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I am done studying. Time to pack up my stuff and rest. All, Good luck on the exam Friday. Lets hope for easy problems and no rain.

How are others getting their books into the exam? I am using 2 plastic boxes with covers (it may rain) and a luggage cart.

For load calculations, does one add in 125% for general lighting load due to continuous duty. I looked in Article 220, but cannot find anything about adding 125% for general lighting load. The only thing I found is NEC 210.19 (1) for continuous load for branch circuits, but nothing pointed out...

If a 208v WYE connected ungrounded system gets a ground at phase A. What is the line voltage at phase B? Before the system gets grounded the voltage is 208V. After the system gets the ground, I think it still is 208V. The solution says 360V. What do others think?

This problem is fuse sizing to protect conductors against short circuit and ground faults with a motor in the circuit. The way the answer is given in the book is not to consider the ampacity of the conductors when a motor is in the circuit since the conductors are protected against overload by...

In a Delta - WYE or WYE - Delta Transformer does the High to Low or Low to High factor in when determining whether to add or subtract 30 degrees. Below is how I see things. I am not sure if I should be factoring in whether a transformer is going from low to high or high to low when determining...

1. Are the two equations mentioned in NEC Table 9 note 2 equivalent for effective Z. Z = R cos () + X cos () and Z = R x PF + X Sin[arccos(PF)] They appear the same to me, but if they different when do you use a specific equation instead of the other. 2. When using the above equations as...

I have run across two different formula's for ripple factor, not sure which is correct. Formula 1: which I think is correct: r = (Vrms/Vavg) X 100 Formula 2: I stumbled across in the Complex Imaginary stuff exam #2 prob 35 r = (sqrt((Vrms/Vavg)-1)) X 100 What do others think is correct?

If there were 4 conduits (A,B,C,D) spaced as: A <---- x ----> B<---- y ----> C <----- z ------> D What is the Geometric Mean Distance of the 4 conduits? Answer 1: ((x)(x+y)(x+y+z)(y)(y+z)(z)) ^ (1/4) or Answer 2: ((x)(y)(z)) ^(1/3) I think the answer is the one...

This is 3 phase problem. If there is a transformer with the high side (15KV) delta and low side (6.6KV) WYE. The current is 62.7 on the high side, what is the current on the low side? My thought process is multiply the current (62.7) by (15/6.6) and divide by sqrt3 due to going from WYE to...

According to the NEC 430.6 (A) (1), when will I use Nameplate Full Load Current value instead of Table 430.250 value? If I do not meet the speed or torque requirements in NEC 430.6 (A)(1) and my name plate current is less than table value, I use Table Value. If name plate current is greater than...

For this reference I had just printed out what was on Wikipedia and included it with my reference notes. I figured all I had to do was lookup the device number and answer some questions, not much more appeared to be needed. I just finished doing a sample problem that includes a letter "a"...

I notice the reference books that I have are a little light on battery technology. There seems to be battery type questions on the sample exams that I am having difficult with and lack the references to look it up. Does anyone know of a good reference that I should add to my collection. I hate...

I am trying to answer a question that asks for the illumination level for the control room of an electric supply station. The answer is suppose to come from the NESC. When looking in the National Electrical Safety Code (NESC) 2007 Handbook by David J.Marne , the answer is suppose to be in NESC...

In Camara's Power Sample Exam Prob50, Exam#1, Afternoon: The problem asks for Thevenin's equivalent voltage, but the circuit has a capacitor in it. I have always thought one treats a capacitor as an open circuit and inductor as a short when doing Thevenin's equiv, but the solution treats the...

The size of overcurrent protective device required for a 645 Amp load is? I chose 600A. The choices were 600A or 700A. The correct answer was 700 Amps. According to the NEC 240.6 Standard Ampere Rating (A) Fuses and Fixed - Fixed-Trip Circuit Breakers there was both 600 and 700 included. Why...

The NEC has table 9 to lookup the resistances and reactances for 3 phase conductors. If I had to lookup this info for single phase, it does not exist in the NEC (or am I looking in the wrong place). Where would I find this info in the NEC? Do I use the 3 phase table for single phase conductors?