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Subject: Re: Old easy question?
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Date: 01/28/02 at 1:17 PM
Posted by: tom
In Reply to: Re: Old easy question? posted by Russ Kincaid on 01/26/02 at 4:36 PM:
Voltage can either be positive of negative. However whats important to understand is that this positive or negative voltage is in respect to reference. In most cases this reference is ground. As ground being the reference it is considered to be 0V. Thus during the positive half cycle of an AC signal, the "HOT" wire is positive with respect to ground and during the negeative half cycle it is negative with respect to ground. In any circuit there must be atleast two paths for curent, on from the supply and one return to the supply. In house wiring these two paths are the black ("HOT") wire and the white (neutral) wire. The third green wire is ground. The ground wire is tied directly to ground outside of your house. It is important to note that this wire is NOT ment to carry current, it is there only as a ground or 0V reference. The importance of this is because as current flows through a conductor such as wire, not matter how good that conductor is, it WILL drop voltage. This is even more evident in an over current situation. So, if current flows through the neutral wire, which it will, this wire will drop a voltage thus raising its potenial above ground. Therefore the ground wire is there to keep a ground potential on the chassis of any device plugged into that circuit.
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