Search results

Attached are my notes for the different types of harmonics (positive-sequence, negative-sequence, and zero-sequence harmonics) from Zach Stone's Electrical PE Review, and my notes on problem 112. The correct answer choice is (D). Positive-sequence currents and negative-sequence currents are...

Attached are my notes about how surge protective devices (SPDs) work, from the Engineer Pro Guides final exam (practice exam) that I previously studied from. Basically, an SPD is connected in parallel of and in front of the load to be protected. When I say in front of, I mean from the reference...

Attached are some of my notes from various textbooks and other practice exams regarding how the CTs are connected for 3-phase delta/wye transformers. The CTs on the Y side of a transformer are connected in delta. The CTs on the delta side of a transformer are connected in Y. The reason for the...

Yes, when going from line-to-line voltages to line-to-neutral voltages. The basic formula converting between these two voltages are: V LL = √3 x V LN x <+30 deg V LN = (V LL / √3) x <-30 deg In this problem, the given voltages are stated to be line-to-line. I'm doing an equivalent per-phase...

Congrats! For some reason I thought you already passed LOL

You can download visible attachments and then open them up separately and zoom in on them further if needed... Does this not work for you?

I think the links got broken when EngineerBoards updated their website. I think this update happened about a month or 2 months ago. Attached are my notes and work for these two problems, as a friendly FYI.

Also attached are some notes and information I have about the capacitor and charging current in a rectifier circuit. I learned this from Zach Stone's Electrical PE Review. Remember from circuit fundamentals that a capacitor is able to hold/store a voltage. So when the input or source AC...

This problem is a bit hard to explain. I tend to have a more difficult time explaining power electronics. Attached is my work and notes for this problem (this was problem 113 in the previous version of the NCEES PE Power practice exam).

Hey all. As a friendly FYI, attached is my work on problem 122. I broke this problem down by each interval (each 15-minute interval): For each interval, I listed the maximum demand and the average demand. In each interval, the average demand is the area under the graph, within each 15-minute...

Some texts/materials have the neutral current In traveling in the same direction as the phase currents, such that the phase currents and neutral current all flow towards the neutral connection point of a wye. I believe the NCEES PE practice exam uses this reference for the neutral point. So if...

Only because I did a lot of repetitive/repeat problem solving with the NCEES practice exam and other sample practice exams I had. I studied for about a year due to my original exam dates being pushed back because of CoViD.

I should also mention that for this problem, you need to look primarily at NEC Section 430.24. This section specifically covers branch circuits consisting of a combination of motor loads and/or non-motor loads, which this problem is all about. NEC 430.24 for combination motor and non-motor...

Off the top of my head, since I don't have this problem right in front of me: The current needed for the heater is simply 1 KW divided by 240 V. So that is: 1000 W / 240 V = 4.167 A For the motor, you need to use the Motor Tables at the end of NEC Section 430 to find the FLC (full load...

I just posted this in another topic, attached are 2 different methods I used to solve NCEES problem 530 (which became question 70 in the updated practice exam).

For NCEES problem 531, attached is what I did to find the total 3-phase reactive power losses dissipated in the line. I essentially used Q line 3-ph = 3 * I^2 * X.

Attached is my work on how I solved problem 530 using 2 different methods. The 0.025 is the per-unit impedance of the utility. It comes from the following: The utility has a line-to-line voltage of 12.47 KV and a 3-phase fault duty (available 3-phase fault short circuit power) of 40 MVA. So...

Normally in a balanced 3-phase system, the phase currents - which are fundamental-sequence currents, also known as 1st harmonic positive-sequence currents - cancel out at the neutral connection point. This is because of the 120-degree displacement between each phase in a balanced 3-phase system...

Use this link: https://engineerboards.com/threads/ncees-power-pe-exam-64.36947/ I posted my explanation of the solution to this problem on this link.

For a single-line-to-ground fault (also called a single-phase-to-ground fault), the overall sequence network diagram has the positive (Z1), negative (Z2), and zero (Z0) sequence impedances all in series. So here: Z = Z1 + Z2 + Z0 Z = Z1 + Z1 + 10Z1 = 12 * Z1 Since the sequence networks are in...