Recent content by roadrunner

Okay thanks guys

I am doing some NEC problems and have a question on a portion. When calculation general lighting loads per Article 220 do you add 125% to the calculated VA's??? The solutions are adding 125% to the loads and stating "continuous duty". The problems are from a practice test using 2005 version...

Well maybe I the question is misprinted or something because the solutions they provide do not match that. I got $13,113 using F = A[ [(1+i)^n - 1] / i] I did find a solution it says: 1500[ [(1+.15) - 1] / [(.15)(1+.15)] ] + (3000)(1+.15)^-5 = 5028.23 + 1491.53 = 6519.76 **NOTE eedave...

I don't understand this question. Assume an effective interest rate of 15% per year compounded annually. An investment requires $1500 at the end of each year for the next 5 years plus a final investment of $3000 in 5 years. What is the equivalent lump sum investment now? A. $6100 B. $6500...

This was my first time taking the test and after the test I felt pretty confident of a passing grade. Now a few days have gone by the nerves are kicking in and making me feel not so confident. It is going to be a long wait..... Make sure you all don't discuss the questions on the test as that...

Thanks Flyer! Hope you know how important to this forum you are, your help is GREATLY appreciated

A synchronous generator is 3 phase wye connected and rated 1131 kva, 2.4 kv, 0.9 lagging. the output current from the generator at rated full load is most nearly: Why do you use the formula Sbase = Sq root 3 Vbase Ibase I just used the S=VI formula and got it wrong. Tad confused

Thanks but that is what I am doing but not getting the correct answer. I do most of my short circuit calcs using the MVA method but this one will not come out correctly. Could it be because I am given a impedance value for the transformer and a reactance value for the generator?? I thought i...

Can anyone give me the solution using the MVA method for this problem?!?!? Quick description if you don't have the book: A generating unit is shown in the figure. The 3 phase, short-circuit MVA contribution of G1 for a 230 kV bus is most nearly: Answer is 2290 figure layed out as...

Wow I really way over thought that one. Thanks for the speedy response and the great reminder to take a step back and look at the problem first before grabbing equations! Thanks again

Can anyone walk me through this question? 3phase induction motor and a 3 phase synchronous motor are connected to a 480V system. the synchronous motor, operating at 8kVA, 480V, 60 Hz is overexcited producing a leading pf of 0.7. the induction motor draws current of 14.43 A and has a lagging...