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  1. J

    Selling Power PE Exam Materials

    All purchased withing the last 9 months, some purchased within the last 2, so they are the latest editions. All in very good shape, some unused. Msg for details. Study Material: 1. Electrical Engineer's Guide to Passing The Power PE Exam by A. S. Graffeo, P.E. 2. The entire PPI2PASS Power...
  2. J

    NCEES Problem #136

    In this problem about Voltage Drop, they give you impedance and current and ask to solve for voltage drop using the below equation which exists in the handbook My question, why is it wrong to use ohm's law to calculate voltage drop in this situation? They've given you Z and |I|. If I plug in...
  3. J

    Symmetrical Components Question

    In question below, can someone explain why Vpos does not equal Ipos x Zpos bur rather Ipos x (Zneg + Zzero)? Also are Vb and Vc switched, per the standard symmetrical component matrix?
  4. J

    NEC Code: Transformer Overcurrent Protection

    When selecting over-current protection for a transformer, the protection tables in Article 450 are broken up into transformers above 1000V and those up to 1000V. If you have, for example, a 4160V/480V transformer, do you use the "above 1000V" table for the high side and the "up-to-1000V" table...
  5. J

    NCEES Problem 123: Illumination

    I'm quite weak at Illumination in general, but the formulas in the handbook seem pretty straightforward. For the below problem, I would have assumed we use the formula for flux from the handbook: which requires Initial Illumination level as an input. I thought the MMI=50fc we would maybe...
  6. J

    Handbook's Fault Diagrams -> Equations

    Is there an intuitive way to derive equations from the Handbook's Fault Diagrams (Pg 66) without memorizing them. Particularly for the Line-to-Line Fault and Double Line-to-Ground Fault? e.g for L-L faults, that Ia2 = (Ea)/(jX1+jX2)
  7. J

    Does Graffeo's Guid to the Power PE have an errata?

    I've seen mention of this in some forums but the official site is under a weird layout and both has an errata section and doesn't have a link to errata.
  8. J

    Wye-Delta transformer turns ratio question

    Sample Question from PPI's practic problems (Ch.42, # 9) Simplified Question: A 20MVA transformer has 12,500V(wye):4160V(delta) What is the rated primary and secondary current? Book's Answer: Ipri = S/(sqrt(3)*Vline) = (20x10^6)/(sqrt(3)x12,500) = 923.76A Isec = Vpri*Ipri/Vsec =...