ac hotwire question?

Discussion in 'General Electronics Chat' started by t wolf, Dec 19, 2012.

  1. t wolf

    Thread Starter New Member

    Dec 19, 2012
    iam just a hobbyist concerning electricity,my question is if ac current
    represents two opposite polarities alternating back and forth between
    two terminals or contacts (from a generator)which represents a potential difference (voltage)then is the hot wire that comes into a house actually
    a cable with two wires inside of it,always at opposite polarities ?or is this
    just one wire that pulsates current back and forth?

    and lets pretend this is a ac circuit with no earth ground,would the neutral
    wire represent the ground point after the current passed through a node
    and back to the generator?

    and if this ground point is then grounded to earth then does the need for
    this neutral wire to be reconnected back to the generator necessary?

    why?,because if you grab a bare hot wire and you touch the earth ground in any way you complete a circuit,what does that have to do with
    a ground point wire being attached back to the power source
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Generally, two wires go to your house that are "hot". A third will be "ground" or Neutral. In the US, the voltage across the two hot wires will be 240 volts. The electrician will drive a ground rod near your service entrance - this becomes the neutral wire. The neutral wire in the breaker box is actually connected to the ground wire (look closely without getting zapped).

    Each "hot" wire becomes 120 relative to ground. Most circuit boxes are aranged so every other breaker uses alternate hot wires. If a 220V circuit is needed, the breaker simply supplies from both hot wires instead of a hot and a ground and is two breaker positions wide (tall).

    Each hot wire does alternate between 169v above and 169V below ground in a sine wave - 120 V Root Mean Square according to engineers = (169+169)/(2*pi)

    See other posts about earth ground (an infinite sink or source of electrons) to answer your last question. The ground wire is attached to earth, so current will flow through you if you are attached to earth too. Note that birds on a wire are relatively safe - until they touch a wet tree or pole that can ground them while they are touching wire with broken or cracked insulation.