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  1. Fisherman199

    Help Needed With Power Calculations

    Please post these calculations. Conservation of energy will always hold. As far as a basis for feasible power generation is concerned, there's much more to consider than just power input and received output. One must consider the type of load; current and projected markets; load growth...
  2. Fisherman199

    How to create a mini generator that will charge my phone?

    The magnetic circuit is the main intrigue and should command most of your care and attention. Good material will go a long way to ensuring the best results. 1.) High quality, un-laminated, purified copper. 2.) Cold-roled, grain-oriented, silicon steel (CRGOS) is the typical core material for...
  3. Fisherman199

    PCB traces are overheating (due to eddy currents ?)

    Trace length matters here, even at the lower frequency. You're certain there's not more than 26A in consumption? You've measured this?
  4. Fisherman199

    Power lines connecting to the ground

    Fault impedance can vary from nearly zero to effectively infinite (open circuit). When engineers examine fault characteristics of a power system one set of figures will represent the fault duty of the system itself (the fault level the system will provide given the lowest impedance path back to...
  5. Fisherman199

    Harmonics in Power Systems

    I've done this twice thus far. I've got data spanning about 70 days. There was no blink/loss/magic within that time frame. The day after I go get the meter to look at the records they have another incident. Same time as all the others, about 11:02
  6. Fisherman199

    Harmonics in Power Systems

    Could you clarify what you mean by power quality study? How broad are we talking? Investigation of the whole feeder? I've installed a power quality meter (here) and other than Current THD things were found to be within tolerances.
  7. Fisherman199

    Harmonics in Power Systems

    Yes, I thought of needing to add a little schematic last night. I drew one out some time ago. I'll add that below. A current THD averaging around 25% isn't bad? That's what I meant by "harmonic issues." A poor choice of words. The faulted instances were on the low-voltage side of the...
  8. Fisherman199

    Harmonics in Power Systems

    Seeking the guidance of the Physics forums gurus, I was told this would be a good question to contribute to the community. Perhaps it will lead to an in-depth discussion of harmonics: Their creation, implications to power quality, and how to mitigate them. I've been looking at some power...
  9. Fisherman199

    Induction motors

    These questions you're asking are too broad and should be answered through your own study. It's best to come to PF with specific questions after having studied the material. That being said, magnetic field frequency is a result of the current frequency and cannot be decreased nor increased...
  10. Fisherman199

    What is the resistance of a wire if its diameter is doubled?

    I does in fact mention the length. It states the volume of the putty remains constant as the diameter is increased by twice. For that to be true, the length must also change. Remember that resistance is approximated from resistivity and is inversely proportional to the cross-sectional area of...
  11. Fisherman199

    Transmission Line Transposition - Conceptual Question

    The location matters because the mutual inductance and capacitance changes with regard to the orientation of the conductors in space (or in the ground). The mutual inductance of three parallel conductors is different than the mutual inductance of 3 conductors oriented equilaterally. By this...
  12. Fisherman199

    How to understand the Rating of this transformer

    The Maximum continuous AC Power rating: 7.5kVA Primary Voltage: 460VAC Secondary Voltage: 230 L-L; 133 L-N Can be tapped to provide either: 105.0%, 100.0%, or 95.0% of primary nominal voltage. Winding Structure: Delta/G-Wye Percent Impedance at 170 C (normal operating temperature): 3.3%...
  13. Fisherman199

    Alternating energy

    Very nice. I've read all of your insights with great interest. Thank you for taking the time to write them. I'd not read B Level explanation of conduction thread. It went off-rails about as quickly as one would expect. Language can only take you so far. Pictures are the key, I think. They are...
  14. Fisherman199

    Alternating energy

    Electrons are not tiny packet of energy that deliver power. They will not move quickly at any voltage level used in the power system. You confuse propagation of an electromagnetic wave (which is electricity) with drift velocity of charges. EMag waves travel at a goodly portion of the speed of...
  15. Fisherman199

    AC Mains Power conditioner question

    I think you need to have a word with your provider. Problems like this should not exist if you're in a developed region. There are UPS/Generator subsystems where the UPS produces a sine-wave until the generator can have time to spin-up. These are expensive. Beyond that, there is very little you...
  16. Fisherman199

    The Potential of Earth Ground

    This is precisely the case. Since it's a topic of particular interest as of late, I've mentioned in passing to some piers the complexity of grounding throughout power systems and they looked at me as if I were crazy. The subject was always side-stepped in college as well; seen as a matter of...
  17. Fisherman199

    The Potential of Earth Ground

    Would it be fair to say frame of reference is important when discussing grounding? Generally, when I say "ground" I mean a wire somewhere with negligible resistance returning to the source. When I say "earth ground" I mean a metal rod stuck in the ground somewhere with non-negligible resistance...
  18. Fisherman199

    The Potential of Earth Ground

    The GE book is the real deal. Wealth of knowledge about a very complicated subject. It's almost as complicated as discussing grounding. ;)
  19. Fisherman199

    The Potential of Earth Ground

    Here's an interesting thing relating likelihood of ventricular fibrillation to the time and magnitude of electric current exposure.
  20. Fisherman199

    The Potential of Earth Ground

    If there is no potential difference then there's no "shock", I agree. This does not necessarily mean if two things are grounded you're safe. Any voltage applied to earth is going to create a gradient in the soil. When there's a voltage gradient there's a risk of step-potential. By my research as...
  21. Fisherman199

    The Potential of Earth Ground

    Right. Perhaps I wasn't clear. I'm not saying earth is conducting to the source. That's the neutral conductor's job, if there is one. My point is that many electricians and lineman I talk to are convinced that, once something touches earth reference, it becomes safe. That's a deadly...
  22. Fisherman199

    The Potential of Earth Ground

    I wouldn't say the article is totally wrong, but it makes many statements that are false to my mind. For instance: This seems to say earth is both a source and a sink for charge. It isn't. Depending on how you look at the system it may or may not be electrically neutral. Relative to power...
  23. Fisherman199

    The Potential of Earth Ground

    It sounds to me like he needs that credit hour of the IEEE Green Book Jim was talking about.
  24. Fisherman199

    The Potential of Earth Ground

    Agreed, but I find many articles saying things along these lines. People have forgotten Kirchhoff's work.
  25. Fisherman199

    The Potential of Earth Ground

    Here's an interesting read. I wonder what he thinks about the Green Book? He seems to be saying earth ground is a source and sink of charge. http://www.gohz.com/why-current-flows-to-ground-earth-without-closed-path
  26. Fisherman199

    The Potential of Earth Ground

    Grounding is one of the most interesting electrical subjects, I think. The mystery of it all makes it so. I regret not having spent more time with the subject when I was in college and worked around several substation designers. I just got an old version of an IEEE Green book in the mail. I'm...
  27. Fisherman199

    Mensa IQ Test

    Whatever IQ measures I'm undecided as to its utility in life. If having a high IQ gives you confidence to go out, challenge yourself and learn, then by all means, make it the central figure of your identity. It'll be to your benefit. If you can push yourself without that drive, I don't think...
  28. Fisherman199

    Understanding magnetic balance in AC induction motors

    <Moderator edit> Now then, your question relates to something I haven't been able to find much research on, mainly because even most sleeved bearing motors don't hunt for the center very long. If there is a lot of "magnetic play," it may be something as simple as spacers being out of place in...
  29. Fisherman199

    Fisherman From Southern US

    Oh yes :D I have read them with extreme interest multiple times. I also enjoy reading your posts. :smile:
  30. Fisherman199

    Fisherman From Southern US

    Thank you. I've read many of your posts. Extraordinary insight. I have many questions.
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