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I'm trying to calculate Susceptance and conductance values for a three phase transformer using the field test report. I have excitation current in % (i believe % based on name plate current rating). Voltage is 100% and no load losses in KW. I'm trying to convert everything to per unit and then...

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Does charging current due to line-ground capacitance decrease as tower height increases?

I bought the 2012 NESC by IEEE. Is this the correct book for the exam? There are tone of books that say NESC and by different authors and some for electricians etc.

I'm planning to take a bunch of text books which have notes written in them using pencil. Would it be problem?

Can someone please show the solution? G1 has no load frequency of 61.5hz and a slope of 1MW/Hz. G2 has no load frequency of 61hz and a slope of 1MW/Hz The two generators are supplying a real load totalling 2.5 MW at 0.8pf lagging. a) at what frequency is system operating and how much power is...

what types of buses are the controlled side and controlling side of a tap changing transformer. I understand that fixed transformer would fall under load buses.

Spin up exam -4, Q 59 says DC machines do not have hysteresis losses as hysteresis is a characteristic of alternating current. My reason is DC machines inherently produce AC current, which is rectified using commutator so it has hysteresis losses in the stator core. Can someone tell me what is...

For calculating neutral currents, In=-(Ia+Ib+Ic). Can anyone explain why B is leading A by 120 and C is leading A by 240? I would assumed B lagging A by 120 and C lagging A by 240 for ABC sequence (assumed as phase sequence not given)

in a three phase system, phase A has phase to neutral load of 60 KW at 1pf, phase B has phase to neutral load of 72 KW at 1PF and Phase c to neutral load is 50 KW at 1 PF. To find single phase branch current Ia=60/(480/1.732) Ib=72/(480/1.732)=259.8 ang(-120) Ic=50/(480/1.732)=180.4 ang(120)...

Does any one have good reference material on parallel generators and different modes of operation? I did google search, but I couldn't find one document that covers both isochronous and droop mode operations. I would appreciate if you can share any material you may have.

When motor Service Factor is given, in order to get the branch rating, do we multiply the NEC stipulated percentage with the Service factor or just use NEC % motor Full load amps required for branch circuit rating?

I thought I had this figured out, but the Chalapti book seems to be doing it differently. A building is supplied by a 480 V four wire service. The building has a 3 phase motor load of 185 kW at 0.8pf. What is line current? I=185(ang-36.86)/(1.73*480(ang30)*0.8) Why are they including the...

I thought I had this figured out, but the Chalapti book seems to be doing it differently. A building is supplied by a 480 V four wire service. The building has a 3 phase motor load of 185 kW at 0.8pf. What is line current? I=185(ang-36.86)/(1.73*480(ang30)*0.8) Why are they including the...

Can someone explain the answers?

I thought Buck transformer is same as Step down transformer, am I right?

NEC has two temperature correction tables 310.15(B)(2)(a) and 310.15(B)(2)(b), table-a for 30C ambient and table-b for 40 C ambient. Under what conditions do we use each of these tables?

I have been consistently getting 70-80% in the NCEES and Complex imaginary in the first round of working out the exams. Is it score any good?

Many of you on this forum mentioned that you have used NEMA standards. Can you specify which ones you actually took to the exam? I'm guessing the ones on Motor. Also, I created an account on the NEMA website, but I couldn't find the design guides for Motor, I remember seeing them some time ago...

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