Basic Home Electrical Question

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Nothing silly about being safe.
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Christopher A. Young
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chassis of our stove and dryer are connected to the neutral. Unless the neutral connection has come loose, it is an almost infinitely better ground than the person touching it; so the toucher gets close to 0v.
In the situation you describe is even safer; a (presumably open) switch or a unused outlet, you could lick the neutral and get nothing; unless the ground bus has come loose, it is absolutely 0v.
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Yes, as long as you are not in contact with a hot line.
In fact, if you are careful not be be grounded you can touch the hot wire without a shock. I don't recommend doing this, but I have changed both switches and outlets while they were live.
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Rich Greenberg Marietta, GA, USA richgr atsign panix.com + 1 770 321 6507
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Yes it may be somewhat confusing. As Einstein (100 years ago last month) said, it's all relative. Try to picture an oscillating wave representing 120VAC. The difference between the top and bottom of the waves is 120 V. Now if we force one side to be grounded the other side must be oscillating between plus 120 V and minus 120 V. But remember there never is more than 120 V relative to ground.
On Navy ships all 120 VAC power has no neutral. Each leg is hot and is 60 VAC relative to ground similar to the way 240 VAC in your house is set up. This is for safety since you will only get a 60 V shock between a hot and ground. We always had to check out test gear we took ships to make sure that the neutral was not connected to ground.
If you really want to be confused try to understand 3 phase power. Ever notice how all high voltage lines are in sets of three. With three phase power the sum of the power supplied to a load is constant so motors and generators run much more smoothly.

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volts negative peak, not 120 Volts. This yields the effective voltage of 120 volts (RMS). RMS voltage is .707 x peak. Peak is 1.414 x RMS.
Bob
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3 Phase is really easy to explain. You put a volt meter across any two wires and you get 277 volts. but across the three is 480. Simple math huh? Then there is power factor . . . . . .
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Any two will get you 480 volts. If wired in the Y configuration and the center is grounded , then you get 277 to ground from any wire.
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Oops, that's right of course. 2 x 277 = 480
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Then there's the whole Y or Delta configuration. Hated those classes in college.
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Polarized plugs are a safety feature, especially with something like a lamp. This connects the "hot" wire to the center connection where the bulb screws in.
When replacing a light bulb, it is possible you could accidentally touch the metal ring while unscrewing the bulb. If the metal ring is connected to neutral (because of the polarized plug), then you will not get shocked.
Also the polarized plug will connect to an appliance on/off switch. So when the appliance is switched off, it is shutting off the hot. So say something like a toaster which has a switch which only disconnects one wire. It is best if the wire the switch is disconnecting is the hot wire! Otherwise hot would be connected to the heating elements even when the toaster was off, and a kid might stick a knife or hand inside the toaster, then be shocked.
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On 22 Oct 2005 16:11:53 -0700, snipped-for-privacy@hotmail.com wrote:

There are actually three conductors in house wiring; hot, neutral, and ground. Only the hot and neutral wires are intended to carry any current. The gound wire is a safety device. It is connected to your cold water pipe, to any exposed metal in powered appliances (hence the three prong plug), and to the earth itself. And, at your main circuit panel, it is connected to the neutral wire. If the wiring is correct and functioning as intended, you should only be able to observe (via a meter) a voltage difference between the hot conductor and *either* the neutral or ground conductors.
These designations, and the way the safety system functions, are completely independent of whether the system is driven with direct current (DC) or alternating current (AC).
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Art Greenberg
artg AT eclipse (remove this) DOT net
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