords with 3 outlets on the end, and clear plastic so you could see the little neon light in there to show you it was live. The act of plugging in a tool caused one of the parts of the outlet to shift inside the plastic and contact another part. Needless to say I was not amused.

Goofy thing is that this of course was a more expensive cord while I normally get el-cheapo extension cords that I treat almost as disposable. A nick in the insulation and it gets cut in half for use in other projects.

Dan

[Robert Galloway]

hey, guys. No offence intended, none taken.

bob g.

Brett A. Thomas wrote:

[Mike Marlow]

Well, the simplest lockout box is your subpanel. Throw the breakers when you're done for the day and secure the subpanel in any way you're comfortable with. You should be able to find a number of commercial electrical supply houses near where you live that would have just about anything you'd want to put in. You can get really carried away with this stuff and sometimes you have to step back and say - hey, this is just a hobby shop - do I really need this or that or the other thing, or is a simpler method a better approach. Personal preference will prevail.

[Brett A. Thomas]

Yeah, that's usually a danger for me. :) But I'm also a bit of a safety freak. I'm sure the price tags will dictate a lot of my design, anyway. At the very least, I'd really like to be able to actually *lock out* the big tools so I don't have to worry about the kids at all. That'll be very popular with SWMBO.

-BAT

[Charlie Self]

Brett Thomas notes:

Hard wire 'em and use switch boxes with levers that allow a padlock. If that doesn't keep the kids out, nothing will.

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 Bonomi]

IF you're putting in a sub-panel, You can put in a 'manual disconnect' _upstream_ of the panel. These are readily available at the BORG, as well as any electrical supply house. For _not_ a whole lot of money.

Obviously, if you go this route, you run the circuits for the lighting directly from the main panel. You do _not_ want the lock-out to disable the lighting._

'panic buttons' are a whole nother story. These require a 'contactor' (the name for a 'really heavy-duty relay', and some trivial control circuitry that holds the contactor engaged, until a panic button is pushed.

Buying this kind of stuff new *is* generally price-prohibitive. However, on the surplus market -- e.g. -- you can find appropriate heavy-duty components for not a whole lot of money. I haven't looked, but I wouldn't be surprised if they even have the 'big red button' panic buttons.

[Brett A. Thomas]

Thanks for the link. I'm sure whenever I get it all done (or decide it's not worth the effort & cost) I'll post pics...

-BAT

[sandman]

Again, a very informative thread.

One thing which hasn't been mentioned, is the importance of strain-relieves. When using a twist-lock plug, the amount of pull on a 'tripped-over' wire can be enough to break away the stranded wires from the attachment screws. Make sure that the strain relief is suited for size of the wire chosen. Sometimes people think they need to go to heavier gauge wire when the voltage doubles, while in fact the opposite is true.

my 2 cents worth ($33.00 Canadian)