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Be familiar on how to do voltage drop calcultions.

I finally passed the PE - power. Thanks to all on here. This was the most helpful resource i had. I also want to add a special thank you to Cableguy.

I finally passed the PE - power. Thanks to all on the EB.com especially to Cableguy.

Any better explanation, guidance to answering this question?

I don't believe so. You should take a look at the syllabus in the NCEES PE power sample question booklet. These topics are not included.

Boy oh boy am i lost.... How did u conclude the rotor is driven in the opposite direction? And since i did not grasp the concept yet, i don't know what will happen if it's a 6 pole machine.

A 3 ph, 4 pole synchronous motor and a 3 ph 4 pole slip ring induction motor are mechanically coupled. Their stators are also connected to a balanced 3 ph 60 hz supply. A 3 ph resistive load is connected across the slip rings. The frequency of the current in the resistive load is? a)30Hz b)60Hz...

Thank you Dark knight!!

Dark Knight, do u still have this question and solution available? I will like a copy. Thanks

Problem 18 Per 2008 NEC code section 430.32(1), for motors with service factor 1.15 or greater 1.25 * 28 = 35A and not 1.4 * 28 = 39.2A as indicated. Problem 19 Per 2008 NEC code section 430.32(1) for motors with temp rise over 40 deg, all other motors 1.15 * 26 = 29.9 and not 1.3 *26 = 33.8

Be careful with this article, example 18 and 19 are also incorrect.

The example number 11 " What is the ampacity of a #10 ZW2 conductor in a raceway with 5 current carrying conductors?" They have an answer of 32 amps. Does anyone think it's incorrect? I got 30amps ( see table 310.16 and 240.4D) X 0.8 (see table 310.15.B.2.a) = 24amps

The linke below might be a starting point http://www.mpoweruk.com/performance.htm

Any suggestions where to find sample problems on this topic? Or anyone has some sample problems they could share? Thanks

I hope it does not make it to the PE but best be prepared than sorry u didn't. I am still struggling to understand the algerbraic soloution. Can you clarify what u meant by {"This means at full load, you have a phasor magnitude of 92 amps, with a j28 reactive component, along with an 87.x...

Ques: A 3 phase induction motor draws 28A at no load and 92A at full load. What is the power factor of the motor at half load?

Motor: P = 75hp x 0.746kW/hp / 0.905 = 61.82kW pf = acos(0.895) = 26.49º Q = P tan(angle) = 61.82kW tan(26.49º) = 30.81kVAR Okay not sure if this is an obvious answer or not Why did you use the input power for the motor and not the output power to calculate the sytem KW?

Can someone share what the voltage relationship will be for an ideal transformer with two secondary windings and one primary windings. I know for current it is Np * Ip = (Ns1 * Is1) + (Ns2 * Is2) Thanks

I see what you are saying. I was working some sample problems and i used the the grainger formula but my answers did not match any of the proposed answers. When i looked at the solution in the book, the answer used Zbase equal (Vbase, KV)^2/ (Sbase, KVA). Not sure why they did that. That's...

Power system analysis by grainger provides the formula (1.55) P.U Impedance =[ (actual impedance, ohm) x (base KVA)] / [(base voltage, Kv)^2 * 1000] If you do a derivation for PU Impdance = Zactual/Zbase where Zbase = (Vbase, KV)^2/ (Sbase, KVA) you get thesame result as shown above without...