Neutral Current Formula
- Thread starter tkb
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
You only need the phase currents.
Neutral current is the square root of the sum of the following things:
Neutral current is the square root of the sum of the following things:
- Phase A current squared, plus
- Phase B current squared, plus
- Phase C current squared, MINUS
- Phase A current times Phase B current, MINUS
- Phase A current times Phase C current, MINUS
- Phase B current times Phase C current.
brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
- Location
- New Jersey
- Occupation
- Journeyman Electrician
40,000+40,000+40,000=120,000
120,000-(40,000-40,000-40,000)=0
SQ Root of 0=0
Charlie or Roger's formula
120,000-(40,000-40,000-40,000)=0
SQ Root of 0=0
Charlie or Roger's formula
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
You mis-represented my formula. Why did you put parentheses around any of my terms? I did not.
My formula, if translated from words into symbols, would be
√A?+B?+C?-A*B-B*C-A*C
This is the same as,
√(A?+B?+C?)-(A*B+B*C+A*C)
Thus, what I wrote in words, and what Brian showed with symbols, are the same thing.
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- Location
- New Jersey
- Occupation
- Journeyman Electrician
Not exactly, Brian's formula use *2 instead of squared.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Semantics. The asterisk character is often used to denote the square function. I think it's a leftover from early Basic or Fortran programming, but that memory has faded beyond recall.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
very nice.
cool tool. i am curious, what values would produce the largest current flow on a neutral ? i tried Ia=0,Ib=10,Ic=20, for a 20 amp circuit, just for fun and got 17.33 for In. just curious what max In could be?brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
He didn't use * symbol either
In my original formula I used a squared symbol it did not transpose into Paint SORRY
- Location
- Illinois
- Occupation
- retired electrician
The maximum neutral current is when you have one or two of the ungrounded conductors fully loaded. In both cases the neutral current will be the same as the ungrounded conductor current.very nice.
Use the Print Screen key to copy an image of your screen to the Clipboard, or use Alt+Print Screen for an image of the active application. Paste into Paint and crop or otherwise modify to suit before saving to file.
If you are using Windows Vista, the Snipping Tool allows the user to capture any area of the screen. You can then Copy it to an image app or simply save it directly to an image file: PNG, JPEG, GIF, and/or a single file web page (*.MHT).
Additionally, Insert Equation or Insert Object > MS Equation in Office programs does a decent job of making formulas in true mathematical form...
Last edited:
brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
Use the Print Screen key to copy an image of your screen to the Clipboard, or use Alt+Print Screen for an image of the active application. Paste into Paint and crop or otherwise modify to suit before saving to file.
If you are using Windows Vista, the Snipping Tool allows the user to capture any area of the screen. You can then Copy it to an image app or simply save it directly to an image file: PNG, JPEG, GIF, and/or a single file web page (*.MHT).
Additionally, Insert Equation or Insert Object > MS Equation in Office programs does a decent job of making formulas in true mathematical form...
I did this or tried to it did not transpose?????
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