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Posted: 12/21/2003 3:47:38 PM EDT
What in the flaming hell is so important about polarized plugs?  Twice in the year and a half I've been in my home, I've had to take a dremel to the prongs on a night light, so that it doesn't block a doorjamb or towl bar or some other dippy thing that wouldn't have been a problem if the wrong prong wasn't on the wrong side.

Does this really matter for something as insignificant as a night light?  Is this something that should only matter for high draw devices or sensitive electronics?  Do I risk burning down my building because I ground down that stupid prong?

Anyone?  Bueller?  Bueller?
Link Posted: 12/21/2003 4:00:57 PM EDT
The "wide" side of the plug is "neutral" (ground, like third "hole").

If enclosure of your item has any exposed metal/screws on it, and you put the plug in backwards (after modifying the plug), when you touch the metal surface, you are now a "short path to ground" and will feel anything from a tingle to a heart attack, depending on how moist your skin is, what shoes you are wearing, surface you are standing on, etc, etc, etc. (ESPECIALLY IN BATHROOM or other areas where alot of water is...  like on your electic shaver/ wife's "equipment)

Best advice:  Upgrade your wiring/house/outlets.  If all of your outlets are not the "3 prong", and do not even have the "wide side"  / "narrow side", that would put you in the timespan when they used aluminum for the wiring (fire hazard).
Link Posted: 12/21/2003 4:14:41 PM EDT
Does this really matter for something as insignificant as a night light?
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If one of your kids sticks his finger in the bulb socket, chances are good that he'll only touch the large threaded contact, not the small center contact. If the night light is polarized, that threaded contact is ALWAYS the neutral ("cold") side, which won't shock him. However, on an unpolarized plug, he has a 50/50 chance of gettting zapped if he touches either contact.

Most polarized appliances are designed this way Ð if something happens where one of the two power conductors should accidentally come in contact with a human, a polarized plug greatly increases the chances that it will the the neutral conductor. It's an additional safety net Ð not perfect, but definitely worthwhile.

(Interestingly, some appliances are designed so that there is exactly the same chance of either conductor coming in contact with a human.  Generally, these appliances don't have polarized plugs.)
Link Posted: 12/21/2003 4:49:59 PM EDT
Turn your electric outlets over
Link Posted: 12/21/2003 5:48:06 PM EDT
OK... now this is starting to make a little more sense.  The building is new enough to have copper wiring and polarized 3-prong outlets everywhere, so that's not a concern.  I guess my understanding of AC was incorrect, since I thought that both sides were alternating hot/cold, with ground remaining constant.  

The only things I've done this to are  two cheap night lights with no exposed metal in the casing, and there's no kids to be sticking their fingers in the sockets, so there's apparent danger looming.

However, with this new understanding of how polarized plugs work, I think I'll start finding more productive uses for the dremel.  [BD]  Besides, one of my "back burner" projects involves pulling a lot of outlets out and replacing them, so then would be a good time to just flip the damn things over.

Good info guys, thanks!
Link Posted: 12/21/2003 6:16:10 PM EDT
These wouldn't happen to be the outlets that are controlled by the light switches are they?  These are turned upside down so that you know which outlets are controlled by the switches so that you don't plug anything vital in them.

The alternating in AC takes place with the voltage, not between the wires.

Link Posted: 12/21/2003 6:23:35 PM EDT
Originally Posted By serrada:
These wouldn't happen to be the outlets that are controlled by the light switches are they?  These are turned upside down so that you know which outlets are controlled by the switches so that you don't plug anything vital in them.

The alternating in AC takes place with the voltage, not between the wires.

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ah-HA!  Another thing that I didn't know.  Nearly every outlet in this damn place is wired that way.  Reason being that in every room, the switch controls one plug on the outlet, but the other plug is constantly hot.  It's made things a bit of a pain in the ass around here, and I'd like it if only one outlet in the room was set up that way.  Now I know the significance of that.  Thanks!
Link Posted: 12/21/2003 6:23:43 PM EDT
Red and Black wires carry the juice. The white wire is "neutral" or "return". The white wire is electrically the same as ground, but are needed to effectively carry the return current back to the distribution panel.

Red and Black both have 115~125 Volts AC on them, but out of phase. Thus, when voltage is taken across the red AND black, you get 240VAC. In this case, BOTH wires are hot, as you thought about the typical outlet. Some outlets are like this (window AC), but not too many. Dryers use both 240 and 115, so it utilizes the red, black, and white, and should also have a 4th conductor, the ground, which ties to the frame or exterior of the appliance.

[:)]
Link Posted: 12/21/2003 6:48:16 PM EDT
Originally Posted By wsmc667:
Red and Black wires carry the juice. The white wire is "neutral" or "return". The white wire is electrically the same as ground, but are needed to effectively carry the return current back to the distribution panel.

[:)]
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Actually, according to code, GREEN must be GROUND, WHITE must be NEUTRAL and HOT can be any other color (Black, Red, Blue, Brown, Pink Etc....) So even though 80-90% of the houses have the color codes you stated, I have seen others.

Also in the day of computer driven appliances, the wiring has to be correct or they dont work. I have had a few dishwashers that were funky because the house wiring was backwards.
Link Posted: 12/21/2003 6:57:47 PM EDT
Removing the ground prong from a plug is dangerous for this reason:

The grounding prong and its conductor offer a path to ground for a short.  For instance, if the hot wire in the night light (or anything else) has its insulation cut, and this constantly hot wire touches the metal light fixture, the fixture will become hot, but it probably won't trip the breaker; there's no load and no path to ground.  Then you or someone in your family touches the fixture, the current travels through you to ground and BINGO!  You are energized - part of the circuit.  Now if you had the grounding prong attached to the grounding conductor, which should be attached to the appliance,  this short current would've traveled through the green wire back to the panel and to ground.    The current would've kept increasing, as the resistance to ground is always very low (at least if everything is properly installed), and the breaker should've tripped.  This probably would've happened within less the 0.25 sec(depends on the breaker).

Unless the appliance is on a GFCI - that works a little differently.

That's "what in the flaming hell is so important."

So - I'd suggest, as a little Holiday safety item, to go to Home Depot and buy a replacement plug. [:D]

Link Posted: 12/21/2003 7:00:57 PM EDT
Don't rely on colors guys...

I've seen a house where the electrical connections were wired dangerously and could easily catch fire... all wires were BLACK! I have seen many wiring problems on old houses.
Link Posted: 12/21/2003 7:04:11 PM EDT
And about wire colors:

I don't work residential(YUK), but commercial.  But in houses, it's legal to use the neutral in Romex as a return from the switch.  So make sure you turn off the breaker before working on stuff.

Also, different cities us different colors.  Here in San Antonio, we use purple brown yellow for high voltage, and black red blue for low in commercial bldgs.  Orange usually is the high leg.  I worked at USAA for the last year, and they wanted to use purple brown orange.  In Austin, they use IIRC red black blue.  I'm talking 3 phase panels here.

Anyway, just be careful.  120v kills more people.  The voltage is low, it "hooks you up" and you can't get off it.

Link Posted: 12/21/2003 7:37:23 PM EDT
Remember,  There is 115-120 volts in a typical houshold outlet with 15-20 amps.  That is 15,000 - 20,000 milliamps.  It take as little as 60 milliamps to KILL you.

A GFCI is your best defence.  It measures the diffrence between the current from the hot to the nuetral.  If there is a diffrence of .005 amp between the two reading it trip the Interrupter.

Never trust that a circuit breaker will save you life!!!


Here's how it may work in your house.. Suppose a bare wire inside an appliance touches the metal case. The case is then charged with electricity. If you touch the appliance with one hand while the other hand is touching a grounded metal object, like a water faucet, you will receive a shock. If the appliance is plugged into an outlet protected by a GFCI, the power will be shut off before a fatal shock would occur.
Link Posted: 12/21/2003 7:44:31 PM EDT
Originally Posted By brasspile:
... when you touch the metal surface, you are now a "short path to ground" and will feel anything from a tingle to a heart attack, ...
View Quote

Been there, done that.

Got bit a few years ago by the outside of a metal table lamp!!
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