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4. ### Alabama Changes Licensing Requirements

Senate Bill 316 has been signed by the Governor, making it Act 2018-550. This Act is in regards to the Alabama Board of Licensure for Professional Engineers and Surveyors. It encompasses a number of changes, but the most important change made was with respect to the sequence of events that need...
5. ### Conductors for Power

There are two types of grounds in an electrical system. You have the Equipment Grounding Conductor (EGC) and Grounding Electrode Conductor (GEC). NEC Article 100 Definitions (Italicized text is my additional information): Equipment Grounding Conductors (EGC) - The conductive path(s) that...
6. ### Engineering Economy

I'm not trying to give anything away - I'm just trying to say that Engineering Economy questions on the PE are kind of "softball" questions compared to the FE exam where they were wanting to make sure you understood the underlying principles of "Engineering Economics." I don't know how to speak...
7. ### Engineering Economy

HA! I thought the FE Engineering Economics was more comprehensive, while the the PE was much simpler. If you did well on the FE Engineering Economics problems, you'll have no trouble with the PE.
8. ### Help explain Lagging/Leading PF

It might help to think of "leading" vs. "lagging" in terms of current and voltage instead of positive and negative. Power factor is generally used in calculations as an absolute value, so the sign of the PF is irrelevant. A leading power factor means the current is "leading" the voltage (i.e...
9. ### Graffeo - Single Phase Problem

Yep, that's true. The three phases serve as return paths for each other, but I think dwelling on this too much will just create more confusion than necessary for people trying to prepare for the exam when all they want to know is why a single phase VD calculation counts the conductor length...
10. ### Graffeo - Single Phase Problem

In a single-phase system, current travels to the load on the line conductor and returns on the neutral conductor, so this "series" circuit voltage is dropped across both the line and neutral conductors. In a three-phase system, you have two conditions: balanced and unbalanced. In a balanced...
11. ### RMS value of a DC offset saw tooth wave

I can tell English is a second language for you, but the mathematics language is universal. You post good work on here, @rg1...I have no doubts about your passing. @cos90 is also mathematically strong. Both of you guys will do well. Just don't make the mistake of overthinking things. The...
12. ### RMS value of a DC offset saw tooth wave

Agreed. I predict both of you will pass your PE Exams, and will have plenty of time to play with this later.
13. ### Complex Imaginary Test 1 Problem 1

You're right. I missed the connection. I interpreted the question as what would be the peak voltage of the given phase voltage at Vab (perhaps that was the intended question), but the question simply asks what what is the peak voltage at Vab, so your answer is right. I think you meant 400 *...
14. ### Complex Imaginary Test 1 Problem 1

Here is a brief explanation: https://electronics.stackexchange.com/questions/12453/if-a-standard-three-phase-400v-ac-connection-is-rectified-what-dc-voltage-comes
15. ### Complex Imaginary Test 1 Problem 1

Where you have your voltmeter in your sketch will read sqrt3 * 125V, or 216.5V...that is not where Vab is measured from. Vab is measured from the outputs of the rectifier, as shown in my attachment.
16. ### Graffeo - Single Phase Problem

The "1 is 2 and 3 is 1" monicker means "single phase counts 2 times the conductor length and 3 phase counts 1 times the conductor length." The OP was confused about why the conductor length was doubled.
17. ### Complex Imaginary Test 1 Problem 1

I guess what I'm trying to say is that the load isn't seeing the line-to-line rectified voltage...it's seeing the sum of three single-phase voltages that have been fully rectified, so each rectified phase voltage is simply sqrt 2*Vrms. There could be 6 or 1,000 phases that were fully...
18. ### Autotransformer Problem

Probably a better way to say this is that a standard transformer couples voltage from the primary side to the secondary side by electromagnetic induction. This electromagnetically coupled voltage induces a current on the secondary. Since power in must equal power out, the amount of current...
19. ### Autotransformer Problem

No, not overloaded...the single phase transformer used as an Autotransformer allows the total capacity to be fully realized. You started out with a single-phase transformer rated for 15kVA, but through a clever use of the law conservation of energy, you unlocked the true and total capacity of a...
20. ### Graffeo - Single Phase Problem

All of these explanations are great and completely valid. To make this easy to remember for instant recall during the exam, use this: "Single-Phase is Two Times, and Three-Pase is One Times." ...or, "1 is 2 and 3 is 1." Kinda clumsy, but it got me through Circuits II. ?