I stepped on the plug to my bench saw and the third prong broke off. If I use an extension cord to connect the broken plug to a GFCI outlet, is that okay?
Janet
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Replies
Janet,
The third prong you broke off is, presumably, the U shaped ground instead of one of the flat prongs that carry current.
Is it OK? No not really. The saw will start and run, but you have lost part of the safety system that would protect you from a serious electrical shock if there were an electrical malfunction. The GFCI gives you some protection, but not as much as having both the GFCI and a proper ground. Also if the GFCI fails, and apparently they do even if they test properly when you hit the test button, you would have no protection against an electrical shock if some part of the saw's switch or wiring failed.
John White, Shop Manager, Fine Woodworking Magazine
Is it OK? No not really. I agree.. Get a new plug.. 5 dollers us at the most.. Save a life I say!
Its not all that hard to replace the plug on the cord. Every hardware store or big box will have plenty of choices of plugs.
Thank you. I had hoped that a replacement wouldn't be necessary, because my wiring and soldering never looks as neat as they ought. But looks are not as important as safety.Janet
You want a male grounded plug. Be sure it's U L listed. There's a lot of yellow look alike male and female connectors around. (Made in China)
They are not color coded as to which wire goes where.
(they are cra.. junk)
Buy one made in USA (No need to solder)Only need a screwdriver and a wire stripper The insulation is bared back about 3/8" and wire inserted into 3 holes which, by tightening the corrosponding attached screws,clinches onto the wires. The screws are green, For green (ground) wire.
Gold, for black (line) wire.
Silver fow white (Neutral) wire.Steinmetz
Edited 2/20/2006 4:52 pm ET by Steinmetz
Janet, when you are ready to replace the damaged plug....there is a gauge inside the body of the replacement that you choose, use it to strip the insulation from the black, white, and green wires...it may be easier for you if you strip the jacket longer and cut the wires to the correct length....also, one more trick..
...once you strip the insulation, twist the exposed copper wires CCW, the wire is made with a CW twist and your untwisting and twisting in the opposite direction will make the ends a bit stiffer and easier to work with....
Make sure you get your hot and neutral correct as well. Just copy the layout in the original plug.
Personally, I wouldn't operate that saw until I got the plug replaced.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
You won't need to do any soldering. Go to home depot and tell them you need a 3-prong plug with screw-type terminals. They're a snap to install.TFToolfanatic (a.k.a. The man formerly known as "Toolfreak")
Wow, things have changed a lot since the last time I had to solder!Do I need to know anything about wire gauge?
no need to worry about gauge when you are replacing a plug with the same configuration........if your plug has two straight blades and the ground, then a similar looking one will be adequate for the wire size....in your case I 'm guessing you only need a 15A plug
You don't need to do any soldering, just cut off the old plug and put on a new one. The worst you'll have to do is strip the wires and use a screwdriver. The whole thing should cost you less than $5.
Jan, replace the plug, for sure. These other comments are right on. I'd like to add the advice that you buy one of the big plugs, big enough for you to grab when you need to disconnect. You can't yank on the cord anymore.
That's a good idea too, I'd recommend getting one of the plugs with a screw-in collar that holds tight to the cord so that even if you do yank on the cord, it's going so stay in the plug without any damage.
I am gonna post this and weather all the criticizm for my post. While I do not recommend using this tool, I would argue that using this tool with the extension cord to a gfci is not overly dangerous. let me explain my rationale.
A groundfault circuit interuppter is a device that measures for variance of current flow between hot and neutral. if it senses a variance of more than 5 milliamp (i think) it shuts off the power through the plug ("trips"). It does not need a ground wire to tell it to do its job. I believe the National Electric Code still allows GFCI outlets to be put on old 2wire systems (1hot, 1neutral, no ground) as the only way to replace a 2 slotted outlet with a three pronged style. The ground post in this system isnt even used at all.
Anyways I do recommend replacing the plug but just thought I'd post a few thoughts. ok now comes the criticism................
For the most part you are right, there are only a few unlikely scenarios where a GFCI wouldn't supply protection even if there wasn't a functioning ground. The problem is that GFCI's can fail to function, or they can be hooked up improperly, so having a ground gives a second level of protection.John W.Edited 2/27/2006 11:55 am ET by JohnWW
Edited 2/27/2006 11:55 am ET by JohnWW
Just curious why we decided it was the ground pin of a 15A/120V plug with no verification. The plug on my TS is a three-prong 220V locking type.
I recognize other clues (re 15A/120V), too, but I think with electrical advice, verify the type of plug, how it's attached to the cord (molded; screw connectors) to determine whether to cut the cord, or to unscrew the pigtails, and then take the broken plug to get a quality replacement.
Just wondering--I really get a lot out of reading these news groups, and am not trolling. :)
Electrical engineer here..If you tool came with a three wire cord (I assume it is a newer tool). GET A PLUG for it and USE THAT GROUND! Think of it this way.. If the tool did not need a ground wire it would not have a ground wire! Some are double insulated and have no ground wire.. The way manufactures are cutting costs these days you can be sure if DID NOT need that ground they WOULD NOT spent the extra money fo it!Hell, I'll send ya the $5.00 for a new plug!EDIT: Electrical engineer here.. But can't spells..you should be your tool
Edited 2/28/2006 8:19 pm by WillGeorge
It wasnt my intention to say that the plug shouldnt be replaced, quite the contrary. My point was that the upstream gfci if it tested and working properly would do much more to prevent electocution than the third prong. But I agree replace the plug, better safe than stupid...
It's official: I am Hopeless At Wiring. Got one of those no-solder replacement plugs, but was having a devil of a time getting all the little wires *around* the screw (no clearance) and *under* the head of the screw. Finally turned it over to my husband, who connected them in a flash. << sigh >> The odd thing is, when the black wire is connected to the gold screw and the white wire to the silver screw, that leaves the green wire kind of far away from the blue screw. Does this mean the wires and screws are mismatched?Is there a gadget to test if the wiring is correct?Janet
Edited 3/5/2006 3:29 pm ET by jyang949
Janet, if the jacket of the cable and the wires are both cut according to the instructions,or templates... the wires will be of sufficient length....sometimes you can put little doglegs in the wire to allow you to guide them straight into the proper terminal .......but you mention a blue screw??? what brand did you buy???
I went to the local ACE Hardware, which had only one kind of plug--no package, instructions or template. Brand name Cooper, made in Mexico. Yes, the screw for the 3rd prong was blue-ish. There were no holes or clips for the wires.When you face the cut end of the cable, the wires are arranged white, black, green in clockwise order. The jacket of the cable held the wires together so compactly, it seemed the wires were meant to be connected in that order.However, after connecting the black and white wires, the blue screw was on top but the green wire was on the bottom. No big deal to send the green wire up to the blue screw (especially since my husband did it for me!), but it makes me wonder if the plug is now wired incorrectly.Edited 3/5/2006 9:00 pm ET by jyang949
Edited 3/5/2006 9:05 pm ET by jyang949
Think of it this way. If you were connecting the plug to the other end of the wire the order would be reversed and the wires would be straight. What makes the difference? Put the correct wire to the appropriate terminal and you should be all right.
If the tabs on the new plug are different sizes, the hot (black) goes to the brass screw (smaller flat tab), the neutral (white) goes to the silver screw (larger tab) and the ground (green) goes to the blue (usually greenish) screw. It's good that you replaced the plug- if the motor has an internal short, it can send current to the case and if you touch it with a bare hand while you're touching something else that's grounded, the current can go through you on its way to ground. (Path of least resistance, you know)
"I cut this piece four times and it's still too short."
did I mention twisting the bare strands in a CCW direction ? it make them stiffer
if the wires have to wrap around a screw terminal they will be a bit easier to handle if you try that little trick...then, BEFORE you put them under the screw make a hook like a reverse question mark ....so when the screw tightens up the hook will become smaller and make a better connection.and like others have said...you are OK with the connections even if it seems tough to get the green where it needs to be
Edited 3/6/2006 8:39 am by maddog3
j yang, you're sopposed to put the appropiate wire ends into the holes (or clips) NOT around the wires.
The screws are tightened after placing each tip into the hole/clip.Steinmetz.
Finally turned it over to my husband, who connected them in a flash. << sigh >> I bet 'MOM' told ya' husbands 'ARE' good for somethining!
Another power cord question: The cord for the drill press has a plastic case around a small section. The case is only about three inches long and a half-inch wider than the cord.At first I assumed that the plastic case was for protecting that section of cord. Perhaps the cord was assembled in pieces and there was a soldered join under the case? But with a little effort the case slid along the cord, and I could see that the cord was one continuous cable.What is the purpose of the plastic case, which is marked "Do not remove"?Janet
the purpose is to prevent the power cord from being damaged at the point where it enters the tool. by allowing a larger loop to form in the cord .
but it sounds like yours may be damaged too, or not re-installed correctly, since it is not supposed to slide along the cord. One end should be square or have a lip that fits into a molded recess in the tool handle,
...you will have to take the handle apart to check that, and unplug the tool before you do.
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'Wer ist jetzt der Idiot?'
>> the purpose is to prevent the power cord from being damaged
>> at the point where it enters the toolThat's odd. When we got the drill press, the strain-relief sleeve was located a few inches from the plug, not anywhere near the motor. I'm guessing it migrated to the wrong end during shipping.A few days ago I secured the cord so the plug doesn't reach the floor (that way, I can't step on it). It's held up by a U-shaped piece of wire between the plug and the strain-relief sleeve. I hammered the wire into the table but left space around the cord; the plug and sleeve keep the cord from sliding much.Now that the cord can't move much, is strain relief still necessary at the motor end?.Janet
I should have checked the drill press before my last posting. The cables coming out of the motor housing appear to have strain-relief sleeves on them. Only a half-inch is showing.So the one near the plug was meant to be there, for some reason.Janet
Janet,
strain reliefs like yours can only work if they are firmly attached on either end. usually at the motor, and you have changed the plug, so the attachment is not there!
if it slides along the cord, it serves no purpose....Inspect the little sleeve on the motor , my guess is that strain relief was longer and now is in two pieces ... if so it cannot be fixed, only replaced....rest assured, they do break , but earlier you also said something about raising the cord off the floor ...to pervent this from happening again .you must also peek inside the motor now to be certain the wires and connections are OK..Tom
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'Wer ist jetzt der Idiot?'
That's called a strain relief and it keeps the wires from being damaged when the cord is pulled to the side. Within reason. Usually, there's a wider ring around end that's inside the motor (or whatever pieec it attaches to) and this keeps it from pulling out. You may be able to find a replacement sleeve but it will require removing the cord and the old one, then sliding the new one over the cord and reconnecting it. Long run- it's worth doing. Short run- it'll work till it arcs through the cut insulation and pops the breaker or fuse.
"I cut this piece four times and it's still too short."
Hope this isn't too late... What I do is cut the cord an inch or so from the plug, then I use the plug as a guide, this way I can see which color wire goes to which prong.
I threw the old one away already! Don't it figure.
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