Recent content by GreenNGold

I feel the same way. All I know is that it will be over tomorrow. Good luck all.

Is (2 x 10^-7) ln (GMD/GMR) used when per phase inductance is asked for? And (4 x 10^-7) ln (GMD/GMR) for total inductance?

For problem 19 in exam 5, why is 2 x 10^-2 used rather than 4 x 10^ -7? I have seen two equations for inductance per phase, (2 x 10^-7) ln (GMD/GMR) and (4 x 10^-7) ln (GMD/GMR). Can anyone clarify when each should be used? Thank you.

Has anyone does example 51 on page 128 using the MVA method? If so, what is the MVAsc for the transmission line? I thought we are suppose to use KV^2 / Z to get the MVAsc for cables or transmission lines but when I use (230kv)^2 / 0.19 I get the wrong answer. But if I use the MVA/X I get the...

How is the practice exam in this book? And how long would you say it would take to go through the entire book? My plan was to use this book as a final overall review the week before the test. I've done most the practice exams (CI, spin ups, NCEES, PPI) but I felt this book covers most topics...

Can someone explain to me how this problem is different from PPI 1-67? Here is the PPI problem: A distribution system is designed as a 3ph, 4 wire, neutral-grounded system. The phase-to-phase voltage is 12.8kV. The complex load power is expected to be 150+j75 kVA between phase A and neutral and...

I had tried to do a search and must of missed those. Thanks, I appreciate it. The 516 I have is a different problem though. It shows a thyristor circuit? Anyone have that problem? I am going to have to do more research on the wattmeter method. I thought I had it down but that 30 degrees has me...

I had a few questions on the NCEES exam and could not find them on this board. Hope someone can help. 1. NCEES Question 128. Does anyone have a good article about the volts/hertz ratio? Or can someone explain the relationship between the two and what happens when volts is increased and hertz is...

I've also had this question. My coworkers told me this but all have said they have not seen this is writing anywhere. This is what I found about reference materials: Reference materials The PE exam is an open-book exam. You are allowed to bring reference materials to the exam, provided they...

For problem 2-4, isn't it a buck because of the location of the dots? I don't think I completely understand what you mean by the buck transformer being wider than the boost. I always thought step-up and boost were the same and step-down and buck were the same but the answer for this problem is...

You are correct. Silly mistake on my part. Thanks.

I have another question for this problem. The primary current is 13.89A ( 300 kVA / (1.73 * 12470)). Since there is primary and secondary protection, 13.89 * 2.5 = 34.725A. Are we allowed to round up to 35A (which is what is shown as the answer), or would you round down to the lower standard...

That is the correct answer and what I got also. But they are saying the S1 = 7<38.7 kVA and S2 = 9<-49.5 kVA. These are the numbers I got: For motor 1: P1 = 5.46kW, Q1 = -4.38kVAR, and S1 = 7<-38.7 kVA For motor 2: P2 = 5.85kW, Q2 = +6.84kVAR, and S2 = 9<+38.7 kVA A lagging...

I had a question about the solution for complex imaginary exam 2, problem 28. Question states: A 3ph, 208V bus has 2 motors contacted to it. The first motor is a 7kVA sync motor with a leading pf of 0.78. The second motor is a 9kVA squirrel-cage motor with a lagging pf of 0.65. What is the...

I had a few questions: 1) Spin Ups Problem 1-80: When a generator is overloaded, the frequency will drop...but when will a generator trip offline? 2) Spin Ups Problem 2-4: Can anyone help explain how to differentiate between buck and boost autotransformers? 3) Spin Ups Problem 2-15: Are the...