my amp just zapped me

Discussion in 'The Workbench' started by buzz, Jul 12, 2010.

  1. Kunnz

    Kunnz Active Member

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    New York city residential premises have two phases coming in whereas commercial/industrial would have a three phase feed both 120v and 277v, but in reality the voltage varies depending where you are.

    Example say in a residential location black and red each carry about 116/115v, each phase is 120 degrees out with each other. With appliances like cookers and AC’s both legs are wired in a delta configuration that amounts to about 200V. Take a reading of one of the phases and multiply it by SQ root of 3 or put your meter across any two phases for an accurate measurement.

    I don't know if you have a 220v single phase feed in your location as the system changes from county to county or state to state but thats how its done if you require more I squared R and you have access to two or three phases.

    In the UK/Ireland only one phase fed to residential premises and that’s supposed to be on average 230v. I have measured it as low as 214v and as high as 248v in the space of a day at my last address. No point biasing my amp at that place eh. I called the electricity supplier and they sent a guy out to check the mains but he hadn’t a clue what he was doing, I don't even know if he was even an electrician as he looked too scruffy.

    I don't recommend pulling the plug out from the wall either to switch anything off as there is usually an arch flash but I've done it loads of times in a hurry.

    BTW I once had my old electric meter rigged with an inductor to turn the wheel backwards whenever I wanted. One time I wound it back so far I must have been in about 1000 bucks worth of credit. Knowing that the meter reading man was coming at the end of the month I had every applience in the house running flat out to get back into the red.
    In the coming winter I intend to jumper wire the meter completely with a piece of #4 wire as my house is all electric heated.

    :wave:
     
  2. MajorNut1967

    MajorNut1967 New Member

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    How did this go from, “I got zapped by my amp!” to discussing Single phase, two phase and three phase?

    So it is true Niagara Falls power is two phase?
     
  3. Wilder Amplification

    Wilder Amplification New Member

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    All US power is technically two phase if you look at it from the standpoint of 120VAC. However they typically rate it for the full winding of the transformer so it's more commonly known as 240VAC single phase.
     
  4. TwinACStacks

    TwinACStacks New Member

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    :) What's a Breaker? I LIVE WIRE EVERYTHING.

    Love, Stumpy the Electrician
     
  5. buzz

    buzz Active Member

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    just to clarify.....guitar was unplugged, standby was on, power switch then tuned off. 'still plugged in' refered to the mains lead still being in the back of the amp.....and i wasnt stood in a bath!!!!
     
  6. Iron Mang

    Iron Mang New Member

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    Ah thats not correct Mr. Wilder! Two-phase electrical power was an early polyphase alternating current electric power distribution system. Two circuits were used, with voltage phases differing by 90 degrees. Usually circuits used four wires, two for each phase. Less frequently, three wires were used, with a common wire with a larger-diameter conductor.

    Three-wire, 120/240 volt single phase power used in the USA and Canada is sometimes incorrectly called "two-phase". The proper term is split phase or 3-wire single-phase. This is what you are thinking, but its not "two phase"!
     
  7. Wilder Amplification

    Wilder Amplification New Member

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    Hence the "technically" in my statement. You "technically" have two feeds of 120VAC that are of opposite phase relative to the neutral center tap.
     
  8. PaoloJM

    PaoloJM Well-Known Member

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  9. Iron Mang

    Iron Mang New Member

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    No thats not "two phase" electricity. As I said before "Two circuits were used, with voltage phases differing by 90 degrees. Usually circuits used four wires, two for each phase." Do you have four wires coming into your house? If you do then its two phase or if you have a ganged neutral conductor that has twice the current carrying capacity of the the other two wires, that it is two phase power.

    Is the offset 90deg or 180deg on your power?
     
  10. MajorNut1967

    MajorNut1967 New Member

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    The answer to this question will tell LOL!
     
  11. PaoloJM

    PaoloJM Well-Known Member

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    Yes, but we already know the answer, don't we? :)
     
  12. Wilder Amplification

    Wilder Amplification New Member

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    Wow aren't we all about the fucking semantics and textbook definitions today. You guys got anything better to do than attempt to play "cat & mouse" based on semantical errors just because you have a personal issue with a certain tech?

    I requote my original post -

    Meaning that DEPENDING ON HOW YOU LOOK AT IT (it's all relative) it CAN BE SEEN AS two phase 120VAC since you do in fact have two opposite phases of 120VAC relative to the neutral center tap. However, that is not what the text books call it because it's NOT two separate circuits AND they typically look at the full winding which is in fact single phase 240VAC. I never said that the text books refer to it as that nor did I claim that we ever call it that. I simply stated that you CAN look at it that way.
     
  13. Iron Mang

    Iron Mang New Member

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    It's not even worth posting anymore with that.
     
  14. buzz

    buzz Active Member

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    mods...can this thread be locked....my brain is starting to tingle more than my electrocuted fingers!!!!!!!
     
  15. Wilder Amplification

    Wilder Amplification New Member

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    Exactly. ;)
     
  16. Kunnz

    Kunnz Active Member

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    Ok, Ok, Fuck the txt books they are no good anyhow, :naughty:

    Here's what I would like to know and maybe Lane can come in on this as NYC could be different or has changed since I have been there.

    When I lived in NY City the supply to the house was two 120v phases from a 3 phase source, each phase being 120 degrees out of phase with each other respectively.

    There was NO two 120v phases from a center tapped 240v transformer.

    The two phases where delta'd and the result is 208v. Why?
    Because from a 3 phase source when any two conductors are connected together you multipy one phase by the SQ root of three; 208/SQR 3 = 120.

    So it was always 208v in my experience and you's are missing the point and it needs to be understood as my cat is has a mohican listening to you guys.

    :lol:
     
  17. Lane Sparber

    Lane Sparber Well-Known Member VIP Member

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    I BELIEVE that we are powered by two 120v phases from 3 phase source outlined above, and that nothing has changed. I have to admit that this made me curious, so I called Con Ed and was told that info was classified(!). I don't know if they misunderstood me or are just SUPER paranoid of terror threats or what, but that's as far as I got. Industrial/residential power distribution methods are certainly NOT my forte. Sorry I can not supply better info.

    -Lane
     
  18. MM54

    MM54 Well-Known Member

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    And no matter how the electric gets there, and however out of phase any of it is, it still hurts like hell.
     
  19. Wilder Amplification

    Wilder Amplification New Member

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    Fixed :D
     
  20. MM54

    MM54 Well-Known Member

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