Electrical Engineering: Ch 13: 3 Phase Circuit (46 of 53) Unbalanced Y-Load: Example

[@Jnglfvr]

As others have commented the wrong voltage was used to calculate the line currents. We're given that the line voltages are a balanced 120 V configuration. In a Y connected load the phase currents are the same as the line currents. Problem here is that the phase currents were calculated using line voltage instead of phase voltage. So the phase (and thus line) current should be equal to phase voltage/impedance. But the phase voltage in this case is the line voltage divided by sqrt(3) with phase shifted by - 30 degrees. That would make all the currents calculated above too large by a factor sqrt(3) with phase angle augmented by 30 degrees. So the correct line currents are Ia = 3.46< -30 Ib = 7.35< -182 and Ic = 5.48

[@gilbertvanheerswynghels5246]

In a star connection the line voltage are measured between the lines (220 V). phase voltage are measured between line and neutral (120 V). This calcultion is correct

[@Jnglfvr]

@@gilbertvanheerswynghels5246 Except that Va, Vb and Vc above are LINE voltages not PHASE voltages. It says, right at the top of the blackboard "LINE VOLTAGES." You must convert these line voltages to phase voltages in order to calculate phase currents! This calculation is NOT correct.

[@StannyMrKee]

​@gilbertvanheerswynghels5246 you're also confused

[@majoy3653]

Yeahh that should be 120/sqrt of 3

[@lrobertiii]

Hello Michel, I wanted to personally thank you for your videos. It's because of them, I was able to pass my mathematics and sciences courses, particularly Calculus Physics, and Astronomy, and get accepted into my dream college - the University of Michigan - one of the top science and engineering schools in America! I know you must get a lot of thanks but you really deserve it. Thank you so much.

[@MichelvanBiezen]

That is great news! We wish you all the best in Michigan. Thanks for sharing.

[@xxxx-fw2kk]

Why is there a " -" sign in the final equation for I(n). According to the diagram, I(n) should be the sum of I(a), I(b) and I(c) by KCL i.e. In=out?

[@bradenwallace6107]

Sir, this video is amazing. You present the information extremely clear and show all your work. I've been scouring the internet for hours trying to figure out how to do a problem like this since my professor could not explain any of the process and then I came across this video. Thank you!

[@MichelvanBiezen]

Thank you. I am glad you found us.

[@ninojohnjayme679]

correct me if I am wrong; aren't you supposed to use the Phase voltage in calculating the phase current?

[@sirtodip5272]

yeah i have this question too like if given voltage is vline, how to find vphase since we cant use relationship of surd3 angle 30 between vline and vphase? do we have to change to delta connection?

[@juswesaligan]

@@sirtodip5272 we can still use the relationship of squareroot of 3 here since we are dealing with the supply side which balanced.

[@billpulvera8817]

@ 0:07 the currents that he's calculating are line currents

[@Emaad_Ahmad]

Thank you very much sir. You explained the concepts in an efficient manner just before my exams. Hopefully you'll help with more videos. I'm pursuing B.E Electrical and Electronics Enginnering. You earned a subscriber! Cheers!

[@MichelvanBiezen]

Good luck on your exams!

[@MdUzzolHossain-e7d]

Very very important video for every electrical engineer. Thank you so much sir.

[@MichelvanBiezen]

We appreciate your feedback. Thank you. 🙂

[@chooper3048]

so the phase current whether its negative or positive will be base on the phase value of voltage . . thank you . . just an observation from Ic

[@keithto5990]

If the final neutral current is postive, it is means that the In current direction is flowing into the circuir?

[@omarsh77]

If both source and load are solidly grounded and if we assume a negligible resistance in the neutral wire, shouldn't the supply neutral and the load neutral be at the same potential i.e. neutral current = 0 A?

[@SteveW6SJK]

How about an example of an unbalanced delta connected load(s) on this wye system?

[@MichelvanBiezen]

We are still working on completing the other playlist.

[@JaykeSapalaran-iq3qs]

How did you get the 9.48 angle32.0 12.65 and -18.43??? How to press in calculator???

[@MichelvanBiezen]

The inverse tangent of (=4/12) = -18.43 degrees (Make sure your calculator is in degree mode and not in radian mode. )

[@JaykeSapalaran-iq3qs]

Thank you for teaching me ♥️🇵🇭👍

[@sagyshehata3616]

Great videos thank you so much for your effort

[@rchokelal]

Great Review. Took me back to 1993/4. Needed to be remined of the math....;)

[@remembering2739]

it would be phase voltage. not line voltege

[@MichelvanBiezen]

In a three phase system the line voltage (also known as the line-to-line voltage) is the votage between 2 phases (between 2 lines). The phase voltage is the difference between the phase and neutral.

[@AudioJunkie79]

Great video how would you find the current in each phase when there is no neutral?

[@MichelvanBiezen]

If there is no neutral, than the KCL at the junction becomes Ia + Ib + Ic = 0 (with the given current directions)

[@ArpanDutta-xv2dv]

can you please write the main question!!

[@heyman8820]

How would you do it if a neutral line impedance was given?

[@faizmalik9210]

You can use Millman's Theorem.

[@razuahamed6418]

Sir my question please answer me quickly,,,,,, if newtral point junction then karsaf law junction point, Ir+Ib+Ic=In but you write Ir+Ib+Ic+In=0 me don't understand.so please explain my question

[@MuhammadAbbas-pq3gw]

hit a like for sir's efforts

[@EngineersCalculatorTechnique]

The solution is correct the problem is wrong. The problem must be. a unbalanced 4 wire y connected load is supplied by a balanced 3 phase source 120v per phase.

[@Odyseee]

0:07 使用線電壓計算線電流

[@stanleycates1972]

A field engineer would measure the currents in each hot leg and the neutral. Then shift loads around to gain optimal balance.

[@michaelguo6349]

Jesus, this is so nice. Thanks a lot!!!

[@surendrakverma555]

Very good. Thanks 🙏🙏🙏🙏

[@MichelvanBiezen]

Most welcome

[@kannanr9016]

Awesome sir ....thank you so much sir. ...

[@tharakapanabokke4512]

Thank you!

[@MichelvanBiezen]

You're welcome!

[@supaluv3851]

Nice video

[@abhaynandanchaturbedi6798]

superb...

[@MichelvanBiezen]

Thank you! Cheers!

[@knowledgeispower8561]

Thank you sir very much I'm gonna subscribe now

[@MichelvanBiezen]

Thanks for the sub!

[@knowledgeispower8561]

No problem sir

[@Rashed_007]

thanks....

[@MichelvanBiezen]

You're welcome!

[@DulceSeeker]

splendid

[@MichelvanBiezen]

Glad you find our videos helpful. 🙂

[@kuzgunkuzgun7141]

Great

[@vimukthimadhusanka4806]

Thank you sir

[@MichelvanBiezen]

Welcome

[@error17.o22]

I think the method u did is wrong sir

[@aimgodyt7801]

yes this is wrong

[@danakaterinegomez7480]

@@aimgodyt7801 what would be the correct solution?

[@danakaterinegomez7480]

what would be the correct solution?

[@pratikrahate6227]

Yes it is wrong

[@danakaterinegomez7480]

@@pratikrahate6227 What would the correct solution?