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Thread: Very Basic Questions about Electricity Supply

  1. #1 Very Basic Questions about Electricity Supply 
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    Hi everyone,

    I have just started getting into amateur radio and am learning a bit of basic electrical theory.

    I am currently confused about how electricity supply works in our households.

    My understanding is that fuel is burned, this energy powers a generator which produces an A/C current. This current is then carried by power lines to our homes. We plug in an appliance and a current will flow in our, say, washing machine, and make it work.

    What I don't get is where the current flows to after the washing machine has dropped the voltage from the electrical socket. In the introductory textbooks it says a circuit must be closed for current to flow. Is there a return path where the current flows from the neutral wire back to the power station?

    Any help would be great :-)


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    Quote Originally Posted by russell_c_cook View Post
    Hi everyone,

    I have just started getting into amateur radio and am learning a bit of basic electrical theory.

    I am currently confused about how electricity supply works in our households.

    My understanding is that fuel is burned, this energy powers a generator which produces an A/C current. This current is then carried by power lines to our homes. We plug in an appliance and a current will flow in our, say, washing machine, and make it work.

    What I don't get is where the current flows to after the washing machine has dropped the voltage from the electrical socket. In the introductory textbooks it says a circuit must be closed for current to flow. Is there a return path where the current flows from the neutral wire back to the power station?

    Any help would be great :-)
    The return path is the ground.( both the neutral and ground wires hook to ground.) You might be wondering why there is two wires that are essentially the same thing. If you have a device that uses a three prong plug, the ground wire prong is wired to something like a metal chassis or something else that would conduct electricity but shouldn't be connected to the source. This way, if by accident a hot wire touches it, it produces a short along with a current surge that blows the fuse/circuit breaker. (better that than you touching an electrified metal chassis and providing the return path.)


    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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    Quote Originally Posted by russell_c_cook View Post
    What I don't get is where the current flows to after the washing machine has dropped the voltage from the electrical socket. In the introductory textbooks it says a circuit must be closed for current to flow. Is there a return path where the current flows from the neutral wire back to the power station?
    Yes. Neutral is often called the return. In the US, 120 volt appliances draw power from the hot lead and return it via the neutral (or return) lead. 240 volt appliances draw power from one hot wire and return it via the other hot wire. In a "balanced" service connection, almost no current is returned via the neutral; almost all power comes from the two hot lines.
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    Quote Originally Posted by billvon View Post
    Quote Originally Posted by russell_c_cook View Post
    What I don't get is where the current flows to after the washing machine has dropped the voltage from the electrical socket. In the introductory textbooks it says a circuit must be closed for current to flow. Is there a return path where the current flows from the neutral wire back to the power station?
    Yes. Neutral is often called the return. In the US, 120 volt appliances draw power from the hot lead and return it via the neutral (or return) lead. 240 volt appliances draw power from one hot wire and return it via the other hot wire.
    Right. This is because the two hot legs are 180 degrees out of phase. A 120v circuit can use either hot leg and neutral to complete the circuit. Then there is 3-phase which uses three hot legs 120 degrees out of phase.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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    Thanks for info everyone. I also tried watching this video: https://www.youtube.com/watch?v=zLW_7TPf310
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