Ot: electric tool plugs.

JayinNY · Sep 17, 2012

Can anyone tell me why electric tools, lights ect have a wider slot on one side of the plug than the other? You can only plug them in one way. I take my angle grinder and grind it the same as the other side. What the he'll is the point of that, it works either way? Just a rant I guess...... Lol

JRSutton · Sep 17, 2012

It's an important safety feature.

One side is the HOT wire - the smaller of the two.

Anything with a power switch in it needs to cut the power on the hot side - otherwise the tool would remain energized in a more dangerous way when it's off. It would still shut off - but the motor would still be "hot" or live.

Of course -this assumes the plug was installed correctly.

pete black · Sep 17, 2012

google polarized plugs

retired farmer · Sep 17, 2012

Keeps the positive and negative electricity going in the right direction so you don't get electrocuted. Just more government bull.

RayP(MI) · Sep 17, 2012

They are designed that way so they will only go in one way - that way, the white/black conductors go all the way to the tool. You are aware that the white wire is supposed to be ground potential?

Janicholson · Sep 17, 2012

Outlets are polarized in relation to neutral and Hot. The tools are probably designed with insulation that is good either way, but the manufacturers comply with UL plug regulations. Lamps and other fixtures with removable electrical components need to be manufactured (or repaired) so that the exposed (base threads) are neutral. Jim

JayinNY · Sep 17, 2012

I have older outlets and tools that aren't like that! Must be newer things I guess.

Dalet · Sep 17, 2012

Yea. I usually test my recent wiring by jamming a bread knife in the smaller plug. If I get shocked, I will have to switch the wires around on that outlet...

NCWayne · Sep 17, 2012

If you have ever opened up one of those tools you'd see that the first reply to your post by JR Sutton is correct. With the three prong plugs they would only go in one way, unless you broke off the ground prong. When tools had alot of exposed, or solid metal cases, they had to have a true grounded plug to be safe. When they went to plastic cases, the chance of getting zapped by stray current in the tools metal casing was gone, but they still needed a way to insure the hot wire was broken. By polorizing the plug it assures that when a two prong plug is inserted into the outlet that it too goes in the right way. Properly inserted the switch on the tool actually breakes the positive wire to the tool, as it should, and not the neutral. If something bad were to happen, and the plug was in backwards, the tool would still be electrically 'hot'. As has been discussed on here ad infinitium over the years, you can still complete a 120 volt circuit between a positive wire and pretty much any ground, and by doing so, potentially make you the path the current choses to get there.

Governmental involvment or not, some things are safe, and some aren't. While plugging one in either way might be just fine 99.9999999999% of the time, that .0000000001% of the time it's not could very well kill you.

Phlash in OK · Sep 17, 2012

On older tools,elect skillets' toasters, etc one can get severe elec shock if the plug is reveresed. It happened to me years ago with a 1/2 in drill. It happened to my wife when she was standing in damp grass and had her hand on a travel trailer. In both of these cases the polarity was reversed and what should have been ground was hot. Yes there is a reason one side is wider.

Walt Davies · Sep 17, 2012

I have a collection of very old electric waffle irons you better know what you are doing with then plug one in wrong and the whole outside case is hot. I for one am glad to have polarized plugs.
Walt

Tony in Mass. · Sep 17, 2012

I'd like to try to explain the way it was explained to me years ago, having to do with the brass and silver screws on the side of the boxes, but then, last week I was called a liar and fool for saying I started a tractor in a way that these Einstiens and Edisons say can't be done. So I will have to let you wait until an electrical genius shows up to explain it all properly ... but in a nutshell, the 'truth' about the hardware in your house has changed atleast 4 times since the 1880's, and these plugs are the way to keep you safe in the latest version of scientific truth...

paul · Sep 17, 2012

Missed that conversation, guess it would be poor of me to ask you to repeat an engine stating story that got you yelled at the 1st time.

The nuetral wire is dead when the power switch is off. The hot wire is hot even with the switch off.

It's a while lot better for as little of the device to be powered by the hot wire as possible, so they came up with the polarized plug to try to make it so.

Now some fella comes along and grinds off the fatter spade and defeats the point of all that fancy wiring.....

Might as well use the ground wire interchangably for a neutral wire too.....

Hey, as long as it works, it must be right.....

I'm sure the 2 good electricians here agree with me???????

(All meant in lightheartedness.

1. It would be best if you don't grind off the fat blade - it is a safety feature that keeps you a tad safer by keeping less live power around your hands.

2. Of course neutral and ground wires should be kept seperate & isolated - they serve different purposes and you defeat the point of the ground wire if you bond them more than once.

3. It's real easy to make electricity work; it's real hard to make it work well and safely with backup safety built in when folks keep trying to defeat the safety stuff for some reason. Why does the fat blade bother a person?)

--->Paul

Jon Hagen · Sep 17, 2012

I learned a little ditty years ago to help me wire things . White ( white nuetral wire) and the WIDE blade / slot go together to keep the wiring correct / safe.

PJH · Sep 17, 2012

Years ago - before I quit fooling with electric instruments, I learned the hard way about polorized recepticles. You could be standing in wet grass, playing guitar for a night party, and that darn amplifier would shock the socks off of you. Pull the plug, flip it over, and your troubles were over.

old · Sep 17, 2012

2 or 3 prong?? If 2 that is so in theory you have the correct side of the tool to ground or should I say neutral that way in theory you have the hot side where it should be and the neutral side where it should be if the building is wired the correct way that is

MarkB_MI · Sep 18, 2012

Power tools are required to have either three-prong plugs or to be "double-insulated". I'm pretty sure that the insulation on a double-insulated tool works best if the power polarity is correct. It will still protect you from shock if you plug it into a receptacle with reversed polarity, it just won't protect you as well.

Stephen Newell · Sep 18, 2012

Back in the old days when a manufacturer took pride in their product the polarized plugs weren't so necessary. Do you really want to chance reversing the polarity of a Chinese appliance? The plug protects you when the junk malfunctions.

oliver power · Sep 18, 2012

Just yesterday, we pulled into a job site. Employee plugged our roll former machine into the house recepticle. He touched the machine, jumped back, and yelled "I Just Got Jolted". The trailer, and everything in it was HOT. Simple plug in tester showed wires to be crossed. All this time, employee thought plug in tester was only for checking to see if we had power. Now he knows why it has 3 little lights, and symbols on it. Front porch recepticle tested OK. That's where we pulled power from.

36 Coupe · Sep 18, 2012

Cuts your chance of getting shocked by 50% on older metal tools.You goofed grinding that prong.I have had a few tools that shocked the user.One drill was on a GFI that failed to trip.The metal gear box on your grinder could conduct electricity from a shorted armature to your hand.An altered cord on a contract job can bring a fat fine from OSHA.Now you know.

John T · Sep 18, 2012

As posted polarized plugs (Neutral and Hot only go to their respective slots) are a safety feature. The Neutral is a GrounDED conductor which has a tie to good old mother earth back at the main panel while the Hot has a potential above Neutral and a body shouldnt get between those two potentials !!!!!!!!!!! That can ruin your day and/or cause you to wake up dead!!!!!!

Years ago they made "hot chassis" AC powered radios and the hot wire could be attached to the radios metal case depending on which direction the plug was inserted into the outlet OUCH but many modern electric tools dont have a conductive outer case to prevent shock hazards. Most construction sites also use GFCI protected outlets to further increase safety.

John T

Greenday · Sep 18, 2012

you'll find out when you get a shock some day! lol

John T PS · Sep 18, 2012

I saw perhaps some confusion below, a switch or circuit breaker etc. is supposed to break open the HOT wire NOTTTTTTTTTTTT the Neutral (A GrounDED Conductor). The Hot wire has a potential of 120 VAC with respect to the Neutral and the Neutral is tied to good old mother earth at the transformer and again at the main panel. The Neutral is NOT supposed to be broke open by switches or breakers etc., ONLY the HOT. When switching 240 volt appliances usually BOTH hot wires (240 VAC between them) are opened by a switch even though the device doesnt work if only one were opened.....

Hope this helps

John T

36 Coupe · Sep 18, 2012

Strange statement.Polarity changes 60 times per second on ac.Grounding one side of the AC line cuts the chance of shock by 50%.

36 Coupe · Sep 18, 2012

Plenty of electric stoves disconnect only one side of the oven element.

John T · Sep 18, 2012

Yep they sure do and older stoves only used 2 hots and a ground even though they had some 120 on board THATS A NO NO TODAY HOWEVER

Fun Chat

John T

David G · Sep 18, 2012

The plug will be polarized if there is a shock hazard plugging it in backwards. That is a BAD idea grinding them off.

Ultradog MN · Sep 18, 2012

You should ask forum member Nebraska Cowman this question.
I'm sure he could give you an answer.

PJH · Sep 18, 2012

Jay - I'll bet that the receptical that you're plugging into is an ancient one that is not configured for the modern plugs. If that's the case, it would be easier to change that outdated receptical than it would be to grind off the wide prongs on all of your tools, etc. And that's not even considering the safety issue of reversed polarity.

Paul

Mike (WA) · Sep 18, 2012

Changing out old receptacles can turn into a real nightmare- wire is old and brittle, many times will break off and be too short to hook up a new receptacle. And forget about just poking the wire into the little holes in the back of the modern receptacles- they used BIG wire back in the day.

Better might be to get a plug adapter with big and little slots, and grind its plug side down if you must, so you don't have to grind off the tool's plug and tool will still be properly protected when used with modern receptacles.

36 Coupe · Sep 18, 2012

They used # 14 wire.Its still used on light switch lines.

barnE · Sep 18, 2012

Don't forget the GFCI. Ten bucks may save your life or someone in your family. All other posts also are great. If you ever see someone on their back with smoke coming out of mouth and nose, you sure will remember. Dave

36 Coupe · Sep 19, 2012

A lightning strike on the power line will destroy a GFI.I have found many that failed to test on construction sites.Almost got it from a drill in a wet cellar.Clown used cardboard for insulation around the switch.GFI didnt trip.Open up a bad one and count the parts that could fail.

Ot: electric tool plugs.

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