For those interested. This formula is the simplified form of the other mathematical one. If you substitute the angles of all 3 phases it will all reduce down to this formula.
Definitely my preferred method, especially as I had to turn the house upside down to find a protractor for the other methods LOL .... I love this journey you are taking us on from explaining atoms and electrons to DC and AC sine wave etc ..... I have even been making notes !!! can't wait to see where we end up.
My guess is that the formula only works with resistive loads (pf=1) or loads that have the same exact power factor, in which case the 3 currents would always be separated by 120 degrees. When you have different power factors, say 1, 0.8, and 0.7, the only way I know to mathematically find the neutral current is as explained by Joe in his first video. I would appreciate Joe's comments on this
Hello Professor I enjoyed watching your videos and you give us more options in calculating neutral current in unbalanced load. Very excellent explanation sir. Godbless.
Indeed, that's the method. My learners have just completed the 5357 / 103 principles written and almost all of them go for the calculation, but a few go with the equilateral triangle. They didn't like the look of the calculation when I first introduced it, since it took the whole width of the whiteboard, but once I broke it down, they realised it's quite easy
Nice, always interesting to hear how others approach these things, mine are still wading through the 103 learning, should be on the exam after the hols.
Thanks Joe, another well explained concept. I assume this is the mathematical equivalent of the graphical method 2 using Pythagoras (or whatever). I just feel that once the theory of three phase is fully understood - 120 degrees shift etc - you will be able to apply a mathematical solution to calculating the current in the Neutral. Don't really see the point of offering 4 different methods, other than to improve your maths skills.
WOW a very well explained method of calculating neutral current. This is a precise way getting a mathemathical value of neutral current. Thanks for sharing your knowledge and giving more options. Good job and Godbless.
Hey Professor, Can you explain how the given formula was mathematically derived? Or point me towards a place (a video or a Book) where I can find the explanation?
It is quite hard to read your shown calculation since they are grey pencil on slightly off-white paper. May I suggest that in the future you use something with greater contrast? Maybe black ink or marker or darker bold colors.
Each phase current for my question has a lag or lead to the voltage of each phase and the calculation isnt matching my phasor diagram calculation. Does this formula only work for in phase currents?
My guess is that the formula only works with resistive loads (pf=1) or loads that have the same exact power factor, in which case the 3 currents would always be separated by 120 degrees. When you have different power factors, say 1, 0.8, and 0.7, the only way I know to mathematically find the neutral current is as explained by Joe in his first video. I would appreciate Joe's comments on this
A three phase 400V four wire distribution board has the following loads connected:. - Red phase 8.8Kw - White phase 4.2 Kw - Blue phase 8.8Kw. Which of the following would be the neutral current?
You can use Casio fx-911EX as it has complex numbers. You can then just add the currents: 4.1 + 16.1
For those interested. This formula is the simplified form of the other mathematical one. If you substitute the angles of all 3 phases it will all reduce down to this formula.
Definitely my preferred method, especially as I had to turn the house upside down to find a protractor for the other methods LOL .... I love this journey you are taking us on from explaining atoms and electrons to DC and AC sine wave etc ..... I have even been making notes !!! can't wait to see where we end up.
That's the awesome thing about this subject, it just keeps on giving. Learning's a journey not a destination! Stay tuned for more! 😊👍
Delivering this tomorrow with the other methods, thank you.
My absolute pleasure, glad it helps. 😃
Wonderful. Would not know, did not know this formula.
Thanks for the nice comment!
My guess is that the formula only works with resistive loads (pf=1) or loads that have the same exact power factor, in which case the 3 currents would always be separated by 120 degrees. When you have different power factors, say 1, 0.8, and 0.7, the only way I know to mathematically find the neutral current is as explained by Joe in his first video. I would appreciate Joe's comments on this
Hello Professor I enjoyed watching your videos and you give us more options in calculating neutral current in unbalanced load. Very excellent explanation sir. Godbless.
Thanks very much for commenting, I'm glad the videos are helpful. 👍
I like your videos Mr Robinson. They're very resourceful
Good to know thanks!
Excellently explained Joe 👊😎👍💙
This is the method I teach. I also use a very simple method using an equilateral triangle.
Like the one at the end of this video? th-cam.com/video/fHiaui-ROik/w-d-xo.html
That'll teach me for not watching till the end (slaps wrist)
😂 Love it! Is it the same method you use?
Indeed, that's the method. My learners have just completed the 5357 / 103 principles written and almost all of them go for the calculation, but a few go with the equilateral triangle. They didn't like the look of the calculation when I first introduced it, since it took the whole width of the whiteboard, but once I broke it down, they realised it's quite easy
Nice, always interesting to hear how others approach these things, mine are still wading through the 103 learning, should be on the exam after the hols.
Thanks Joe, another well explained concept. I assume this is the mathematical equivalent of the graphical method 2 using Pythagoras (or whatever). I just feel that once the theory of three phase is fully understood - 120 degrees shift etc - you will be able to apply a mathematical solution to calculating the current in the Neutral. Don't really see the point of offering 4 different methods, other than to improve your maths skills.
I see your point, I think it's just a matter of giving someone a selection of tools and letting them pick the one they like best.
WOW a very well explained method of calculating neutral current. This is a precise way getting a mathemathical value of neutral current. Thanks for sharing your knowledge and giving more options. Good job and Godbless.
Hey Professor, Can you explain how the given formula was mathematically derived? Or point me towards a place (a video or a Book) where I can find the explanation?
Really great question Prem, I'll look into it. 👍
great. was well presented and simple
Thanks ,brilliant
Hi Joe!
Very good!
So we’ll explained!
Rgds mg.
Hai sir, thanks for this vedio. I am interested to know that, how the equation derived?
how do you work out the current in each L without doing a practical test?
Amazing as always 🕺
Hey everyone. I struggled to get the answer on my Helect. It shows 99.29. I don't know why and I don't have an SD button. Someone please help me!
What is a Helect please?
It is quite hard to read your shown calculation since they are grey pencil on slightly off-white paper. May I suggest that in the future you use something with greater contrast? Maybe black ink or marker or darker bold colors.
Each phase current for my question has a lag or lead to the voltage of each phase and the calculation isnt matching my phasor diagram calculation.
Does this formula only work for in phase currents?
My guess is that the formula only works with resistive loads (pf=1) or loads that have the same exact power factor, in which case the 3 currents would always be separated by 120 degrees. When you have different power factors, say 1, 0.8, and 0.7, the only way I know to mathematically find the neutral current is as explained by Joe in his first video. I would appreciate Joe's comments on this
Ma sha Allah. May Allah give you eman. Best teacher.
Thank you.
is not the formula: L1^2+L2^2+L3^2 - (L1XL2)+(L2XL3)+(L1XL3) all under square root?
Almost, you can express it as L1^2+L2^2+L3^2 -((L1×L2)+(L2×L3)+(L1×L3)) all square rooted, that double bracket is important. 😃
🤩
This is not working for me :-(
A three phase 400V four wire distribution board has the following loads connected:. - Red phase 8.8Kw - White phase 4.2 Kw - Blue phase 8.8Kw. Which of the following would be the neutral current?