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  1. C

    High leg delta/high leg heating up and tripping the breaker

    My last measurement showed each leg around 115 amps. Everything was balanced. I'm guessing the excess energy was in the form of heat in the one leg that was heating up.
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    High leg delta/high leg heating up and tripping the breaker

    The voltage was fine but each leg had a little difference in current, not much though. It would run for an hour and then trip. So the only possibility that I can see is that the fault wasn't in direct contact with the can but was so close that just a tiny bit of fault current was leaking through...
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    High leg delta/high leg heating up and tripping the breaker

    The ground fault was just inside of a flex connector that I had no way if seeing. The company I work for didn't have a meg ohmmeter to check the wires so they insisted on changing the breaker to a fused disconnect which I thought was fooling because I knew that the breaker was not the problem...
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    High leg delta/high leg heating up and tripping the breaker

    I found the problem, it was a high resistance ground fault. I found a nick in the wire just inside the flex connector. Thanks for your help anyways
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    High leg delta/high leg heating up and tripping the breaker

    The supply is a delta high leg 3 phase. The high leg is 208 phase to ground, the other two phase are 120 to ground and it's 240 phase to phase. The load was a little off balance. A phase was drawing 105 amps, B phase 115 amps and C phase 120 amps
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    High leg delta/high leg heating up and tripping the breaker

    Ok I have a question that hopefully someone can answer. I'm an electrician and I recently had a service call where a hotel had a 175 amp 3 phase breaker feeding an ac unit with 4 compressors and 2 blowers that kept tripping. I first checked all the compressors and blowers to see if they were...
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    How to find ampacity of 1/2 by 4 copper buss bar

    I tell you why I'm confused, I read 1000/in^2 as 1000 divided by inches squared. I think the NEC would be right to rewrite that so it looks like multiplication
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    How to find ampacity of 1/2 by 4 copper buss bar

    How to find ampacity of 1/2" by 4" copper buss bar I have a question about finding ampacity of buss bar. I have a 1/2" by 4" copper buss bar and the only formula I can find in the NEC is 1000/in^2 but when I use this formula I come up with 500 amps and I'm being told that 1/2" by 4" copper bus...
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    How to find quadratic function

    Forget it. I figured it out. Having brain bubbles today :-)
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    How to find quadratic function

    I'm looking for the function y=ax^2+c with the given points (-3,89) (2,39). Thanks
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    Why is spacetime shown on a 2 dimensional plane?

    I don't have the mathematics down quite yet but one thing I've noticed whenever I watch documentaries about gravity in relativity is that it's always described on a 2 dimensional plane. They show a planet bending space time as if the space time is underneath it but I'm thinking that the space...
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    Systems of equations with many equations, more than 3

    I'm doing quadratics and I broke down some data into 8 systems of equations and I was wondering what the best way to solve this was. Someone online mentioned doing Gaussian Matrix but I don't know what that is. Any suggestions?
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    Arcing - What affects size of arc when switch is opened?

    So then if a main breaker was closed outside of a building feeding equipment inside the building but their individual circuits were open then there would be no arc as that breaker closed? There would be voltage but no current and my understanding is that it will arc
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    Arcing - What affects size of arc when switch is opened?

    When an electrical circuit is opened or closed there is an arc between the terminals/buss that the switch or breaker is connecting or disconnecting and the arc is greater depending on the amount of voltage. My question is, is the arc greater when there is a resistance/load on the circuit? I'm...
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    Open neutral

    Thanks everybody. Thanks turtlemeister that drawing really helped!
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    Open neutral

    In a single circuit I've always understood that a neutral was a return essentially completing the circuit for the current to flow but I know that losing a neutral can cause imbalanced load and burn up equipment, my question is, how is this possible? If I were to open the hot, it would simply...
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    Positive charge

    Thank you
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    Positive charge

    When they dope the semiconductors in transistors, is that a form of chemical reaction?
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    Positive charge

    Sophie I feel like you're being a bit condescending and I'm just trying to learn. That's why I asked the question
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    Positive charge

    I've just recently learned that protons do in fact have a charge, I was wondering if someone could explain this, as far as applying a positive charge, some real world examples. I've always studied current as a flow of electrons, never heard of a flow of protons before and have no idea what it...
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    Copper wire

    If electrons flow on the surface of a wire, why isn't copper coated aluminum wire used in electrical applications instead of solid copper wire? It would be more cost effective
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    Ground fault

    Thanks everybody!
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    Ground fault

    Thank you wirenut that was very informative. One last question if you don't mind. Is the amount of fault current restricted by the size of the wire? I'm guessing yes but just confirming
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    Ground fault

    I thought about it and I understand what you guys are saying but still not understanding why that particular breaker trips and not all the breakers or the main breaker of there is one
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    Ground fault

    I read an article the other day that stated that what happens in a hot to ground is that the ground wire carries the current back to the source where it tied to the neutral (the transformer was the example they used) and then that current was cycled back through to the circuit breaker causing it...
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    Ground fault

    I have a question. When an energized wire contacts a ground wire or goes to ground, I know there's an increase in current and the breaker will trip, but my question is why? Is the energized conductor pulling more electrons from the earth causing it to exceed the breaker rating? Thanks
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