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WELL I HOPE YOUR CORRECT..I DO HAVE THE CONCEPTS DOWN AS WELL...OR AT LEAST I THINK I DO..EVERYTHING FROM PHASE SHIFTS TO COORDINATION OF RELAYS TO NEC..JUST HOPING FOR THE BEST

DO YOU HAVE AND RECOMMENDATIONS ON WHAT TYPE OF PROBLEMS, ODD PROBLEMS, ETC. THAT YOU LOOKED THROUGH YOURSELF THAT MAY BE HELPFUL?

i REALLY DONT FEEL LIKE i KNOW MUCH MORE THIS TIME...JUST MORE PRACTICE...WHICH WORRIES ME...THEY WERE SOME QUESTIONS ON THE EXAM THAT i HAD NO CLUE ABOUT OR WOULD KNOW WERE TO FIND OTHER THAN GOOGLE IN WHICH CASE I DONT HAVE ON THE EXAM..FOR EXAMPLE..THERE WAS AN IEEE QUESTION

i DID TAKE IT ONCE BEFORE...i THOUGHT i GOT LIKE AN 80 PERCENT..WRONG!...I THINK IT WAS LIKE A 48..I ONLY DID THE NCEES PRACTICE EXAM.

OH YEHA, i HAVE DONE THEM ENOUGH WERE i AM SCORING AT LEAST 95 % OR BASICALLY GETTING THEM ALL RIGHT AT THIS POINT

i HAVE THE NEC DOWN PRETTY WELL..EVERYTHING FROM MOTOR DISCONNECTS TO CONDUIT FILL IN CH.9...i HAVE A SECTION OF NOTES EACH FOR 3/1 PHASE POWER, LUMINAIRES, MOTORS, RELAYS, SYMMETRICAL COMPONENTS, NON-LINEAR ELECTRONICS, ENGR. ECON., TRANSFORMERS, FAULTS, LADDER LOGIC, GROUNDING, INSULATION TESTING?

I can now do Spinup, CI and NCEES exams pretty quickly....about 4 hrs on NCEES and a little less on CI's, probably 2 hours on spin-up...is this adequate enough? any other suggestions?

I have Wildi and I find no more details on this ....all the wildi books does is tell me in a d-y Xfmr, line voltages on y side secondary lead line voltages on delta primary side by 30 degrees. It doesnt say whether or not if its + or - sequence, which I think will affect it.

In grainger, pages 64-71 discusses phase shift between delta-y xfmrs....but is contradictory or I am just missing something. In figure 2.14 it says Vll y side leads Vll delta side by 30 with y being high side of a y-delta xfmr. Then page 68 it says when stepping up...in a delta-y or y...

Does anyone have this book..I am trying to see why the low-voltage side current lags by 30 degrees? the problem doesnt say the system is + or - sequence...dont you have to know this in this case?

I get I^2*(200*2) = 10,000...why do you add the 800?

Does it work like this: In either a delta-y or y-delta arrangement.....the line to line voltages on delta side lead line to line voltages on y-side by 30 degrees if + sequence a,b,c and the line to line voltages on delta side lag line to line voltages on y-side by 30 degrees if - sequence a,c, b?

Does this 30 degrees phase shift occur with the voltage and current? I have read some stuff on it, just trying to get it squared away. If I had said + sequence or - sequence in my question, would that have helped?

Gentleman/Ladies: I am trying to figure out the phase shift of voltages and currents in transformers...specifically in delta-wye or wye-delta. Attached is a file were I showed and tried to keep simple the line currents and voltages on both sides of a transformer. My question is...what will be...

if I have a phasor value of voltage = 120@ 120 degrees and say current = 10@-45 degrees lagging...how can I convert these to rms values....is it just add -30 or 150 degrees to each angle?

If it were 1-phase, did I do it correctly?

I understand that...but am I right in my thinking of how to do it if its 3 phase or single phase is the question?

I have a problem statement: A system has S_base = 100 MVA, calculate the base current for V_Base = kV 230. They calculate it: I_Base = (100 MVA* 1000) / ( sqrt (3) * 230 kV) = 251 amps...... The statement doesnt say its 3 phase...so I went I_Base = (1000 * 100 MVA) / 230 Kv = 434 amps so...

If im given a delta 240/120 volt 3-phase load, and I want to model it as one phase.....line to neutral as if there is a neutral, like we can also do with WYE.....would I divide by sqrt(3) to get the line to neutral voltage value to use or would I use 120 volts.....when calculating parameters of...

Im getting confused on some of the 3 phase power equations. For example.... s(3Phase) = V_ll x I_l x sqrt(3) Also, s(3phase) = 3 x V_phase x I_phase....= 3 x V_ll x I_ll....what or when do you know when to use these different equations? Is the 2nd equation for calculating S across each phase...